Make Classworld setup more alike to vanilla Maven

Instead of providing a custom URLClassLoader, create the ClassWorld using the plexus configurator and then pass it down the call chain. This improves compatbility with any extensions or plugins that assume that their ClassLoader is a ClassRealm.
apache · Jan 31, 2023 · 237e851 · 237e851
1 parent 11c6567
commit 237e851
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Showing 6 changed files with 63 additions and 65 deletions.
diff --git a/client/src/main/java/org/mvndaemon/mvnd/client/DaemonConnector.java b/client/src/main/java/org/mvndaemon/mvnd/client/DaemonConnector.java
@@ -339,22 +339,34 @@ private Process startDaemonProcess(String daemonId, ClientOutput output) {
         final Path mvndHome = parameters.mvndHome();
         final Path workingDir = parameters.userDir();
         String command = "";
-        try (DirectoryStream<Path> jarPaths =
-                Files.newDirectoryStream(mvndHome.resolve("lib").resolve("ext"))) {
+        try {
             List<String> args = new ArrayList<>();
             // executable
             final String java = Os.current().isUnixLike() ? "bin/java" : "bin\\java.exe";
             args.add(parameters.javaHome().resolve(java).toString());
             // classpath
             String mvndCommonPath = null;
             String mvndAgentPath = null;
-            for (Path jar : jarPaths) {
-                String s = jar.getFileName().toString();
-                if (s.endsWith(".jar")) {
-                    if (s.startsWith("mvnd-common-")) {
-                        mvndCommonPath = jar.toString();
-                    } else if (s.startsWith("mvnd-agent-")) {
-                        mvndAgentPath = jar.toString();
+            String plexusClassworldsPath = null;
+            try (DirectoryStream<Path> jarPaths = Files.newDirectoryStream(mvndHome.resolve("lib/ext"))) {
+                for (Path jar : jarPaths) {
+                    String s = jar.getFileName().toString();
+                    if (s.endsWith(".jar")) {
+                        if (s.startsWith("mvnd-common-")) {
+                            mvndCommonPath = jar.toString();
+                        } else if (s.startsWith("mvnd-agent-")) {
+                            mvndAgentPath = jar.toString();
+                        }
+                    }
+                }
+            }
+            try (DirectoryStream<Path> jarPaths = Files.newDirectoryStream(mvndHome.resolve("boot"))) {
+                for (Path jar : jarPaths) {
+                    String s = jar.getFileName().toString();
+                    if (s.endsWith(".jar")) {
+                        if (s.startsWith("plexus-classworlds-")) {
+                            plexusClassworldsPath = jar.toString();
+                        }
                     }
                 }
             }
@@ -364,8 +376,11 @@ private Process startDaemonProcess(String daemonId, ClientOutput output) {
             if (mvndAgentPath == null) {
                 throw new IllegalStateException("Could not find mvnd-agent jar in lib/");
             }
+            if (plexusClassworldsPath == null) {
+                throw new IllegalStateException("Could not find plexus-classworlds jar in boot/");
+            }
             args.add("-classpath");
-            args.add(mvndCommonPath + File.pathSeparator + mvndAgentPath);
+            args.add(mvndCommonPath + File.pathSeparator + plexusClassworldsPath + File.pathSeparator + mvndAgentPath);
             args.add("-javaagent:" + mvndAgentPath);
             // debug options
             if (parameters.property(Environment.MVND_DEBUG).asBoolean()) {

diff --git a/common/pom.xml b/common/pom.xml
@@ -40,6 +40,11 @@
       <groupId>org.jline</groupId>
       <artifactId>jline-terminal-jansi</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-classworlds</artifactId>
+      <scope>provided</scope>
+    </dependency>
 
     <dependency>
       <groupId>org.slf4j</groupId>

diff --git a/common/src/main/java/org/mvndaemon/mvnd/common/MavenDaemon.java b/common/src/main/java/org/mvndaemon/mvnd/common/MavenDaemon.java
@@ -18,67 +18,39 @@
  */
 package org.mvndaemon.mvnd.common;
 
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.net.URLClassLoader;
+import java.io.InputStream;
+import java.lang.reflect.Constructor;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.stream.Stream;
+
+import org.codehaus.plexus.classworlds.ClassWorld;
+import org.codehaus.plexus.classworlds.launcher.Launcher;
+import org.codehaus.plexus.classworlds.realm.ClassRealm;
 
