Initial commit

2026-07-12 13:43:37 +02:00
commit 0c9ad846f4
28 changed files with 1518 additions and 0 deletions
@@ -0,0 +1,73 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    tags:
+      - 'v*'
+    branches:
+      - develop
+      - 'feature/*'
+  workflow_dispatch:
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Compute image name and tag
+        id: compute-tag
+        run: |
+          REGISTRY=$(echo "${{ github.server_url }}" | sed 's|https\?://||')
+          OWNER=$(echo "${{ github.repository_owner }}" | tr '[:upper:]' '[:lower:]')
+          ACTOR=$(echo "${{ github.actor }}" | tr '[:upper:]' '[:lower:]')
+          IMAGE_NAME="javadocviewerservice"
+          FULL_IMAGE="${REGISTRY}/${OWNER}/${IMAGE_NAME}"
+
+          REF="${{ github.ref_name }}"
+          if [[ "${REF}" == v* ]]; then
+            TAG="${REF#v}"
+            TAGS="${FULL_IMAGE}:${TAG},${FULL_IMAGE}:latest"
+          else
+            TAG=$(echo "${REF}" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9._-]/-/g')
+            TAGS="${FULL_IMAGE}:${TAG}"
+          fi
+
+          echo "Registry:  ${REGISTRY}"
+          echo "Actor:     ${ACTOR}"
+          echo "Tags:      ${TAGS}"
+
+          echo "registry=${REGISTRY}" >> "$GITHUB_OUTPUT"
+          echo "actor=${ACTOR}" >> "$GITHUB_OUTPUT"
+          echo "image=${FULL_IMAGE}" >> "$GITHUB_OUTPUT"
+          echo "tag=${TAG}" >> "$GITHUB_OUTPUT"
+          echo "tags=${TAGS}" >> "$GITHUB_OUTPUT"
+
+      - name: Network Debug
+        run: |
+          curl -v https://git.mein-gateway.de/v2/    
+
+      - name: Debug Secret
+        run: |
+         echo "Secret length: ${#TOKEN}"
+        env:
+          TOKEN: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Log in to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: git.mein-gateway.de
+          username: thischwa
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.compute-tag.outputs.tags }}
@@ -0,0 +1,43 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+.kotlin
+
+### IntelliJ IDEA ###
+.idea/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
+
+## local ##
+/database/
+/javadoc-storage/
+/jdvs.yml
+/.claude/
+/info.txt
@@ -0,0 +1,33 @@
+# JavadocViewerService
+
+## Tech Stack
+
+- **Java 21**
+- **Spring Boot 4.x** (spring-boot-starter-parent)
+  - Spring MVC (spring-boot-starter-web)
+  - Spring Data JPA (spring-boot-starter-data-jpa)
+  - Thymeleaf (spring-boot-starter-thymeleaf)
+  - Bean Validation (spring-boot-starter-validation)
+  - Liquibase (spring-boot-starter-liquibase)
+- **H2** — file-based embedded database (`./database/jdvsdb`)
+- **Lombok** — boilerplate reduction (`@Data`, `@RequiredArgsConstructor`, `@Slf4j`)
+- **JGit 7.x** — Git operations (clone, fetch, tag resolution)
+- **Jackson YAML** — parsing of `jdvs.yml` config file
+- **Maven** — build tool
+
+## Configuration
+
+- `application.yml` — base configuration (datasource, JPA, default jdvs properties)
+- `jdvs.yml` — external runtime config (repositories, property overrides); imported via `spring.config.import`
+
+## Package Structure
+
+- `codes.thischwa.jdvs.config` — `@ConfigurationProperties` beans
+- `codes.thischwa.jdvs.service` — business logic (Git, Javadoc generation, scheduling)
+- `codes.thischwa.jdvs.jpa` — Spring Data repositories
+- `codes.thischwa.jdvs.model` — JPA entities
+- `codes.thischwa.jdvs.web` — MVC controllers and `WebMvcConfigurer`
+
+## Coding
+
+The generated code follows the principles of clean architecture and follows the SOLID principles. It is designed to be modular, testable, and maintainable. The code is written in a way that promotes readability and reduces complexity. It uses modern Java features and best practices to ensure efficient and reliable operation. To formate the code use che checkstyle definition in [google_custom_checks.xml](src/checkstyle/google_custom_checks.xml). Each changing of code must be verified with compiling.
@@ -0,0 +1,32 @@
+# Stage 1: Build the JAR using Maven
+FROM maven:3.9-eclipse-temurin-21 AS builder
+
+LABEL org.opencontainers.image.description="JavadocViewerService serves and manages Javadoc documentation from Git repositories."
+
+WORKDIR /build
+
+# Copy pom.xml and download dependencies first (for Docker cache)
+COPY pom.xml .
+RUN mvn dependency:go-offline
+
+# Copy the full source tree and build the application
+COPY src ./src
+RUN mvn clean package -DskipTests
+
+# Stage 2: Minimal runtime image
+FROM eclipse-temurin:21-jdk-jammy
+
+WORKDIR /app
+
+# Install tini and Maven
+RUN apt-get update && apt-get install -y tini maven && rm -rf /var/lib/apt/lists/*
+
+# Copy the built jar from the builder stage
+COPY --from=builder /build/target/*.jar /app/jvs.jar
+
+VOLUME ["/app/javadoc-storage", "/app/database"]
+
+EXPOSE 8080
+
+ENTRYPOINT ["/usr/bin/tini", "--"]
+CMD ["java", "-jar", "jvs.jar"]
@@ -0,0 +1,16 @@
+MIT No Attribution
+
+Copyright <YEAR> <COPYRIGHT HOLDER>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this
+software and associated documentation files (the "Software"), to deal in the Software
+without restriction, including without limitation the rights to use, copy, modify,
+merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
@@ -0,0 +1,77 @@
+# JavadocViewerService
+
+## Preface
+
+This project Spring Boot web service that automatically fetches, manages, and serves Javadoc documentation for Maven artifacts.
