Jetty 9.4.x 3755 annotation/jndi example cleanup (#3763)

* Issue #3755 Annotation example cleanup

+ Created JettyDistribution class as common utility to locate a jetty distribution for examples.
+ Fixed ServerWithAnnotations to correctly use the test-spec-webapp
+ Added AttributeContainerMap as a better way to treat attribute values as beans. This avoids them appearing twice in a dump and always associates them with their key.
+ Added NamingDump and use it in EnvConfiguration and jetty-plus.xml so that a server dump will contain dumps of the server local tree and each contexts java:comp/env tree
+ Improved the dump format of NamingContext and WebAppContext
+ Improved the toString format of several associated classes

Signed-off-by: Greg Wilkins <gregw@webtide.com>

examples/embedded/src/main/java/org/eclipse/jetty/embedded/JettyDistribution.java

@@ -0,0 +1,109 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.embedded;
+
+import java.io.File;
+import java.nio.file.Path;
+
+import org.eclipse.jetty.util.StringUtil;
+import org.eclipse.jetty.util.log.Log;
+import org.eclipse.jetty.util.log.Logger;
+
+/**
+ * A utility test class to locate a Jetty Distribution for testing purposes by searching:
+ * <ul>
+ *     <li>The <code>jetty.home</code> system property</li>
+ *     <li>The <code>JETTY_HOME</code> environment variable</li>
+ *     <li>The working directory hierarchy with subdirectory <code>jetty-distribution/target/home</code></li>
+ * </ul>
+ */
+public class JettyDistribution
+{
+    private final static Logger LOG = Log.getLogger(JettyDistribution.class);
+    public final static Path DISTRIBUTION;
+
+    static
+    {
+        Path distro = asJettyDistribution(System.getProperty("jetty.home"));
+        if (distro==null)
+            distro = asJettyDistribution(System.getenv().get("JETTY_HOME"));
+
+        if (distro==null)
+        {
+            try
+            {
+                Path working = new File(".").getAbsoluteFile().getCanonicalFile().toPath();
+                while(distro == null && working !=null )
+                {
+                    distro = asJettyDistribution(working.resolve("jetty-distribution/target/distribution").toString());
+                    working = working.getParent();
+                }
+            }
+            catch(Throwable th)
+            {
+                LOG.warn(th);
+            }
+        }
+        DISTRIBUTION = distro;
+    }
+
+    private static Path asJettyDistribution(String test)
+    {
+        try
+        {
+            if (StringUtil.isBlank(test))
+            {
+                LOG.info("asJettyDistribution {} is blank", test);
+                return null;
+            }
+
+            File dir = new File(test);
+            if (!dir.exists() || !dir.isDirectory())
+            {
+                LOG.info("asJettyDistribution {} is not a directory", test);
+                return null;
+            }
+
+            File demoBase = new File(dir,"demo-base");
+            if (!demoBase.exists() || !demoBase.isDirectory())
+            {
+                LOG.info("asJettyDistribution {} has no demo-base", test);
+                return null;
+            }
+
+            LOG.info("asJettyDistribution {}", dir);
+            return dir.getAbsoluteFile().getCanonicalFile().toPath();
+        }
+        catch(Exception e)
+        {
+            LOG.ignore(e);
+        }
+        return null;
+    }
+
+    public static Path resolve(String path)
+    {
+        return DISTRIBUTION.resolve(path);
+    }
+
+    public static void main(String... arg)
+    {
+        System.err.println("Jetty Distribution is " + DISTRIBUTION);
+    }
+}

examples/embedded/src/main/java/org/eclipse/jetty/embedded/LikeJettyXml.java

@@ -19,7 +19,6 @@
 package org.eclipse.jetty.embedded;
 
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.lang.management.ManagementFactory;
 
 import org.eclipse.jetty.deploy.DeploymentManager;
@@ -60,27 +59,14 @@ public class LikeJettyXml
     public static void main( String[] args ) throws Exception
     {
         // Path to as-built jetty-distribution directory
-        String jettyHomeBuild = "jetty-distribution/target/distribution";
+        String jettyHomeBuild = JettyDistribution.DISTRIBUTION.toString();
-        
+
         // Find jetty home and base directories
         String homePath = System.getProperty("jetty.home", jettyHomeBuild);
-        File start_jar = new File(homePath,"start.jar");
-        if (!start_jar.exists())
-        {
-            homePath = jettyHomeBuild = "jetty-distribution/target/distribution";
-            start_jar = new File(homePath,"start.jar");
-            if (!start_jar.exists())
-                throw new FileNotFoundException(start_jar.toString());
-        }
-
         File homeDir = new File(homePath);
 
         String basePath = System.getProperty("jetty.base", homeDir + "/demo-base");
         File baseDir = new File(basePath);
-        if(!baseDir.exists())
-        {
-            throw new FileNotFoundException(baseDir.getAbsolutePath());
-        }
         
