Add RedirectFilter with configurable 301/302 rules

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: Java CI with Maven
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Get Java Version
+        run: |
+          JAVA_VERSION=$(mvn help:evaluate "-Dexpression=maven.compiler.release" -q -DforceStdout)
+          echo "JAVA_VERSION=$JAVA_VERSION" >> $GITHUB_ENV
+
+      - name: Set up JDK ${{ env.JAVA_VERSION }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ env.JAVA_VERSION }}
+          distribution: 'temurin'
+          cache: maven
+
+      - name: Compile with Maven
+        run: mvn -B compile --file pom.xml
+
+      - name: Test with Maven
+        run: mvn -B test --file pom.xml

.github/workflows/release.yml

@@ -0,0 +1,35 @@
+name: Publish Docker Image to Github Packages on Release
+on:
+  release:
+    types:
+      - published
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v6.0.2
+      - uses: docker/setup-qemu-action@v3.7.0
+      - uses: docker/setup-buildx-action@v3.12.0
+      - name: Log in to GHCR
+        uses: docker/login-action@v3.7.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5.10.0
+        with:
+          images: ghcr.io/ithsjava25/webserver
+      - name: Build and push
+        uses: docker/build-push-action@v6.18.0
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64, linux/arm64
+          tags:  ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+

pom.xml

@@ -9,12 +9,13 @@
     <version>1.0-SNAPSHOT</version>
 
     <properties>
-        <maven.compiler.release>23</maven.compiler.release>
+        <maven.compiler.release>25</maven.compiler.release>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <junit.jupiter.version>6.0.2</junit.jupiter.version>
+        <junit.jupiter.version>5.11.4</junit.jupiter.version>
         <assertj.core.version>3.27.7</assertj.core.version>
         <mockito.version>5.21.0</mockito.version>
     </properties>
+
     <dependencies>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
@@ -28,12 +29,24 @@
             <version>${assertj.core.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>${mockito.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-junit-jupiter</artifactId>
             <version>${mockito.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>4.3.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>
@@ -63,24 +76,24 @@
                 <version>3.4.0</version>
             </plugin>
             <plugin>
-                 <groupId>org.apache.maven.plugins</groupId>
-                 <artifactId>maven-dependency-plugin</artifactId>
-                 <version>3.9.0</version>
-                 <executions>
-                     <execution>
-                         <goals>
-                             <goal>properties</goal>
-                         </goals>
-                     </execution>
-                 </executions>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <version>3.9.0</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>properties</goal>
+                        </goals>
+                    </execution>
+                </executions>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>3.5.4</version>
-                 <configuration>
-                     <argLine>@{argLine} -javaagent:${org.mockito:mockito-core:jar} -Xshare:off</argLine>
-                 </configuration>
+                <configuration>
+                    <argLine>@{argLine} -javaagent:${org.mockito:mockito-core:jar} -Xshare:off</argLine>
+                </configuration>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -118,6 +131,27 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>com.diffplug.spotless</groupId>
+                <artifactId>spotless-maven-plugin</artifactId>
+                <version>3.2.1</version>
+                <configuration>
+                    <java>
+                        <removeUnusedImports/>
+                        <formatAnnotations/>
+                    </java>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>verify</phase>
+                        <goals>
+                            <goal>
+                                check
+                            </goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 </project>

src/main/java/org/example/App.java

@@ -2,6 +2,6 @@
 
 public class App {
     public static void main(String[] args) {
-        System.out.println("Hello There!");
+        new TcpServer(8080).start();
     }
-}
+}

src/main/java/org/example/TcpServer.java

@@ -0,0 +1,28 @@
+package org.example;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class TcpServer {
+
+    private final int port;
+
+    public TcpServer(int port) {
+        this.port = port;
+    }
+
+    public void start() {
+        System.out.println("Starting TCP server on port " + port);
+
+        try (ServerSocket serverSocket = new ServerSocket(port)) {
+            while (true) {
+                Socket clientSocket = serverSocket.accept(); // block
+                System.out.println("Client connected: " + clientSocket.getRemoteSocketAddress());
+                clientSocket.close();
+            }
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to start TCP server", e);
+        }
+    }
+}