+
+If you encounter any bugs or find missing features, feel free to report them on
+the [GitHub Issues page](https://github.com/th-schwarz/JavadocViewerService/issues).
+
+## Features
+
+- Retrieves Javadoc JARs from Maven Central or custom Maven repositories
+- Tracks multiple Maven artefacts with version detection (only the latest version is taken into account).
+- Delivers generated Javadoc content via a simple bootstrap web interface
+- Scheduled updates via a configurable cron expression
+
+## Requirements
+
+At least JRE-21 or docker
+
+## Start
+### ... with Java
+
+```bash
+java -jar jdvc-<version>.jar --spring.config.import=file:./jdvs.yml
+```
+
+### .. with Docker
+
+```yaml
+services:
+  jvs-dockerized:
+    image: git.mein-gateway.de/thischwa/javadocviewerservice:develop
+    volumes:
+      - /opt/javadocviewerservice-dockerized/jdvs.yml:/app/jdvs.yml:ro
+      - /opt/javadocviewerservice-dockerized/database:/app/database
+      - /opt/javadocviewerservice-dockerized/javadoc-storage:/app/javadoc-storage
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:8086:8080"
+```
+
+Volume mapping:
+
+| Mount | Purpose |
+|---|---|
+| `jdvs.yml:/app/jdvs.yml:ro` | Injects the repository configuration (which artifacts to track) as read-only — the only file you need to edit |
+| `database:/app/database` | Persists the H2 database so tracked version metadata survives restarts and image updates |
+| `javadoc-storage:/app/javadoc-storage` | Persists generated Javadoc HTML so it is not lost on container recreation |
+
+
+## Configuration
+
+### `application.yml`
+
+Key defaults:
+
+| Property | Default                          | Description                        |
+|---|----------------------------------|------------------------------------|
+| `jdvs.base-dir` | `./javadoc-storage`              | Storage root for generated Javadoc |
+| `jdvs.cron` | `0 0/30 * * * ?`                 | Update schedule (every 30 min)     |
+| `jdvs.clean-on-start` | `false`                          | Wipe storage and DB on startup     |
+| `jdvs.run-on-start` | `false`                          | Run update immediately on startup  |
+| `jdvs.maven-central-url` | `https://repo1.maven.org/maven2` | Default Maven repository           |
+
+### `jdvs.yml`
+
+Defines the repositories to track and individual settings (all key defaults can be overridden):
+
+```yaml
+jdvs:
+  repositories:
+    - name: my-lib
+      group-id: com.example
+      artifact-id: my-lib
+      # maven-repo-url: https://custom.repo/maven  # optional, defaults to Maven Central
+```
@@ -0,0 +1,144 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>codes.thischwa</groupId>
+    <artifactId>jdvc</artifactId>
+    <version>0.2.0-SNAPSHOT</version>
+
+    <name>JavadocViewerService</name>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>4.0.5</version>
+        <relativePath />
+    </parent>
+
+    <properties>
+        <java.version>21</java.version>
+        <maven.compiler.source>${java.version}</maven.compiler.source>
+        <maven.compiler.target>${java.version}</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <issueManagement>
+        <url>https://git.mein-gateway.de/thischwa/JavadocViewerService/issues</url>
+        <system>Gitea Issues</system>
+    </issueManagement>
+
+    <scm>
+        <developerConnection>scm:git:https://git.mein-gateway.de/thischwa/JavadocViewerService.git</developerConnection>
+        <connection>scm:git:https://git.mein-gateway.de/thischwa/JavadocViewerService.git</connection>
+        <url>https://git.mein-gateway.de/thischwa/JavadocViewerService</url>
+        <tag>HEAD</tag>
+    </scm>
+
+    <distributionManagement>
+        <repository>
+            <id>mygitea</id>
+            <url>https://git.mein-gateway.de/api/packages/thischwa/maven</url>
+            <releases>
+                <enabled>true</enabled>
+            </releases>
+        </repository>
+        <snapshotRepository>
+            <id>mygitea</id>
+            <url>https://git.mein-gateway.de/api/packages/thischwa/maven</url>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+        </snapshotRepository>
+    </distributionManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-thymeleaf</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-liquibase</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.eclipse.jgit</groupId>
+            <artifactId>org.eclipse.jgit</artifactId>
+            <version>7.2.1.202505142326-r</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok</artifactId>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-source-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>attach-sources</id>
+                        <goals>
+                            <goal>jar-no-fork</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <!-- build the fat jar -->
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <configuration>
+                    <excludes>
+                        <exclude>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok</artifactId>
+                        </exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
@@ -0,0 +1,484 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!--
+    Checkstyle configuration that checks the Google coding conventions from Google Java Style
+    that can be found at https://google.github.io/styleguide/javaguide.html
+
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.org (or in your downloaded distribution).
+
+    To completely disable a check, just comment it out or delete it from the file.
+    To suppress certain violations please review suppression filters.
+
+    Authors: Max Vetrenko, Mauryan Kansara, Ruslan Diachenko, Roman Ivanov.