         // Configure jetty.home and jetty.base system properties
         String jetty_home = homeDir.getAbsolutePath();
@@ -88,7 +74,6 @@ public class LikeJettyXml
         System.setProperty("jetty.home", jetty_home);
         System.setProperty("jetty.base", jetty_base);
 
-
         // === jetty.xml ===
         // Setup Threadpool
         QueuedThreadPool threadPool = new QueuedThreadPool();
@@ -219,7 +204,6 @@ public class LikeJettyXml
         lowResourcesMonitor.setPeriod(1000);
         lowResourcesMonitor.setLowResourcesIdleTimeout(200);
         lowResourcesMonitor.setMonitorThreads(true);
-        lowResourcesMonitor.setMaxConnections(0);
         lowResourcesMonitor.setMaxMemory(0);
         lowResourcesMonitor.setMaxLowResourcesTime(5000);
         server.addBean(lowResourcesMonitor);

examples/embedded/src/main/java/org/eclipse/jetty/embedded/OneWebApp.java

@@ -49,8 +49,7 @@ public class OneWebApp
         // PlusConfiguration) to choosing where the webapp will unpack itself.
         WebAppContext webapp = new WebAppContext();
         webapp.setContextPath("/");
-        File warFile = new File(
+        File warFile = JettyDistribution.resolve("demo-base/webapps/async-rest.war").toFile();
-                "../../tests/test-jmx/jmx-webapp/target/jmx-webapp");
         webapp.setWar(warFile.getAbsolutePath());
 
         // A WebAppContext is a ContextHandler as well so it needs to be set to

examples/embedded/src/main/java/org/eclipse/jetty/embedded/ServerWithAnnotations.java

@@ -21,6 +21,7 @@ package org.eclipse.jetty.embedded;
 import java.io.File;
 
 import org.eclipse.jetty.plus.jndi.EnvEntry;
+import org.eclipse.jetty.plus.jndi.NamingDump;
 import org.eclipse.jetty.plus.jndi.Resource;
 import org.eclipse.jetty.plus.jndi.Transaction;
 import org.eclipse.jetty.security.HashLoginService;
@@ -47,16 +48,14 @@ public class ServerWithAnnotations
         classlist.addBefore(
                 "org.eclipse.jetty.webapp.JettyWebXmlConfiguration",
                 "org.eclipse.jetty.annotations.AnnotationConfiguration");
-
         // Create a WebApp
         WebAppContext webapp = new WebAppContext();
         webapp.setContextPath("/");
-        File warFile = new File(
+        File warFile = JettyDistribution.resolve("demo-base/webapps/test-spec.war").toFile();
-                "jetty-distribution/target/distribution/demo-base/webapps/test.war");
         webapp.setWar(warFile.getAbsolutePath());
         webapp.setAttribute(
-                "org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",
+            "org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",
-                ".*/javax.servlet-[^/]*\\.jar$|.*/servlet-api-[^/]*\\.jar$");
+            ".*/javax.servlet-[^/]*\\.jar$|.*/servlet-api-[^/]*\\.jar$");
         server.setHandler(webapp);
 
         // Register new transaction manager in JNDI
@@ -64,10 +63,14 @@ public class ServerWithAnnotations
         new Transaction(new com.acme.MockUserTransaction());
 
         // Define an env entry with webapp scope.
-        new EnvEntry(webapp, "maxAmount", new Double(100), true);
+        // THIS ENTRY IS OVERRIDEN BY THE ENTRY IN jetty-env.xml
+        new EnvEntry(webapp, "maxAmount", 100d, true);
 
         // Register a mock DataSource scoped to the webapp
-        new Resource(webapp, "jdbc/mydatasource", new com.acme.MockDataSource());
+        new Resource(server, "jdbc/mydatasource", new com.acme.MockDataSource());
+
+        // Add JNDI context to server for dump
+        server.addBean(new NamingDump());
 
         // Configure a LoginService
         HashLoginService loginService = new HashLoginService();
@@ -75,6 +78,7 @@ public class ServerWithAnnotations
         loginService.setConfig("examples/embedded/src/test/resources/realm.properties");
         server.addBean(loginService);
 
+
         server.start();
         server.dumpStdErr();
         server.join();

jetty-jndi/src/main/java/org/eclipse/jetty/jndi/NamingContext.java

@@ -22,8 +22,10 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import javax.naming.Binding;
@@ -126,7 +128,7 @@ public class NamingContext implements Context, Dumpable
         this(env, name, parent, parser, null);
     }
 
-    private NamingContext(Hashtable<String,Object> env,
+    protected NamingContext(Hashtable<String,Object> env,
                          String name,
                          NamingContext parent,
                          NameParser parser,
@@ -143,14 +145,13 @@ public class NamingContext implements Context, Dumpable
     }
 
