Adding org.eclipse.jetty.server.handler.PathMappingsHandler example

embedded/path-mapping-handler/extras/extra.css

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+table { font-family: sans-serif; }

embedded/path-mapping-handler/pom.xml

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+<?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/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.eclipse.jetty.examples.embedded</groupId>
+    <artifactId>jetty-embedded-examples</artifactId>
+    <version>12.0.x</version>
+  </parent>
+  <artifactId>path-mapping-handler</artifactId>
+  <version>12.0.x</version>
+  <packaging>jar</packaging>
+  <name>Jetty Examples :: Jetty 12.0.x :: Embedded :: Path Mapping Handler</name>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.eclipse.jetty</groupId>
+      <artifactId>jetty-server</artifactId>
+      <version>${jetty.version}</version>
+    </dependency>
+
+    <dependency>
+      <groupId>org.eclipse.jetty</groupId>
+      <artifactId>jetty-slf4j-impl</artifactId>
+      <version>${jetty.version}</version>
+    </dependency>
+
+    <dependency>
+      <groupId>org.webjars</groupId>
+      <artifactId>bootstrap</artifactId>
+      <version>5.3.2</version>
+    </dependency>
+
+    <dependency>
+      <groupId>org.eclipse.jetty.toolchain</groupId>
+      <artifactId>jetty-test-helper</artifactId>
+      <version>${jetty-test-helper.version}</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+</project>

embedded/path-mapping-handler/src/main/java/examples/HelloHandler.java

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+package examples;//
+// ========================================================================
+// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
+import java.nio.charset.StandardCharsets;
+
+import org.eclipse.jetty.http.HttpHeader;
+import org.eclipse.jetty.server.Handler;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.Response;
+import org.eclipse.jetty.util.BufferUtil;
+import org.eclipse.jetty.util.Callback;
+
+public class HelloHandler extends Handler.Abstract
+{
+    private final String msg;
+
+    public HelloHandler(String msg)
+    {
+        this.msg = msg;
+    }
+
+    @Override
+    public boolean handle(Request request, Response response, Callback callback) throws Exception
+    {
+        response.getHeaders().put(HttpHeader.CONTENT_TYPE, "text/plain; charset=utf-8");
+        response.write(true, BufferUtil.toBuffer(String.format("%s%n", msg), StandardCharsets.UTF_8), callback);
+        return true;
+    }
+}