+ -->
+<!-- version: 13.1.0 -->
+
+
+<module name="Checker">
+
+    <property name="charset" value="UTF-8"/>
+
+    <property name="severity" value="${org.checkstyle.google.severity}" default="warning"/>
+
+    <property name="fileExtensions" value="java, properties, xml"/>
+    <!-- Excludes all 'module-info.java' files              -->
+    <!-- See https://checkstyle.org/filefilters/index.html -->
+    <module name="BeforeExecutionExclusionFileFilter">
+        <property name="fileNamePattern" value="module\-info\.java$"/>
+    </module>
+
+    <module name="SuppressWarningsFilter"/>
+
+    <!-- https://checkstyle.org/filters/suppressionfilter.html -->
+    <module name="SuppressionFilter">
+        <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
+                  default="checkstyle-suppressions.xml" />
+        <property name="optional" value="true"/>
+    </module>
+
+    <!-- https://checkstyle.org/filters/suppresswithnearbytextfilter.html -->
+    <module name="SuppressWithNearbyTextFilter">
+        <property name="nearbyTextPattern"
+                  value="CHECKSTYLE.SUPPRESS\: (\w+) for ([+-]\d+) lines"/>
+        <property name="checkPattern" value="$1"/>
+        <property name="lineRange" value="$2"/>
+    </module>
+
+    <!-- Checks for whitespace                               -->
+    <!-- See http://checkstyle.org/checks/whitespace/index.html -->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <module name="LineLength">
+        <property name="fileExtensions" value="java"/>
+        <property name="max" value="140"/>
+        <property name="ignorePattern"
+                  value="^package.*|^import.*|href\s*=\s*&quot;[^&quot;]*&quot;|http://|https://|ftp://"/>
+    </module>
+    <!--  Suppression to prevent LineLength Check from flagging lines in Text-blocks -->
+    <module name="SuppressWithPlainTextCommentFilter">
+        <property name="checkFormat" value="LineLength"/>
+        <property name="offCommentFormat" value='^.*"""\s*$'/>
+        <property name="onCommentFormat" value='^\s*"""\s*(?:[,;]|.+)$'/>
+    </module>
+    <module name="TreeWalker">
+        <module name="OuterTypeFilename"/>
+        <module name="MatchXpath">
+            <property name="id" value="singleLineCommentStartWithSpace"/>
+            <property name="query"
+                      value="//SINGLE_LINE_COMMENT[./COMMENT_CONTENT[not(starts-with(@text, ' '))
+                       and not(starts-with(@text, '/'))
+                       and not(@text = '\n') and not(ends-with(@text, '//\n'))]]"/>
+            <message key="matchxpath.match" value="''//'' must be followed by a whitespace."/>
+        </module>
+        <module name="IllegalTokenText">
+            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL, TEXT_BLOCK_CONTENT"/>
+            <property name="format"
+                      value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|20|22|27|5(C|c))|\\(0(10|11|12|14|15|40|42|47)|134)"/>
+            <property name="message"
+                      value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+        </module>
+        <module name="AvoidEscapedUnicodeCharacters">
+            <property name="allowEscapesForControlCharacters" value="true"/>
+            <property name="allowByTailComment" value="true"/>
+            <property name="allowNonPrintableEscapes" value="true"/>
+        </module>
+        <module name="AvoidStarImport"/>
+        <module name="OneTopLevelClass"/>
+        <module name="NoLineWrap">
+            <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
+        </module>
+        <module name="NeedBraces">
+            <property name="tokens"
+                      value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
+        </module>
+        <module name="LeftCurly">
+            <property name="id" value="LeftCurlyEol"/>
+            <property name="tokens"
+                      value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
+                    INTERFACE_DEF, LAMBDA, LITERAL_CATCH,
+                    LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF,
+                    OBJBLOCK, STATIC_INIT, RECORD_DEF, COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="LeftCurly">
+            <property name="id" value="LeftCurlyNl"/>
+            <property name="option" value="nl"/>
+            <property name="tokens"
+                      value="LITERAL_CASE, LITERAL_DEFAULT"/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <!-- LITERAL_CASE, LITERAL_DEFAULT are reused in SWITCH_RULE  -->
+            <property name="id" value="LeftCurlyNl"/>
+            <property name="query" value="//SWITCH_RULE/SLIST"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlySame"/>
+            <property name="tokens"
+                      value="LITERAL_TRY, LITERAL_CATCH, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <property name="id" value="RightCurlySame"/>
+            <property name="query" value="//RCURLY[parent::SLIST[parent::LITERAL_CATCH
+                               and not(parent::LITERAL_CATCH/following-sibling::*)]]"/>
+        </module>
+        <module name="RightCurly">
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="option" value="alone"/>
+            <property name="tokens"
+                      value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF, LITERAL_SWITCH, LITERAL_CASE, LITERAL_FINALLY,
+                    LITERAL_CATCH"/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <!-- suppression is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
+            <property name="id" value="RightCurlyAlone"/>
+            <property name="query" value="//RCURLY[parent::SLIST[count(./*)=1
+                               and not(parent::LITERAL_CATCH)]
+                               or (preceding-sibling::*[last()][self::LCURLY]
+                               and not(parent::SLIST/parent::LITERAL_CATCH))
+                               or (parent::SLIST/parent::LITERAL_CATCH
+                               and parent::SLIST/parent::LITERAL_CATCH/following-sibling::*)]"/>
+        </module>
+        <module name="WhitespaceAfter">
+            <property name="tokens"
+                      value="COMMA, SEMI, TYPECAST, ELLIPSIS, LITERAL_YIELD, LITERAL_CASE, ANNOTATIONS"/>
+        </module>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyLambdas" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+            <property name="allowEmptyLoops" value="true"/>
+            <property name="allowEmptySwitchBlockStatements" value="true"/>
+            <property name="ignoreEnhancedForColon" value="false"/>
+            <property name="tokens"
+                      value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
+                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