     /**
-     * @return A shallow copy of the Context with the same bindings, but a copy of the Env
+     * @return A shallow copy of the Context with the same bindings, but with the passed environment
      */
-    public NamingContext shallowCopy()
+    public Context shallowCopy(Hashtable<String, Object> env)
     {
-        return new NamingContext(_env, _name, _parent, _parser, _bindings);
+        return new NamingContext(env, _name, _parent, _parser, _bindings);
     }
 
-
     public boolean isDeepBindingSupported()
     {
         // look for deep binding support in _env
@@ -457,7 +458,7 @@ public class NamingContext implements Context, Dumpable
         {
             if(LOG.isDebugEnabled())
                 LOG.debug("Null or empty name, returning shallowCopy of this context");
-            return shallowCopy();
+            return shallowCopy(_env);
         }
 
         if (cname.size() == 1)
@@ -541,7 +542,7 @@ public class NamingContext implements Context, Dumpable
 
         if (cname == null || name.isEmpty())
         {
-            return shallowCopy();
+            return shallowCopy(_env);
         }
 
         if (cname.size() == 0)
@@ -1118,7 +1119,17 @@ public class NamingContext implements Context, Dumpable
     @Override
     public void dump(Appendable out,String indent) throws IOException
     {
-        Dumpable.dumpObjects(out,indent,this, _bindings);
+        Map<String, Object> bindings = new HashMap<>();
+        for (Map.Entry<String,Binding> binding : _bindings.entrySet())
+            bindings.put(binding.getKey(), binding.getValue().getObject());
+
+        Dumpable.dumpObject(out, this);
+        Dumpable.dumpMapEntries(out, indent, bindings, _env.isEmpty());
+        if (!_env.isEmpty())
+        {
+            out.append(indent).append("+> environment\n");
+            Dumpable.dumpMapEntries(out, indent + "   ", _env, true);
+        }
     }
 
     private Collection<Listener> findListeners()

jetty-jndi/src/main/java/org/eclipse/jetty/jndi/local/localContextRoot.java

@@ -270,7 +270,7 @@ public class localContextRoot implements Context
         if (cname == null || cname.isEmpty())
         {
             //If no name create copy of this context with same bindings, but with copy of the environment so it can be modified
-            return __root.shallowCopy();
+            return __root.shallowCopy(_env);
         }
 
         if (cname.size() == 0)
@@ -339,7 +339,7 @@ public class localContextRoot implements Context
 
         if ((cname == null) || cname.isEmpty())
         {
-            return __root.shallowCopy();
+            return __root.shallowCopy(_env);
         }
 
         if (cname.size() == 1)

jetty-plus/src/main/java/org/eclipse/jetty/plus/jndi/EnvEntry.java

@@ -56,4 +56,10 @@ public class EnvEntry extends NamingEntry
     {
         return this.overrideWebXml;
     }
+
+    @Override
+    protected String toStringMetaData()
+    {
+        return "OverrideWebXml=" + overrideWebXml;
+    }
 }

jetty-plus/src/main/java/org/eclipse/jetty/plus/jndi/Link.java

@@ -52,4 +52,10 @@ public class Link extends NamingEntry
     {
         return _link;
     }
+
+    @Override
+    protected String toStringMetaData()
+    {
+        return _link;
+    }
 }

jetty-plus/src/main/java/org/eclipse/jetty/plus/jndi/NamingDump.java

@@ -0,0 +1,71 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.plus.jndi;
+
+import javax.naming.InitialContext;
+
+import org.eclipse.jetty.util.StringUtil;
+import org.eclipse.jetty.util.component.Dumpable;
+
+/**
+ * A utility Dumpable to dump a JNDI naming context tree.
+ */
+public class NamingDump implements Dumpable
+{
+    private final ClassLoader _loader;
+    private final String _name;
+
+    public NamingDump()
+    {
+        this(null,"");
+    }
+
+    public NamingDump(ClassLoader loader, String name)
+    {
+        _loader = loader;
+        _name = name;
+    }
+
+    @Override
+    public void dump(Appendable out, String indent)
+    {
+        ClassLoader loader = Thread.currentThread().getContextClassLoader();
+        try
+        {
+            if (!StringUtil.isBlank(_name))
+                out.append(_name).append(" ");
+            if (_loader!=null)
+                Thread.currentThread().setContextClassLoader(_loader);
+            Object context = new InitialContext().lookup(_name);
+            if (context instanceof Dumpable)
+                ((Dumpable)context).dump(out, indent);
+            else
+                Dumpable.dumpObjects(out, indent, context);
+        }
+        catch(Throwable th)
+        {
+            throw new RuntimeException(th);
+        }
+        finally
+        {
+            if (_loader!=null)
+                Thread.currentThread().setContextClassLoader(loader);
+        }
+    }
+}

jetty-plus/src/main/java/org/eclipse/jetty/plus/jndi/NamingEntry.java

@@ -49,14 +49,7 @@ public abstract class NamingEntry
     protected String _namingEntryNameString; //the name of the NamingEntry relative to the context it is stored in
     protected String _objectNameString; //the name of the object relative to the context it is stored in
    