 public class MavenDaemon {
 
     public static void main(String[] args) throws Exception {
-        final Path mvndHome = Environment.MVND_HOME.asPath();
-        URL[] classpath = Stream.concat(
-                        /* jars */
-                        Stream.of("lib/ext", "lib", "boot")
-                                .map(mvndHome::resolve)
-                                .flatMap((Path p) -> {
-                                    try {
-                                        return Files.list(p);
-                                    } catch (java.io.IOException e) {
-                                        throw new RuntimeException("Could not list " + p, e);
-                                    }
-                                })
-                                .filter(p -> {
-                                    final String fileName = p.getFileName().toString();
-                                    return fileName.endsWith(".jar") && !fileName.startsWith("mvnd-client-");
-                                })
-                                .filter(Files::isRegularFile),
-                        /* resources */
-                        Stream.of(mvndHome.resolve("conf"), mvndHome.resolve("conf/logging")))
-                .map(Path::normalize)
-                .map(Path::toUri)
-                .map(uri -> {
-                    try {
-                        return uri.toURL();
-                    } catch (MalformedURLException e) {
-                        throw new RuntimeException(e);
-                    }
-                })
-                .toArray(URL[]::new);
-        ClassLoader loader = new URLClassLoader(classpath, null) {
+        Path mvndHome = Environment.MVND_HOME.asPath();
+        Launcher launcher = new Launcher();
+        launcher.setSystemClassLoader(new ClassLoader(ClassLoader.getPlatformClassLoader()) {
+
             @Override
             protected Class<?> findClass(String name) throws ClassNotFoundException {
-                try {
-                    return super.findClass(name);
-                } catch (ClassNotFoundException e) {
+                if (name.startsWith("org.codehaus.plexus.classworlds.")
+                        || name.startsWith("org.codehaus.classworlds.")) {
                     return MavenDaemon.class.getClassLoader().loadClass(name);
                 }
+                throw new ClassNotFoundException(name);
             }
-
-            @Override
-            public URL getResource(String name) {
-                URL url = super.getResource(name);
-                if (url == null) {
-                    url = MavenDaemon.class.getClassLoader().getResource(name);
-                }
-                return url;
-            }
-        };
-        Thread.currentThread().setContextClassLoader(loader);
-        Class<?> clazz = loader.loadClass("org.mvndaemon.mvnd.daemon.Server");
-        try (AutoCloseable server = (AutoCloseable) clazz.getConstructor().newInstance()) {
+        });
+        try (InputStream in = Files.newInputStream(mvndHome.resolve("bin/m2.conf"))) {
+            launcher.configure(in);
+        }
+        ClassWorld world = launcher.getWorld();
+        ClassRealm coreRealm = launcher.getMainRealm();
+        Class<?> serverClass = coreRealm.loadClass("org.mvndaemon.mvnd.daemon.Server");
+        Constructor<?> serverConstructor = serverClass.getConstructor(ClassWorld.class);
+        try (AutoCloseable server = (AutoCloseable) serverConstructor.newInstance(world)) {
             ((Runnable) server).run();
         }
     }

diff --git a/daemon/src/main/java/org/apache/maven/cli/DaemonMavenCli.java b/daemon/src/main/java/org/apache/maven/cli/DaemonMavenCli.java
@@ -174,13 +174,12 @@ public class DaemonMavenCli {
      */
     private BuildEventListener buildEventListener = BuildEventListener.dummy();
 
-    public DaemonMavenCli() throws Exception {
+    public DaemonMavenCli(ClassWorld classWorld) throws Exception {
         slf4jLoggerFactory = LoggerFactory.getILoggerFactory();
         slf4jLogger = slf4jLoggerFactory.getLogger(this.getClass().getName());
         plexusLoggerManager = new Slf4jLoggerManager();
 
-        ClassLoader cl = Thread.currentThread().getContextClassLoader();
-        classWorld = new ClassWorld("plexus.core", cl);
+        this.classWorld = classWorld;
 
         container = container();
 
@@ -473,6 +472,7 @@ DefaultPlexusContainer container() throws Exception {
 
         List<File> extClassPath = Stream.of(
                         Environment.MVND_EXT_CLASSPATH.asString().split(","))
+                .filter(s -> s != null && !s.isEmpty())
                 .map(File::new)
                 .collect(Collectors.toList());
 

diff --git a/daemon/src/main/java/org/mvndaemon/mvnd/daemon/Server.java b/daemon/src/main/java/org/mvndaemon/mvnd/daemon/Server.java
@@ -51,6 +51,7 @@
 import java.util.stream.Collectors;
 
 import org.apache.maven.cli.DaemonMavenCli;
+import org.codehaus.plexus.classworlds.ClassWorld;
 import org.mvndaemon.mvnd.builder.SmartBuilder;
 import org.mvndaemon.mvnd.common.DaemonConnection;
 import org.mvndaemon.mvnd.common.DaemonException;
@@ -99,7 +100,7 @@ public class Server implements AutoCloseable, Runnable {
     private final DaemonMemoryStatus memoryStatus;
     private final long keepAliveMs;
 
-    public Server() throws IOException {
+    public Server(ClassWorld world) throws IOException {
         // When spawning a new process, the child process is create within
         // the same process group.  This means that a few signals are sent
         // to the whole group.  This is the case for SIGINT (Ctrl-C) and
@@ -123,7 +124,7 @@ public Server() throws IOException {
                 .orElse(SocketFamily.inet);
 
         try {
-            cli = new DaemonMavenCli();
+            cli = new DaemonMavenCli(world);
             registry = new DaemonRegistry(Environment.MVND_REGISTRY.asPath());
             socket = socketFamily.openServerSocket();
             executor = Executors.newScheduledThreadPool(1);

diff --git a/pom.xml b/pom.xml
@@ -320,6 +320,11 @@
           </exclusion>
         </exclusions>
       </dependency>
+      <dependency>
+        <groupId>org.codehaus.plexus</groupId>
+        <artifactId>plexus-classworlds</artifactId>
+        <version>2.6.0</version>
+      </dependency>
 
     </dependencies>
   </dependencyManagement>