+                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
+                    LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
+                    NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
+                    SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT,
+                    TYPE_EXTENSION_AND, LITERAL_WHEN"/>
+            <message key="ws.notFollowed"
+                     value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks
+               may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+            <message key="ws.notPreceded"
+                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <property name="checks" value="WhitespaceAround"/>
+            <property name="query" value="//*[self::LITERAL_IF or self::LITERAL_ELSE or
+                                 self::STATIC_INIT]/SLIST[count(./*)=1]
+                                 | //*[self::STATIC_INIT or self::LITERAL_TRY or self::LITERAL_IF]
+                                 //*[self::RCURLY][parent::SLIST[count(./*)=1]]
+                                 | //SLIST[count(./*)=1][parent::LITERAL_TRY and
+                                 not(following-sibling::*)]
+                                 | //SLIST[count(./*)=1][parent::LITERAL_CATCH and
+                                 not(parent::LITERAL_CATCH/following-sibling::*)]"/>
+        </module>
+        <module name="RegexpSinglelineJava">
+            <property name="format" value="\{[ ]+\}"/>
+            <property name="message" value="Empty blocks should have no spaces. Empty blocks
+                                   may only be represented as '{}' when not part of a
+                                   multi-block statement (4.1.3)"/>
+        </module>
+        <module name="OneStatementPerLine"/>
+        <module name="MultipleVariableDeclarations"/>
+        <module name="ArrayTypeStyle"/>
+        <module name="JavadocLeadingAsteriskAlign"/>
+        <module name="JavadocMissingLeadingAsterisk"/>
+        <module name="JavadocContentLocation"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="FallThrough"/>
+        <module name="UpperEll"/>
+        <module name="ModifierOrder"/>
+        <module name="TextBlockGoogleStyleFormatting"/>
+        <module name="EmptyLineSeparator">
+            <property name="tokens"
+                      value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+            <property name="allowMultipleEmptyLines" value="false"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapDot"/>
+            <property name="tokens" value="DOT"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapComma"/>
+            <property name="tokens" value="COMMA"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/259 -->
+            <property name="id" value="SeparatorWrapEllipsis"/>
+            <property name="tokens" value="ELLIPSIS"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/258 -->
+            <property name="id" value="SeparatorWrapArrayDeclarator"/>
+            <property name="tokens" value="ARRAY_DECLARATOR"/>
+            <property name="option" value="EOL"/>
+        </module>
+        <module name="SeparatorWrap">
+            <property name="id" value="SeparatorWrapMethodRef"/>
+            <property name="tokens" value="METHOD_REF"/>
+            <property name="option" value="nl"/>
+        </module>
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+                     value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="TypeName">
+            <property name="format" value="^[A-Z][a-zA-Z0-9]*(?:[0-9](?:_[0-9]+)*)?$"/>
+            <property name="tokens" value="CLASS_DEF"/>
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="TypeName">
+            <property name="tokens" value="INTERFACE_DEF, ENUM_DEF,
+                    ANNOTATION_DEF, RECORD_DEF"/>
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MemberName">
+            <property name="format"
+                      value="^(?![a-z]$)(?![a-z][A-Z])[a-z][a-zA-Z0-9]*(?:_[0-9]+)*$"/>
+            <message key="name.invalidPattern"
+                     value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ParameterName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LambdaParameterName">
+            <property name="format" value="^(_|[a-z]([a-z0-9][a-zA-Z0-9]*)?)$"/>
+            <message key="name.invalidPattern"
+                     value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="CatchParameterName">
+            <property name="format" value="^(_|[a-z]([a-z0-9][a-zA-Z0-9]*)?)$"/>
+            <message key="name.invalidPattern"
+                     value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LocalVariableName">
+            <property name="format" value="^(_|[a-z]([a-z0-9][a-zA-Z0-9]*)?)$"/>
+            <message key="name.invalidPattern"
+                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="PatternVariableName">
+            <property name="format" value="^(_|[a-z]([a-z0-9][a-zA-Z0-9]*)?)$"/>
+            <message key="name.invalidPattern"
+                     value="Pattern variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="RecordComponentName">
+            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+            <message key="name.invalidPattern"
+                     value="Record component name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="RecordTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Record type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="InterfaceTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="NoFinalizer"/>
+        <module name="GenericWhitespace">
+            <message key="ws.followed"
+                     value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+            <message key="ws.preceded"
+                     value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+            <message key="ws.illegalFollow"
+                     value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+            <message key="ws.notPreceded"
+                     value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+        </module>
+        <module name="Indentation">
+            <property name="basicOffset" value="2"/>
+            <property name="braceAdjustment" value="2"/>
+            <property name="caseIndent" value="2"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="4"/>
+            <property name="arrayInitIndent" value="2"/>
+        </module>
+
+        <module name="AbbreviationAsWordInName">
+            <property name="ignoreFinal" value="false"/>
+            <property name="allowedAbbreviationLength" value="0"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
+                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF, PATTERN_VARIABLE_DEF, RECORD_DEF,
+                    RECORD_COMPONENT_DEF"/>