-   
+
-    @Override
-    public String toString()
-    {
-        return _jndiName;
-    }
- 
-    
     /**
      * Create a naming entry.
      * 
@@ -173,21 +166,21 @@ public abstract class NamingEntry
     /**
      * Save the NamingEntry for later use.
      * <p>
-     * Saving is done by binding the NamingEntry
+     * Saving is done by binding both the NamingEntry
      * itself, and the value it represents into
      * JNDI. In this way, we can link to the
      * value it represents later, but also
      * still retrieve the NamingEntry itself too.
      * <p>
-     * The object is bound at the jndiName passed in.
+     * The object is bound at scope/jndiName and
-     * This NamingEntry is bound at __/jndiName.
+     * the NamingEntry is bound at scope/__/jndiName.
      * <p>
      * eg
      * <pre>
      * jdbc/foo    : DataSource
      * __/jdbc/foo : NamingEntry
      * </pre>
-     * 
+     * @see NamingEntryUtil#getNameForScope(Object)
      * @param object the object to save 
      * @throws NamingException if unable to save
      */
@@ -212,5 +205,18 @@ public abstract class NamingEntry
         _objectNameString = objectName.toString();
         NamingUtil.bind(ic, _objectNameString, object);
     } 
-    
+
+    protected String toStringMetaData()
+    {
+        return null;
+    }
+
+    @Override
+    public String toString()
+    {
+        String metadata = toStringMetaData();
+        if (metadata == null)
+            return String.format("%s@%x{name=%s}", this.getClass().getName(), hashCode(), getJndiName());
+        return String.format("%s@%x{name=%s,%s}", this.getClass().getName(), hashCode(), getJndiName(), metadata);
+    }
 }

jetty-plus/src/main/java/org/eclipse/jetty/plus/jndi/NamingEntryUtil.java

@@ -118,7 +118,7 @@ public class NamingEntryUtil
      * @return all NameEntries of a certain type in the given naming environment scope (server-wide names or context-specific names)
      * @throws NamingException if unable to lookup the naming entries
      */
-    public static List<Object> lookupNamingEntries (Object scope, Class<?> clazz)
+    public static <T> List<? extends T> lookupNamingEntries (Object scope, Class<T> clazz)
     throws NamingException
     {
         try
@@ -127,7 +127,7 @@ public class NamingEntryUtil
             Context namingEntriesContext = (Context)scopeContext.lookup(NamingEntry.__contextName);
             ArrayList<Object> list = new ArrayList<Object>();
             lookupNamingEntries(list, namingEntriesContext, clazz);
-            return list;
+            return (List<T>)list;
         }
         catch (NameNotFoundException e)
         {

jetty-plus/src/main/java/org/eclipse/jetty/plus/webapp/EnvConfiguration.java

@@ -21,9 +21,7 @@ package org.eclipse.jetty.plus.webapp;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.List;
-
 import javax.naming.Binding;
 import javax.naming.Context;
 import javax.naming.InitialContext;
@@ -36,6 +34,7 @@ import org.eclipse.jetty.jndi.NamingContext;
 import org.eclipse.jetty.jndi.NamingUtil;
 import org.eclipse.jetty.jndi.local.localContextRoot;
 import org.eclipse.jetty.plus.jndi.EnvEntry;
+import org.eclipse.jetty.plus.jndi.NamingDump;
 import org.eclipse.jetty.plus.jndi.NamingEntryUtil;
 import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
@@ -54,6 +53,7 @@ public class EnvConfiguration extends AbstractConfiguration
 
     private static final String JETTY_ENV_BINDINGS = "org.eclipse.jetty.jndi.EnvConfiguration";
     private URL jettyEnvXmlUrl;
+    private NamingDump _dumper;
 
     public void setJettyEnvXml (URL url)
     {
@@ -128,6 +128,9 @@ public class EnvConfiguration extends AbstractConfiguration
 
         //add java:comp/env entries for any EnvEntries that have been defined so far
         bindEnvEntries(context);
+
+        _dumper = new NamingDump(context.getClassLoader(),"java:comp");
+        context.addBean(_dumper);
     }
 
 
@@ -138,6 +141,9 @@ public class EnvConfiguration extends AbstractConfiguration
     @Override
     public void deconfigure (WebAppContext context) throws Exception
     {
+        context.removeBean(_dumper);
+        _dumper = null;
+
         //get rid of any bindings for comp/env for webapp
         ClassLoader oldLoader = Thread.currentThread().getContextClassLoader();
         Thread.currentThread().setContextClassLoader(context.getClassLoader());
@@ -206,40 +212,23 @@ public class EnvConfiguration extends AbstractConfiguration
     public void bindEnvEntries (WebAppContext context)
     throws NamingException
     {
-        LOG.debug("Binding env entries from the jvm scope");
         InitialContext ic = new InitialContext();
         Context envCtx = (Context)ic.lookup("java:comp/env");
-        Object scope = null;
+
-        List<Object> list = NamingEntryUtil.lookupNamingEntries(scope, EnvEntry.class);
+        LOG.debug("Binding env entries from the jvm scope");
-        Iterator<Object> itor = list.iterator();
+        doBindings(envCtx, null);
-        while (itor.hasNext())
-        {
-            EnvEntry ee = (EnvEntry)itor.next();
-            ee.bindToENC(ee.getJndiName());
-            Name namingEntryName = NamingEntryUtil.makeNamingEntryName(null, ee);
-            NamingUtil.bind(envCtx, namingEntryName.toString(), ee);//also save the EnvEntry in the context so we can check it later
-        }
 