src/main/java/org/example/server/FilterChain.java

@@ -0,0 +1,24 @@
+package org.example.server;
+
+import java.util.Objects;
+
+public final class FilterChain {
+
+    private final HttpFilter[] filters;
+    private final TerminalHandler terminal;
+    private int index = 0;
+
+    public FilterChain(HttpFilter[] filters, TerminalHandler terminal) {
+        this.filters = Objects.requireNonNull(filters, "filters");
+        this.terminal = Objects.requireNonNull(terminal, "terminal");
+    }
+
+    public void doFilter(HttpRequest request, HttpResponse response) {
+        if (index < filters.length) {
+            HttpFilter current = filters[index++];
+            current.doFilter(request, response, this);
+            return;
+        }
+        terminal.handle(request, response);
+    }
+}

src/main/java/org/example/server/HttpFilter.java

@@ -0,0 +1,6 @@
+package org.example.server;
+
+@FunctionalInterface
+public interface HttpFilter {
+    void doFilter(HttpRequest request, HttpResponse response, FilterChain chain);
+}

src/main/java/org/example/server/HttpRequest.java

@@ -0,0 +1,21 @@
+package org.example.server;
+
+import java.util.Objects;
+
+public final class HttpRequest {
+    private final String method;
+    private final String path;
+
+    public HttpRequest(String method, String path) {
+        this.method = Objects.requireNonNull(method, "method");
+        this.path = Objects.requireNonNull(path, "path");
+    }
+
+    public String method() {
+        return method;
+    }
+
+    public String path() {
+        return path;
+    }
+}

src/main/java/org/example/server/HttpResponse.java

@@ -0,0 +1,26 @@
+package org.example.server;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public final class HttpResponse {
+    private int status = 200;
+    private final Map<String, String> headers = new LinkedHashMap<>();
+
+    public int status() {
+        return status;
+    }
+
+    public void setStatus(int status) {
+        this.status = status;
+    }
+
+    public Map<String, String> headers() {
+        return Collections.unmodifiableMap(headers);
+    }
+
+    public void setHeader(String name, String value) {
+        headers.put(name, value);
+    }
+}

src/main/java/org/example/server/RedirectFilter.java

@@ -0,0 +1,30 @@
+package org.example.server;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.logging.Logger;
+
+public final class RedirectFilter implements HttpFilter {
+    private static final Logger LOG = Logger.getLogger(RedirectFilter.class.getName());
+    private final List<RedirectRule> rules;
+
+    public RedirectFilter(List<RedirectRule> rules) {
+        this.rules = List.copyOf(Objects.requireNonNull(rules, "rules"));
+    }
+
+    @Override
+    public void doFilter(HttpRequest request, HttpResponse response, FilterChain chain) {
+        String path = request.path();
+
+        for (RedirectRule rule : rules) {
+            if (rule.matches(path)) {
+                LOG.info(() -> "Redirecting " + path + " -> " + rule.getTargetUrl() + " (" + rule.getStatusCode() + ")");
+                response.setStatus(rule.getStatusCode());
+                response.setHeader("Location", rule.getTargetUrl());
+                return; // STOP pipeline
+            }
+        }
+
+        chain.doFilter(request, response);
+    }
+}

src/main/java/org/example/server/RedirectRule.java

@@ -0,0 +1,37 @@
+package org.example.server;
+
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+public final class RedirectRule {
+    private final Pattern sourcePattern;
+    private final String targetUrl;
+    private final int statusCode;
+
+    public RedirectRule(Pattern sourcePattern, String targetUrl, int statusCode) {
+        this.sourcePattern = Objects.requireNonNull(sourcePattern, "sourcePattern");
+        this.targetUrl = Objects.requireNonNull(targetUrl, "targetUrl");
+        if (statusCode != 301 && statusCode != 302) {
+            throw new IllegalArgumentException("statusCode must be 301 or 302");
+        }
+        this.statusCode = statusCode;
+    }
+
+    public Pattern getSourcePattern() { return sourcePattern; }
+    public String getTargetUrl() { return targetUrl; }
+    public int getStatusCode() { return statusCode; }
+
+    public boolean matches(String requestPath) {
+        return sourcePattern.matcher(requestPath).matches();
+    }
+
+    @Override
+    public String toString() {
+        return "RedirectRule{" +
+                "sourcePattern=" + sourcePattern +
+                ", targetUrl='" + targetUrl + '\'' +
+                ", statusCode=" + statusCode +
+                '}';
+    }
+}
+