+        </module>
+        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
+        <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="ConstructorsDeclarationGrouping"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="CustomImportOrder">
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="separateLineBetweenGroups" value="true"/>
+            <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+            <property name="tokens" value="IMPORT, STATIC_IMPORT, PACKAGE_DEF"/>
+        </module>
+        <module name="MethodParamPad">
+            <property name="tokens"
+                      value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF, CTOR_CALL,
+                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF, RECORD_DEF, RECORD_PATTERN_DEF"/>
+        </module>
+        <module name="NoWhitespaceBefore">
+            <property name="tokens"
+                      value="COMMA, SEMI, POST_INC, POST_DEC, DOT,
+                    LABELED_STAT, METHOD_REF, ELLIPSIS"/>
+            <property name="allowLineBreaks" value="true"/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <property name="checks" value="NoWhitespaceBefore"/>
+            <property name="query"
+                      value="//ELLIPSIS[preceding-sibling::TYPE/ANNOTATIONS[ANNOTATION[LPAREN]
+              or not(following-sibling::*)]]"/>
+        </module>
+        <module name="ParenPad">
+            <property name="tokens"
+                      value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
+                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA,
+                    RECORD_DEF, RECORD_PATTERN_DEF"/>
+        </module>
+        <module name="OperatorWrap">
+            <property name="option" value="NL"/>
+            <property name="tokens"
+                      value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF,
+                    TYPE_EXTENSION_AND "/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationMostCases"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF,
+                      RECORD_DEF, COMPACT_CTOR_DEF, PACKAGE_DEF"/>
+        </module>
+        <module name="AnnotationLocation">
+            <property name="id" value="AnnotationLocationVariables"/>
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="allowSamelineMultipleAnnotations" value="true"/>
+        </module>
+        <module name="NonEmptyAtclauseDescription"/>
+        <module name="InvalidJavadocPosition"/>
+        <module name="JavadocTagContinuationIndentation"/>
+        <module name="SummaryJavadoc">
+            <property name="forbiddenSummaryFragments"
+                      value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )|^[a-z]"/>
+        </module>
+        <module name="JavadocParagraph">
+            <property name="allowNewlineParagraph" value="false"/>
+        </module>
+        <module name="RequireEmptyLineBeforeBlockTagGroup"/>
+        <module name="AtclauseOrder">
+            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+            <property name="target"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+        </module>
+        <module name="JavadocMethod">
+            <property name="accessModifiers" value="public"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF, COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="MissingJavadocMethod">
+            <property name="scope" value="protected"/>
+            <property name="allowMissingPropertyJavadoc" value="true"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
+            <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF,
+                                   COMPACT_CTOR_DEF"/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <property name="checks" value="MissingJavadocMethod"/>
+            <property name="query" value="//*[self::METHOD_DEF or self::CTOR_DEF
+                                 or self::ANNOTATION_FIELD_DEF or self::COMPACT_CTOR_DEF]
+                                 [ancestor::*[self::INTERFACE_DEF or self::CLASS_DEF
+                                 or self::RECORD_DEF or self::ENUM_DEF]
+                                 [not(./MODIFIERS/LITERAL_PUBLIC)]]"/>
+        </module>
+        <module name="MissingJavadocType">
+            <property name="scope" value="protected"/>
+            <property name="tokens"
+                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                      RECORD_DEF, ANNOTATION_DEF"/>
+            <property name="excludeScope" value="nothing"/>
+        </module>
+        <module name="MethodName">
+            <property name="format"
+                      value="^(?![a-z]$)(?![a-z][A-Z])[a-z][a-z0-9]*(?:[A-Z][a-z0-9]*)*(?:_[0-9]+)*$"/>
+            <message key="name.invalidPattern"
+                     value="Method name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="SuppressionXpathSingleFilter">
+            <property name="checks" value="MethodName"/>
+            <property name="query" value="//METHOD_DEF[
+                                     ./MODIFIERS/ANNOTATION//IDENT[contains(@text, 'Test')]
+                                   ]/IDENT"/>
+            <property name="message" value="'[a-z][a-z0-9][a-zA-Z0-9]*(?:_[a-z][a-z0-9][a-zA-Z0-9]*)*'"/>
+        </module>
+        <module name="SingleLineJavadoc"/>
+        <module name="TodoComment">
+            <property name="format" value="^[ \t]*(?!TODO:)(?i:TODO)\b:?"/>
+            <message key="todo.match"
+                     value="''TODO:'' must be written in all caps and followed by a colon."/>
+        </module>
+        <module name="EmptyCatchBlock">
+            <property name="commentFormat" value="\w+"/>
+        </module>
+        <module name="CommentsIndentation">
+            <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+        </module>
+        <!-- https://checkstyle.org/filters/suppressionxpathfilter.html -->
+        <module name="SuppressionXpathFilter">
+            <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+                      default="checkstyle-xpath-suppressions.xml" />
+            <property name="optional" value="true"/>
+        </module>
+        <module name="SuppressWarningsHolder" />
+        <module name="SuppressionCommentFilter">
+            <property name="offCommentFormat" value="CHECKSTYLE.OFF\: ([\w\|]+)" />
+            <property name="onCommentFormat" value="CHECKSTYLE.ON\: ([\w\|]+)" />
+            <property name="checkFormat" value="$1" />
+        </module>
+        <module name="SuppressWithNearbyCommentFilter">
+            <property name="commentFormat" value="CHECKSTYLE.SUPPRESS\: ([\w\|]+)"/>
+            <!-- $1 refers to the first match group in the regex defined in commentFormat -->
+            <property name="checkFormat" value="$1"/>
+            <!-- The check is suppressed in the next line of code after the comment -->