         LOG.debug("Binding env entries from the server scope");
-
+        doBindings(envCtx, context.getServer());
-        scope = context.getServer();
-        list = NamingEntryUtil.lookupNamingEntries(scope, EnvEntry.class);
-        itor = list.iterator();
-        while (itor.hasNext())
-        {
-            EnvEntry ee = (EnvEntry)itor.next();
-            ee.bindToENC(ee.getJndiName());
-            Name namingEntryName = NamingEntryUtil.makeNamingEntryName(null, ee);
-            NamingUtil.bind(envCtx, namingEntryName.toString(), ee);//also save the EnvEntry in the context so we can check it later
-        }
 
         LOG.debug("Binding env entries from the context scope");
-        scope = context;
+        doBindings(envCtx, context);
-        list = NamingEntryUtil.lookupNamingEntries(scope, EnvEntry.class);
+    }
-        itor = list.iterator();
+
-        while (itor.hasNext())
+    private void doBindings(Context envCtx, Object scope) throws NamingException
+    {
+        for (EnvEntry ee : NamingEntryUtil.lookupNamingEntries(scope, EnvEntry.class))
         {
-            EnvEntry ee = (EnvEntry)itor.next();
             ee.bindToENC(ee.getJndiName());
             Name namingEntryName = NamingEntryUtil.makeNamingEntryName(null, ee);
             NamingUtil.bind(envCtx, namingEntryName.toString(), ee);//also save the EnvEntry in the context so we can check it later

jetty-plus/src/main/plus-config/etc/jetty-plus.xml

@@ -22,5 +22,9 @@
     </Call>
   </Call>
 
+  <Call name="addBean">
+    <Arg><New class="org.eclipse.jetty.plus.jndi.NamingDump"/></Arg>
+  </Call>
+
 </Configure>
 

jetty-plus/src/test/java/org/eclipse/jetty/plus/jndi/TestNamingEntryUtil.java

@@ -18,6 +18,15 @@
 
 package org.eclipse.jetty.plus.jndi;
 
+import java.util.List;
+import javax.naming.Context;
+import javax.naming.InitialContext;
+import javax.naming.Name;
+import javax.naming.NameNotFoundException;
+import javax.naming.NamingException;
+
+import org.junit.jupiter.api.Test;
+
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.empty;
@@ -27,16 +36,6 @@ import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.fail;
 
-import java.util.List;
-
-import javax.naming.Context;
-import javax.naming.InitialContext;
-import javax.naming.Name;
-import javax.naming.NameNotFoundException;
-import javax.naming.NamingException;
-
-import org.junit.jupiter.api.Test;
-
 public class TestNamingEntryUtil
 {
     public class MyNamingEntry extends NamingEntry
@@ -122,7 +121,7 @@ public class TestNamingEntryUtil
     public void testLookupNamingEntries() throws Exception
     {
         ScopeA scope = new ScopeA();
-        List<?> list = NamingEntryUtil.lookupNamingEntries(scope, MyNamingEntry.class);
+        List<? extends MyNamingEntry> list = NamingEntryUtil.lookupNamingEntries(scope, MyNamingEntry.class);
         assertThat(list, is(empty()));
 
         MyNamingEntry mne1 = new MyNamingEntry(scope, "a/b", 1);

jetty-server/src/main/java/org/eclipse/jetty/server/LowResourceMonitor.java

@@ -18,6 +18,15 @@
 
 package org.eclipse.jetty.server;
 
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
 import org.eclipse.jetty.io.EndPoint;
 import org.eclipse.jetty.util.annotation.ManagedAttribute;
 import org.eclipse.jetty.util.annotation.ManagedObject;
@@ -29,15 +38,6 @@ import org.eclipse.jetty.util.thread.ScheduledExecutorScheduler;
 import org.eclipse.jetty.util.thread.Scheduler;
 import org.eclipse.jetty.util.thread.ThreadPool;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.concurrent.Executor;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
-
 
 /**
  *
@@ -135,7 +135,7 @@ public class LowResourceMonitor extends ContainerLifeCycle
 