embedded/path-mapping-handler/src/main/java/examples/PathMappingServer.java

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+//
+// ========================================================================
+// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
+package examples;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.function.Function;
+
+import org.eclipse.jetty.http.HttpURI;
+import org.eclipse.jetty.http.pathmap.PathSpec;
+import org.eclipse.jetty.server.Handler;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.Response;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.handler.PathMappingsHandler;
+import org.eclipse.jetty.server.handler.ResourceHandler;
+import org.eclipse.jetty.util.Callback;
+import org.eclipse.jetty.util.resource.Resource;
+import org.eclipse.jetty.util.resource.ResourceFactory;
+import org.eclipse.jetty.util.resource.Resources;
+
+public class PathMappingServer
+{
+    public static void main(String[] args) throws Exception
+    {
+        Server server = PathMappingServer.newServer(8080);
+        server.start();
+        server.join();
+    }
+
+    public static Server newServer(int port) throws IOException
+    {
+        Server server = new Server(port);
+
+        ResourceFactory resourceFactory = ResourceFactory.of(server);
+
+        PathMappingsHandler pathMappingsHandler = new PathMappingsHandler();
+
+        Resource rootResourceDir = resourceFactory.newClassLoaderResource("/static-root/");
+        if (!Resources.isReadableDirectory(rootResourceDir))
+            throw new FileNotFoundException("Unable to find /static-root/ classloader directory");
+
+        ResourceHandler rootResourceHandler = new ResourceHandler();
+        rootResourceHandler.setBaseResource(rootResourceDir);
+        rootResourceHandler.setDirAllowed(false);
+        rootResourceHandler.setWelcomeFiles("index.html");
+
+        Path extrasDir = Path.of("extras").toAbsolutePath();
+        if (!Files.isDirectory(extrasDir))
+            throw new FileNotFoundException("Unable to find /extras/ directory on disk: " + extrasDir);
+        if (!Files.isReadable(extrasDir))
+            throw new FileNotFoundException("Unable to read directory (permissions?): " + extrasDir);
+
+        Resource extraResourceDir = resourceFactory.newResource(extrasDir);
+
+        ResourceHandler extraResourceHandler = new ResourceHandler();
+        extraResourceHandler.setBaseResource(extraResourceDir);
+        extraResourceHandler.setDirAllowed(true);
+
+        Resource metaInfResource = findMetaInfResources(resourceFactory, PathMappingServer.class.getClassLoader());
+
+        ResourceHandler metaInfResourceHandler = new ResourceHandler();
+        metaInfResourceHandler.setBaseResource(metaInfResource);
+        metaInfResourceHandler.setDirAllowed(false);
+
+        // The context-path is the portion of the path that doesn't belong to the filename.
+        // Example:
+        //   You have this setup.
+        //   * You have files you want to serve in "/home/user/webroot/"
+        //   * You have that directory mapped against the path-spec of "/content/*"
+        //
+        //   Then a request arrives against the path "/content/foo.txt"
+        //   The server will send that request to the mapped location of "/content/*"
+        //   which is your ResourceHandler serving content from "/home/user/webroot/"
+        //   The looked for file will be <base-dir> + "/" + <request-path>
+        //   which turns out to be "/home/user/webroot/content/foo.txt"
+        //
+        //   The PathNameWrapper below allows you to map the incoming request path
+        //   to a simple path name that the ResourceHandler of your choice can use
+        //   against it's base resource.
+
+        pathMappingsHandler.addMapping(PathSpec.from("/"), rootResourceHandler);
+        pathMappingsHandler.addMapping(PathSpec.from("/extras/*"),
+            new StripContextPath("/extras", extraResourceHandler));
+        pathMappingsHandler.addMapping(PathSpec.from("/jars/*"),
+            new StripContextPath("/jars", metaInfResourceHandler));
+        // Example of a mapping to an extension.
+        pathMappingsHandler.addMapping(PathSpec.from("*.png"),
+            new PathNameWrapper((path) ->
+            {
+                int idx = path.lastIndexOf("/");
+                if (idx >= 0)
+                    return "/images" + path.substring(idx);
+                return "/images/" + path;
+            }, extraResourceHandler));
+        pathMappingsHandler.addMapping(PathSpec.from("/hello/*"), new HelloHandler("Mappings"));
+
+        server.setHandler(pathMappingsHandler);
+        return server;
+    }
+
+    private static Resource findMetaInfResources(ResourceFactory resourceFactory, ClassLoader classLoader) throws IOException
+    {
+        List<URL> hits = Collections.list(classLoader.getResources("META-INF/resources"));
+        List<Resource> resources = new ArrayList<>();
+        for (URL hit : hits)
+        {
+            Resource resource = resourceFactory.newResource(hit);
+            if (Resources.isReadableDirectory(resource))
+                resources.add(resource);
+        }
+
+        if (resources.isEmpty())
+            throw new FileNotFoundException("Classloader Configuration error: No META-INF/resources entries found");
+
+        return ResourceFactory.combine(resources);
+    }
+
+    private static class StripContextPath extends PathNameWrapper
+    {
+        public StripContextPath(String contextPath, Handler handler)
+        {
+            super((path) ->
+            {
+                if (path.startsWith(contextPath))
+                    return path.substring(contextPath.length());
+                return path;
+            }, handler);
+        }
+    }
+
+    private static class PathNameWrapper extends Handler.Wrapper
+    {
+        private final Function<String, String> nameFunction;
+
+        public PathNameWrapper(Function<String, String> nameFunction, Handler handler)
+        {
+            super(handler);
+            this.nameFunction = nameFunction;
+        }
+
+        @Override
+        public boolean handle(Request request, Response response, Callback callback) throws Exception
+        {
+            String originalPath = request.getHttpURI().getPath();
+
+            String newPath = nameFunction.apply(originalPath);
+
+            HttpURI newURI = HttpURI.build(request.getHttpURI()).path(newPath);
+
+            Request wrappedRequest = new Request.Wrapper(request)
+            {
+                @Override
+                public HttpURI getHttpURI()
+                {
+                    return newURI;
+                }
+            };
+
+            return super.handle(wrappedRequest, response, callback);
+        }
+    }
+}

embedded/path-mapping-handler/src/main/resources/jetty-logging.properties

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+org.eclipse.jetty.LEVEL=INFO

embedded/path-mapping-handler/src/main/resources/static-root/hello.html

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+<html>
+<head>
+<title>Hello from /static-root/</title>
+</head>
+<body>
+<h4>Hello from <code>/static-root/</code></h4>
+</body>
+</html>

embedded/path-mapping-handler/src/main/resources/static-root/index.html

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+<html>
+<head>
+    <title>Showing index.html from root</title>
+</head>
+<body>
+<h4>This is the index.html from /static-root/</h4>
+</body>
+</html>