+            <property name="influenceFormat" value="1"/>
+        </module>
+    </module>
+</module>
@@ -0,0 +1,21 @@
+package codes.thischwa.jdvs;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+@SpringBootApplication
+@EnableScheduling
+@Slf4j
+public class JdvsApplication {
+  public static void main(String[] args) {
+
+    try {
+      SpringApplication.run(JdvsApplication.class, args);
+    } catch (Exception e) {
+      log.error("Unexpected exception, Spring Boot stops! Message: {}", e.getMessage());
+      System.exit(10);
+    }
+  }
+}
@@ -0,0 +1,29 @@
+package codes.thischwa.jdvs.config;
+
+import codes.thischwa.jdvs.model.config.JdvsConfig;
+import codes.thischwa.jdvs.jpa.GitRepositoryRepository;
+import codes.thischwa.jdvs.model.GitRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class RepoConfigLoader {
+  private final JdvsConfig jdvsConfig;
+  private final GitRepositoryRepository repository;
+
+  public void loadConfig() {
+    if (jdvsConfig.getRepositories() != null) {
+      for (JdvsConfig.RepoConfig repoCfg : jdvsConfig.getRepositories()) {
+        if (repository.findByName(repoCfg.getName()).isEmpty()) {
+          GitRepository repo = new GitRepository();
+          repo.setName(repoCfg.getName());
+          repository.save(repo);
+          log.info("Repository {} added from configuration.", repoCfg.getName());
+        }
+      }
+    }
+  }
+}
@@ -0,0 +1,9 @@
+package codes.thischwa.jdvs.jpa;
+
+import codes.thischwa.jdvs.model.GitRepository;
+import java.util.Optional;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface GitRepositoryRepository extends JpaRepository<GitRepository, Long> {
+  Optional<GitRepository> findByName(String name);
+}
@@ -0,0 +1,24 @@
+package codes.thischwa.jdvs.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import java.time.LocalDateTime;
+import lombok.Data;
+
+@Entity
+@Data
+public class GitRepository {
+  @Id
+  @GeneratedValue(strategy = GenerationType.IDENTITY)
+  private Long id;
+
+  @Column(nullable = false, unique = true)
+  private String name;
+
+  private String lastTag;
+
+  private LocalDateTime updated;
+}
@@ -0,0 +1,14 @@
+package codes.thischwa.jdvs.model.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestClient;
+
+@Configuration
+public class AppConfig {
+
+  @Bean
+  public RestClient restClient() {
+    return RestClient.create();
+  }
+}
@@ -0,0 +1,13 @@
+package codes.thischwa.jdvs.model.config;
+
+import java.util.List;
+import lombok.Data;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ConfigurationProperties(prefix = "git")
+@Data
+public class GitConfig {
+  private List<String> javadocPaths;
+}
@@ -0,0 +1,31 @@
+package codes.thischwa.jdvs.model.config;
+
+import java.util.List;
+import java.util.Objects;
+import lombok.Data;
+import org.jspecify.annotations.Nullable;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ConfigurationProperties(prefix = "jdvs")
+@Data
+public class JdvsConfig {
+  private String baseDir;
+  private boolean cleanOnStart;
+  private boolean runOnStart;
+  private String mavenCentralUrl;
+  private List<RepoConfig> repositories;
+
+  public String getEffectiveMavenRepoUrl(RepoConfig cfg) {
+    return Objects.requireNonNullElse(cfg.getMavenRepoUrl(), mavenCentralUrl);
+  }
+
+  @Data
+  public static class RepoConfig {
+    private String name;
+    private String groupId;
+    private String artifactId;
+    private String mavenRepoUrl;
+  }
+}
@@ -0,0 +1,58 @@
+package codes.thischwa.jdvs.service;
+
+import codes.thischwa.jdvs.config.RepoConfigLoader;
+import codes.thischwa.jdvs.jpa.GitRepositoryRepository;
+import codes.thischwa.jdvs.model.config.JdvsConfig;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Comparator;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class ApplicationStartupListener {
+
+  private final GitRepositoryRepository repository;
+  private final JdvsConfig jdvsConfig;
+  private final RepoConfigLoader repoConfigLoader;
+  private final UpdateScheduler updateScheduler;
+
+  @EventListener(ApplicationReadyEvent.class)
+  public void onApplicationReady() {
+    if (jdvsConfig.isCleanOnStart()) {
+      log.info("'jdvs.clean-on-start' is enabled – cleaning base directory and database.");
+      cleanBaseDir();
+      repository.deleteAll();
+    }
+    repoConfigLoader.loadConfig();
+    if (jdvsConfig.isRunOnStart()) {
+      log.info("'jdvs.run-on-start' is enabled – running initial update.");
+      updateScheduler.updateAll();
+    }
+  }
+
+  private void cleanBaseDir() {
+    Path baseDir = Path.of(jdvsConfig.getBaseDir());
+    if (!Files.exists(baseDir)) {
+      return;
+    }
+    try (var stream = Files.walk(baseDir)) {
+      stream.sorted(Comparator.reverseOrder()).forEach(path -> {
+        try {
+          Files.delete(path);
+        } catch (IOException e) {
+          log.warn("Failed to delete path: {}", path, e);
+        }
+      });
+      log.info("Deleted base directory: {}", baseDir);
+    } catch (IOException e) {
+      log.error("Failed to walk base directory: {}", baseDir, e);
+    }
+  }
+}
@@ -0,0 +1,153 @@
+package codes.thischwa.jdvs.service;
+
+import codes.thischwa.jdvs.model.config.JdvsConfig;
+import codes.thischwa.jdvs.model.config.JdvsConfig.RepoConfig;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.StringReader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.Optional;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestClient;
+import org.springframework.web.client.RestClientException;
+import org.w3c.dom.Document;
+import org.w3c.dom.NodeList;
+import org.xml.sax.InputSource;
+import org.xml.sax.SAXException;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class MavenJavadocService {
+
+  private final JdvsConfig jdvsConfig;
+  private final RestClient restClient;
+
+  public Optional<String> fetchLatestVersion(String repoName) {
+    RepoConfig cfg = findConfig(repoName);
+    String metadataUrl = baseUrl(cfg) + "/maven-metadata.xml";
+    log.info("Fetching Maven metadata from {}", metadataUrl);
+    try {
+      String xml = restClient.get().uri(metadataUrl).retrieve().body(String.class);
+      Document doc = parseXml(xml);
+      Optional<String> version = resolveVersionTag(doc);
+      if (version.isPresent()) {
+        log.info("Latest version of {} is {}", repoName, version.get());
+        return version;
+      }
+      log.warn("Could not determine latest version for {}", repoName);
+    } catch (ParserConfigurationException | SAXException | IOException e) {
+      log.error("Failed to parse Maven metadata for {}", repoName, e);
+    } catch (RestClientException e) {
+      log.error("Failed to fetch Maven metadata for {}", repoName, e);
+    }
+    return Optional.empty();
+  }
+
+  public boolean generateJavadoc(String repoName, String version) {
+    RepoConfig cfg = findConfig(repoName);