     /**
      * @param maxConnections The maximum connections before low resources state is triggered
-     * @deprecated Replaced by ConnectionLimit
+     * @deprecated Replaced by {@link ConnectionLimit}
      */
     @Deprecated
     public void setMaxConnections(int maxConnections)

jetty-server/src/main/java/org/eclipse/jetty/server/Server.java

@@ -28,7 +28,6 @@ import java.util.Enumeration;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.Future;
-
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -47,7 +46,6 @@ import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.handler.HandlerWrapper;
 import org.eclipse.jetty.server.handler.StatisticsHandler;
 import org.eclipse.jetty.util.Attributes;
-import org.eclipse.jetty.util.AttributesMap;
 import org.eclipse.jetty.util.Jetty;
 import org.eclipse.jetty.util.MultiException;
 import org.eclipse.jetty.util.URIUtil;
@@ -55,6 +53,7 @@ import org.eclipse.jetty.util.Uptime;
 import org.eclipse.jetty.util.annotation.ManagedAttribute;
 import org.eclipse.jetty.util.annotation.ManagedObject;
 import org.eclipse.jetty.util.annotation.Name;
+import org.eclipse.jetty.util.component.AttributeContainerMap;
 import org.eclipse.jetty.util.component.LifeCycle;
 import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
@@ -75,7 +74,7 @@ public class Server extends HandlerWrapper implements Attributes
 {
     private static final Logger LOG = Log.getLogger(Server.class);
 
-    private final AttributesMap _attributes = new AttributesMap();
+    private final AttributeContainerMap _attributes = new AttributeContainerMap();
     private final ThreadPool _threadPool;
     private final List<Connector> _connectors = new CopyOnWriteArrayList<>();
     private SessionIdManager _sessionIdManager;
@@ -107,6 +106,7 @@ public class Server extends HandlerWrapper implements Attributes
         ServerConnector connector=new ServerConnector(this);
         connector.setPort(port);
         setConnectors(new Connector[]{connector});
+        addBean(_attributes);
     }
 
     /* ------------------------------------------------------------ */
@@ -584,9 +584,6 @@ public class Server extends HandlerWrapper implements Attributes
     @Override
     public void clearAttributes()
     {
-        Enumeration<String> names = _attributes.getAttributeNames();
-        while (names.hasMoreElements())
-            removeBean(_attributes.getAttribute(names.nextElement()));
         _attributes.clearAttributes();
     }
 
@@ -607,7 +604,7 @@ public class Server extends HandlerWrapper implements Attributes
     @Override
     public Enumeration<String> getAttributeNames()
     {
-        return AttributesMap.getAttributeNamesCopy(_attributes);
+        return _attributes.getAttributeNames();
     }
 
     /* ------------------------------------------------------------ */
@@ -617,9 +614,6 @@ public class Server extends HandlerWrapper implements Attributes
     @Override
     public void removeAttribute(String name)
     {
-        Object bean=_attributes.getAttribute(name);
-        if (bean!=null)
-            removeBean(bean);
         _attributes.removeAttribute(name);
     }
 
@@ -630,9 +624,6 @@ public class Server extends HandlerWrapper implements Attributes
     @Override
     public void setAttribute(String name, Object attribute)
     {
-        // TODO this is a crude way to get attribute values managed by JMX.
-        Object old=_attributes.getAttribute(name);
-        updateBean(old,attribute);        
         _attributes.setAttribute(name, attribute);
     }
 
@@ -693,7 +684,7 @@ public class Server extends HandlerWrapper implements Attributes
     @Override
     public void dump(Appendable out,String indent) throws IOException
     {
-        dumpObjects(out,indent,new ClassLoaderDump(this.getClass().getClassLoader()),_attributes);
+        dumpObjects(out,indent,new ClassLoaderDump(this.getClass().getClassLoader()));
     }
 
     /* ------------------------------------------------------------ */
@@ -714,6 +705,5 @@ public class Server extends HandlerWrapper implements Attributes
             _seconds = seconds;
             _dateField = dateField;
         }
-
     }
 }

jetty-util/src/main/java/org/eclipse/jetty/util/component/AttributeContainerMap.java

@@ -0,0 +1,82 @@
+//
+//  ========================================================================
+//  Copyright (c) 1995-2019 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.util.component;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.eclipse.jetty.util.Attributes;
+
+/**
+ * An Attributes implementation that holds it's values in an immutable {@link ContainerLifeCycle}
+ */
+public class AttributeContainerMap extends ContainerLifeCycle implements Attributes
+{
+    private final Map<String, Object> _map = new HashMap<>();
+
+    @Override
+    public synchronized void setAttribute(String name, Object attribute)
+    {
+        Object old = _map.put(name, attribute);
+        updateBean(old, attribute);
+    }
+
+    @Override
+    public synchronized void removeAttribute(String name)
+    {
+        Object removed = _map.remove(name);
+        if (removed != null)
+            removeBean(removed);
+    }
+
+    @Override
+    public synchronized Object getAttribute(String name)
+    {
+        return _map.get(name);
+    }
+
+    @Override
+    public synchronized Enumeration<String> getAttributeNames()
+    {
+        return Collections.enumeration(_map.keySet());
+    }
+
+    @Override
+    public synchronized void clearAttributes()
+    {
+        _map.clear();
+        this.removeBeans();
+    }
+
+    @Override
+    public void dump(Appendable out, String indent) throws IOException
+    {
+        Dumpable.dumpObject(out, this);
+        Dumpable.dumpMapEntries(out, indent, _map, true);
+    }
+
+    @Override
+    public String toString()
+    {
+        return String.format("%s@%x{size=%d}",this.getClass().getSimpleName(),hashCode(),_map.size());
+    }
+}

