Merge remote-tracking branch 'origin/jetty-12.1.x' into fix/12.1.x/un…

…ify-deploy

jetty-core/jetty-ee/pom.xml

@@ -54,6 +54,10 @@
         <artifactId>maven-surefire-plugin</artifactId>
         <configuration>
           <argLine>@{argLine} ${jetty.surefire.argLine} --add-reads org.eclipse.jetty.ee=org.eclipse.jetty.logging</argLine>
+          <excludes>
+            <!-- This class modifies internal JVM statics, and causes problems in parallel testing -->
+            <exclude>org.eclipse.jetty.ee.WebAppClassLoaderUrlStreamTest</exclude>
+          </excludes>
         </configuration>
       </plugin>
     </plugins>

jetty-core/jetty-ee/src/main/java/module-info.java

@@ -17,6 +17,7 @@
 
     requires transitive org.eclipse.jetty.util;
     requires transitive org.eclipse.jetty.server;
+    requires java.instrument;
 
     exports org.eclipse.jetty.ee;
 }

jetty-core/jetty-ee/src/main/java/org/eclipse/jetty/ee/CachingWebAppClassLoader.java

@@ -0,0 +1,120 @@
+//
+// ========================================================================
+// 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 org.eclipse.jetty.ee;
+
+import java.io.IOException;
+import java.net.URL;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.eclipse.jetty.util.annotation.ManagedObject;
+import org.eclipse.jetty.util.annotation.ManagedOperation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A WebAppClassLoader that caches {@link #getResource(String)} results.
+ * Specifically this ClassLoader caches not found classes and resources,
+ * which can greatly increase performance for applications that search
+ * for resources.
+ */
+@ManagedObject
+public class CachingWebAppClassLoader extends WebAppClassLoader
+{
+    private static final Logger LOG = LoggerFactory.getLogger(CachingWebAppClassLoader.class);
+
+    private final Set<String> _notFound = ConcurrentHashMap.newKeySet();
+    private final ConcurrentHashMap<String, URL> _cache = new ConcurrentHashMap<>();
+
+    public CachingWebAppClassLoader(ClassLoader parent, Context context) throws IOException
+    {
+        super(parent, context);
+    }
+
+    public CachingWebAppClassLoader(Context context) throws IOException
+    {
+        super(context);
+    }
+
+    @Override
+    public URL getResource(String name)
+    {
+        if (_notFound.contains(name))
+        {
+            if (LOG.isDebugEnabled())
+                LOG.debug("Not found cache hit resource {}", name);
+            return null;
+        }
+
+        URL url = _cache.get(name);
+
+        if (url == null)
+        {
+            // Not found in cache, try parent
+            url = super.getResource(name);
+
+            if (url == null)
+            {
+                // Still not found, cache the not-found result
+                if (LOG.isDebugEnabled())
+                    LOG.debug("Caching not found resource {}", name);
+                _notFound.add(name);
+            }
+            else
+            {
+                // Cache the new result
+                _cache.putIfAbsent(name, url);
+            }
+        }
+
+        return url;
+    }
+
+    @Override
+    public Class<?> loadClass(String name) throws ClassNotFoundException
+    {
+        if (_notFound.contains(name))
+        {
+            if (LOG.isDebugEnabled())
+                LOG.debug("Not found cache hit resource {}", name);
+            throw new ClassNotFoundException(name + ": in notfound cache");
+        }
+        try
+        {
+            return super.loadClass(name);
+        }
+        catch (ClassNotFoundException nfe)
+        {
+            if (_notFound.add(name))
+                if (LOG.isDebugEnabled())
+                {
+                    LOG.debug("Caching not found {}", name, nfe);
+                }
+            throw nfe;
+        }
+    }
+
+    @ManagedOperation
+    public void clearCache()
+    {
+        _cache.clear();
+        _notFound.clear();
+    }
+
+    @Override
+    public String toString()
+    {
+        return "Caching[" + super.toString() + "]";
+    }
+}