+    String resolvedVersion = version.endsWith("-SNAPSHOT")
+        ? resolveSnapshotVersion(cfg, version)
+        : version;
+    String jarUrl = baseUrl(cfg) + "/" + version + "/"
+        + cfg.getArtifactId() + "-" + resolvedVersion + "-javadoc.jar";
+    log.info("Downloading Javadoc JAR from {}", jarUrl);
+
+    Path outputDir = Path.of(jdvsConfig.getBaseDir(), "javadoc", repoName);
+    try {
+      Files.createDirectories(outputDir);
+      extractJavadocJar(jarUrl, outputDir);
+      log.info("Javadoc successfully extracted for {} to {}", repoName, outputDir);
+      return true;
+    } catch (IOException | RestClientException e) {
+      log.error("Failed to generate Javadoc for {} version {}", repoName, version, e);
+      return false;
+    }
+  }
+
+  private void extractJavadocJar(String jarUrl, Path outputDir) throws IOException {
+    byte[] jarBytes = restClient.get().uri(jarUrl).retrieve().body(byte[].class);
+    if (jarBytes == null) {
+      throw new IOException("Empty response for " + jarUrl);
+    }
+    Path safeOutputDir = outputDir.toAbsolutePath().normalize();
+    try (ZipInputStream zip = new ZipInputStream(new ByteArrayInputStream(jarBytes))) {
+      ZipEntry entry;
+      while ((entry = zip.getNextEntry()) != null) {
+        String name = entry.getName();
+        if (!entry.isDirectory() && !name.startsWith("META-INF/")) {
+          Path dest = safeOutputDir.resolve(name).normalize();
+          if (!dest.startsWith(safeOutputDir)) {
+            throw new IOException("Zip slip detected: " + name);
+          }
+          Files.createDirectories(dest.getParent());
+          Files.copy(zip, dest, StandardCopyOption.REPLACE_EXISTING);
+        }
+        zip.closeEntry();
+      }
+    }
+  }
+
+  private String resolveSnapshotVersion(RepoConfig cfg, String version) {
+    String metadataUrl = baseUrl(cfg) + "/" + version + "/maven-metadata.xml";
+    log.info("Resolving SNAPSHOT version from {}", metadataUrl);
+    try {
+      String xml = restClient.get().uri(metadataUrl).retrieve().body(String.class);
+      Document doc = parseXml(xml);
+      NodeList nodes = doc.getElementsByTagName("snapshotVersion");
+      for (int i = 0; i < nodes.getLength(); i++) {
+        org.w3c.dom.Element el = (org.w3c.dom.Element) nodes.item(i);
+        String classifier = firstText(el.getElementsByTagName("classifier"));
+        String ext = firstText(el.getElementsByTagName("extension"));
+        String value = firstText(el.getElementsByTagName("value"));
+        if ("javadoc".equals(classifier) && "jar".equals(ext) && value != null) {
+          log.info("Resolved SNAPSHOT version to {}", value);
+          return value;
+        }
+      }
+    } catch (ParserConfigurationException | SAXException | IOException e) {
+      log.warn("Could not parse SNAPSHOT metadata for {}, falling back to {}",
+          cfg.getArtifactId(), version, e);
+    } catch (RestClientException e) {
+      log.warn("Could not fetch SNAPSHOT metadata for {}, falling back to {}",
+          cfg.getArtifactId(), version, e);
+    }
+    return version;
+  }
+
+  private String baseUrl(RepoConfig cfg) {
+    String groupPath = cfg.getGroupId().replace('.', '/');
+    return jdvsConfig.getEffectiveMavenRepoUrl(cfg) + "/" + groupPath + "/" + cfg.getArtifactId();
+  }
+
+  private RepoConfig findConfig(String repoName) {
+    return jdvsConfig.getRepositories().stream()
+        .filter(r -> repoName.equals(r.getName()))
+        .findFirst()
+        .orElseThrow(() -> new IllegalArgumentException("No config found for: " + repoName));
+  }
+
+  private static Optional<String> resolveVersionTag(Document doc) {
+    return Optional.ofNullable(firstText(doc.getElementsByTagName("release")))
+        .or(() -> Optional.ofNullable(firstText(doc.getElementsByTagName("latest"))));
+  }
+
+  private static String firstText(NodeList nodes) {
+    return nodes.getLength() > 0 ? nodes.item(0).getTextContent() : null;
+  }
+
+  private static Document parseXml(String xml)
+      throws ParserConfigurationException, SAXException, IOException {
+    return DocumentBuilderFactory.newInstance()
+        .newDocumentBuilder()
+        .parse(new InputSource(new StringReader(xml)));
+  }
+}
@@ -0,0 +1,47 @@
+package codes.thischwa.jdvs.service;
+
+import codes.thischwa.jdvs.jpa.GitRepositoryRepository;
+import codes.thischwa.jdvs.model.GitRepository;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.Optional;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class UpdateScheduler {
+
+  private final GitRepositoryRepository repository;
+  private final MavenJavadocService mavenJavadocService;
+
+  @Scheduled(cron = "${jdvs.cron}")
+  public void updateAll() {
+    log.info("Starting scheduled update of repositories...");
+    List<GitRepository> repos = repository.findAll();
+    for (GitRepository repo : repos) {
+      updateRepo(repo);
+    }
+  }
+
+  private void updateRepo(GitRepository repo) {
+    log.info("Checking repository: {}", repo.getName());
+    Optional<String> latestVersion = mavenJavadocService.fetchLatestVersion(repo.getName());
+    if (latestVersion.isPresent()) {
+      String version = latestVersion.get();
+      if (!version.equals(repo.getLastTag())) {
+        log.info("New version {} found for {}. Generating Javadoc...", version, repo.getName());
+        if (mavenJavadocService.generateJavadoc(repo.getName(), version)) {
+          repo.setLastTag(version);
+          repo.setUpdated(LocalDateTime.now());
+          repository.save(repo);
+        }
+      } else {
+        log.info("Repository {} is already up to date ({}).", repo.getName(), version);
+      }
+    }
+  }
+}
@@ -0,0 +1,34 @@
+package codes.thischwa.jdvs.web;
+
+import codes.thischwa.jdvs.jpa.GitRepositoryRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.server.ResponseStatusException;
+
+@Controller
+@RequiredArgsConstructor
+public class BadgeController {
+
+  private static final String BADGE_URL_PREFIX =
+      "https://img.shields.io/badge/javadoc%40JdVS-";
+
+  private static final String BADGE_URL_SUFFIX = "-green";
+
+  private final GitRepositoryRepository repository;
+
+  @GetMapping("/badge/{repositoryName}")
+  public String badge(@PathVariable String repositoryName) {
+    String tag =
+        repository
+            .findByName(repositoryName)
+            .map(r -> r.getLastTag() != null ? r.getLastTag() : "unknown")
+            .orElseThrow(
+                () ->
+                    new ResponseStatusException(
+                        HttpStatus.NOT_FOUND, "Repository not found: " + repositoryName));
+    return "redirect:" + BADGE_URL_PREFIX + tag + BADGE_URL_SUFFIX;
+  }
+}
@@ -0,0 +1,16 @@
+package codes.thischwa.jdvs.web;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * Controller for favicon.ico, just for reducing 404 errors in the logs.