jetty-util/src/main/java/org/eclipse/jetty/util/component/Container.java

@@ -132,7 +132,7 @@ public interface Container
 
     /**
      * @param clazz the class of the beans
-     * @return the list of beans of the given class from the entire managed hierarchy
+     * @return the list of beans of the given class from the entire Container hierarchy
      * @param <T> the Bean type
      */
     public <T> Collection<T> getContainedBeans(Class<T> clazz);

jetty-util/src/main/java/org/eclipse/jetty/util/component/ContainerLifeCycle.java

@@ -550,13 +550,17 @@ public class ContainerLifeCycle extends AbstractLifeCycle implements Container,
     @Override
     public <T> Collection<T> getBeans(Class<T> clazz)
     {
-        ArrayList<T> beans = new ArrayList<>();
+        ArrayList<T> beans = null;
         for (Bean b : _beans)
         {
             if (clazz.isInstance(b._bean))
+            {
+                if (beans == null)
+                    beans = new ArrayList<>();
                 beans.add(clazz.cast(b._bean));
+            }
         }
-        return beans;
+        return beans == null ? Collections.emptyList() : beans;
     }
 
     @Override
@@ -879,7 +883,7 @@ public class ContainerLifeCycle extends AbstractLifeCycle implements Container,
 
     /**
      * @param clazz the class of the beans
-     * @return the list of beans of the given class from the entire managed hierarchy
+     * @return the list of beans of the given class from the entire Container hierarchy
      * @param <T> the Bean type
      */
     @Override
@@ -893,7 +897,7 @@ public class ContainerLifeCycle extends AbstractLifeCycle implements Container,
     /**
      * @param clazz the class of the beans
      * @param <T> the Bean type
-     * @param beans the collection to add beans of the given class from the entire managed hierarchy
+     * @param beans the collection to add beans of the given class from the entire Container hierarchy
      */
     protected <T> void getContainedBeans(Class<T> clazz, Collection<T> beans)
     {

jetty-util/src/main/java/org/eclipse/jetty/util/component/Dumpable.java

@@ -93,18 +93,19 @@ public interface Dumpable
             String s;
             if (o==null)
                 s = "null";
-            else if (o instanceof Collection)
-                s = String.format("%s@%x(size=%d)",o.getClass().getName(),o.hashCode(),((Collection)o).size());
-            else if (o.getClass().isArray())
-                s = String.format("%s@%x[size=%d]",o.getClass().getComponentType(),o.hashCode(), Array.getLength(o));
-            else if (o instanceof Map)
-                s = String.format("%s@%x{size=%d}",o.getClass().getName(),o.hashCode(),((Map<?,?>)o).size());
             else if (o instanceof Dumpable)
             {
                 s = ((Dumpable)o).dumpSelf();
                 s = StringUtil.replace(s, "\r\n", "|");
                 s = StringUtil.replace(s, '\n', '|');
             }
+            else if (o instanceof Collection)
+                s = String.format("%s@%x(size=%d)",o.getClass().getName(),o.hashCode(),((Collection)o).size());
+            else if (o.getClass().isArray())
+                s = String.format("%s@%x[size=%d]",o.getClass().getComponentType(),o.hashCode(), Array.getLength(o));
+            else if (o instanceof Map)
+                s = String.format("%s@%x{size=%d}",o.getClass().getName(),o.hashCode(),((Map<?,?>)o).size());
+            
             else
             {
                 s = String.valueOf(o);
@@ -139,7 +140,7 @@ public interface Dumpable
     {
         dumpObject(out,object);
 
-        int size = extraChildren==null?0:extraChildren.length;
+        int extras = extraChildren==null?0:extraChildren.length;
 
         if (object instanceof Stream)
             object = ((Stream)object).toArray();
@@ -148,87 +149,25 @@ public interface Dumpable
 