+ */
+@RestController
+public class FaviconController {
+
+  @GetMapping("favicon.ico")
+  void returnNoFavicon() {
+    // see class comment
+  }
+}
@@ -0,0 +1,19 @@
+package codes.thischwa.jdvs.web;
+
+import codes.thischwa.jdvs.jpa.GitRepositoryRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@Controller
+@RequiredArgsConstructor
+public class UiController {
+  private final GitRepositoryRepository repository;
+
+  @GetMapping("/")
+  public String index(Model model) {
+    model.addAttribute("repos", repository.findAll());
+    return "index";
+  }
+}
@@ -0,0 +1,24 @@
+package codes.thischwa.jdvs.web;
+
+import codes.thischwa.jdvs.model.config.JdvsConfig;
+import java.nio.file.Path;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+@RequiredArgsConstructor
+public class WebConfig implements WebMvcConfigurer {
+  private final JdvsConfig jdvsConfig;
+
+  @Override
+  public void addResourceHandlers(ResourceHandlerRegistry registry) {
+    String javadocPath = Path.of(jdvsConfig.getBaseDir(), "javadoc").toAbsolutePath().toUri().toString();
+    if (!javadocPath.endsWith("/")) {
+      javadocPath += "/";
+    }
+    registry.addResourceHandler("/**")
+        .addResourceLocations(javadocPath);
+  }
+}
@@ -0,0 +1,27 @@
+jdvs:
+  base-dir: ./javadoc-storage
+  cron: 0 0/30 * * * ?
+  clean-on-start: false
+  run-on-start: false
+  maven-central-url: https://repo1.maven.org/maven2
+
+git:
+  javadoc-paths:
+    - target/reports/apidocs
+    - target/apidocs
+    - target/site/apidocs
+
+## import of the individual configuration settings
+spring:
+  config:
+    import: optional:file:./jdvs.yml
+
+  datasource:
+    url: jdbc:h2:file:./database/jdvsdb
+    driverClassName: org.h2.Driver
+    username: sa
+    password: ""
+  jpa:
+    database-platform: org.hibernate.dialect.H2Dialect
+    hibernate:
+      ddl-auto: none
@@ -0,0 +1,11 @@
+
+   ___     _ _   _ _____
+  |_  |   | | | | /  ___|
+    | | __| | | | \ `--.
+    | |/ _` | | | |`--. \
+/\__/ / (_| \ \_/ /\__/ /
+\____/ \__,_|\___/\____/
+
+Version: ${application.version}
+:: Spring Boot${spring-boot.formatted-version} ::
+running on java ${java.version}
@@ -0,0 +1,27 @@
+databaseChangeLog:
+  - changeSet:
+      id: 1
+      author: th-schwarz
+      changes:
+        - createTable:
+            tableName: git_repository
+            columns:
+              - column:
+                  name: id
+                  type: BIGINT
+                  autoIncrement: true
+                  constraints:
+                    primaryKey: true
+                    nullable: false
+              - column:
+                  name: name
+                  type: VARCHAR(255)
+                  constraints:
+                    nullable: false
+                    unique: true
+              - column:
+                  name: last_tag
+                  type: VARCHAR(255)
+              - column:
+                  name: updated
+                  type: TIMESTAMP
@@ -0,0 +1,3 @@
+databaseChangeLog:
+  - include:
+      file: db/changelog/001-init-schema.yaml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration debug="true">
+
+    <appender name="current"
+              class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%t] %-5level %logger{50} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.apache.http" level="info"/>
+    <logger name="org.springframework.boot.autoconfigure.logging" level="info"/>
+    <logger name="org.springframework.context" level="info"/>
+    <logger name="org.eclipse.jgit" level="info"/>
+    <logger name="com.zaxxer.hikari" level="info"/>
+
+    <root level="debug">
+        <appender-ref ref="current"/>
+    </root>
+
+</configuration>
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html xmlns:th="http://www.thymeleaf.org">
+<head>
+    <title>Javadoc Viewer Service</title>
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css">
+</head>
+<body>
+<div class="container mt-5">
+    <h1>Project Javadoc Overview</h1>
+    <table class="table table-striped">
+        <thead>
+        <tr>
+            <th>Name</th>
+            <th>Latest Version</th>
+            <th>Last Update</th>
+            <th>Javadoc link</th>
+        </tr>
+        </thead>
+        <tbody>
+        <tr th:each="repo : ${repos}">
+            <td th:text="${repo.name}">Project</td>
+            <td th:text="${repo.lastTag}">-</td>
+            <td th:text="${#temporals.format(repo.updated, 'dd.MM.yyyy HH:mm')}">-</td>
+            <td>
+                <a th:if="${repo.lastTag != null}" th:href="@{/{name}/index.html(name=${repo.name})}">
+                    <img th:src="@{/badge/{name}(name=${repo.name})}" alt="javadoc badge">
+                </a>
+                <span th:if="${repo.lastTag == null}" class="badge bg-secondary">Not yet generated</span>
+            </td>
+        </tr>
+        </tbody>
+    </table>
+</div>
+</body>
+</html>