         if (object instanceof Container)
         {
-            Container container = (Container)object;
+            dumpContainer(out, indent, (Container)object, extras==0);
-            ContainerLifeCycle containerLifeCycle = container instanceof ContainerLifeCycle ? (ContainerLifeCycle)container : null;
-            for (Iterator<Object> i = container.getBeans().iterator(); i.hasNext();)
-            {
-                Object bean = i.next();
-                String nextIndent = indent + ((i.hasNext() || size>0) ? "|  " : "   ");
-                if (bean instanceof LifeCycle)
-                {
-                    if (container.isManaged(bean))
-                    {
-                        out.append(indent).append("+= ");
-                        if (bean instanceof Dumpable)
-                            ((Dumpable)bean).dump(out,nextIndent);
-                        else
-                            dumpObjects(out, nextIndent, bean);
-                    }
-                    else if (containerLifeCycle != null && containerLifeCycle.isAuto(bean))
-                    {
-                        out.append(indent).append("+? ");
-                        if (bean instanceof Dumpable)
-                            ((Dumpable)bean).dump(out,nextIndent);
-                        else
-                            dumpObjects(out, nextIndent, bean);
-                    }
-                    else
-                    {
-                        out.append(indent).append("+~ ");
-                        dumpObject(out, bean);
-                    }
-                }
-                else if (containerLifeCycle != null && containerLifeCycle.isUnmanaged(bean))
-                {
-                    out.append(indent).append("+~ ");
-                    dumpObject(out, bean);
-                }
-                else
-                {
-                    out.append(indent).append("+- ");
-                    if (bean instanceof Dumpable)
-                        ((Dumpable)bean).dump(out,nextIndent);
-                    else
-                        dumpObjects(out, nextIndent, bean);
-                }
-            }
         }
         if (object instanceof Iterable)
         {
-            for (Iterator i = ((Iterable<?>)object).iterator(); i.hasNext();)
+            dumpIterable(out, indent, (Iterable<?>)object, extras==0);
-            {
-                Object item = i.next();
-                String nextIndent = indent + ((i.hasNext() || size>0) ? "|  " : "   ");
-                out.append(indent).append("+: ");
-                if (item instanceof Dumpable)
-                    ((Dumpable)item).dump(out,nextIndent);
-                else
-                    dumpObjects(out,nextIndent, item);
-            }
         }
         else if (object instanceof Map)
         {
-            for (Iterator<? extends Map.Entry<?, ?>> i = ((Map<?,?>)object).entrySet().iterator(); i.hasNext();)
+            dumpMapEntries(out, indent, (Map<?,?>)object, extras==0);
-            {
-                Map.Entry entry = i.next();
-                String nextIndent = indent + ((i.hasNext() || size>0) ? "|  " : "   ");
-                out.append(indent).append("+@ ").append(String.valueOf(entry.getKey())).append('=');
-                Object item = entry.getValue();
-                if (item instanceof Dumpable)
-                    ((Dumpable)item).dump(out,nextIndent);
-                else
-                    dumpObjects(out,nextIndent, item);
-            }
         }
 
-        if (size==0)
+        if (extras==0)
             return;
 
         int i = 0;
         for (Object item : extraChildren)
         {
             i++;
-            String nextIndent = indent + (i<size ? "|  " : "   ");
+            String nextIndent = indent + (i<extras ? "|  " : "   ");
             out.append(indent).append("+> ");
             if (item instanceof Dumpable)
                 ((Dumpable)item).dump(out,nextIndent);
@@ -236,4 +175,91 @@ public interface Dumpable
                 dumpObjects(out, nextIndent, item);
         }
     }
+
+    static void dumpContainer(Appendable out, String indent, Container object, boolean last) throws IOException
+    {
+        Container container = object;
+        ContainerLifeCycle containerLifeCycle = container instanceof ContainerLifeCycle ? (ContainerLifeCycle)container : null;
+        for (Iterator<Object> i = container.getBeans().iterator(); i.hasNext();)
+        {
+            Object bean = i.next();
+            String nextIndent = indent + ((i.hasNext() || !last) ? "|  " : "   ");
+            if (bean instanceof LifeCycle)
+            {
+                if (container.isManaged(bean))
+                {
+                    out.append(indent).append("+= ");
+                    if (bean instanceof Dumpable)
+                        ((Dumpable)bean).dump(out,nextIndent);
+                    else
+                        dumpObjects(out, nextIndent, bean);
+                }
+                else if (containerLifeCycle != null && containerLifeCycle.isAuto(bean))
+                {
+                    out.append(indent).append("+? ");
+                    if (bean instanceof Dumpable)
+                        ((Dumpable)bean).dump(out,nextIndent);
+                    else
+                        dumpObjects(out, nextIndent, bean);
+                }
+                else
+                {
+                    out.append(indent).append("+~ ");
+                    dumpObject(out, bean);
+                }
+            }
+            else if (containerLifeCycle != null && containerLifeCycle.isUnmanaged(bean))
+            {
+                out.append(indent).append("+~ ");
+                dumpObject(out, bean);
+            }
+            else
+            {
+                out.append(indent).append("+- ");
+                if (bean instanceof Dumpable)
+                    ((Dumpable)bean).dump(out,nextIndent);
+                else
+                    dumpObjects(out, nextIndent, bean);
+            }
+        }
+    }
+
+    static void dumpIterable(Appendable out, String indent, Iterable<?> iterable, boolean last) throws IOException
+    {
+        for (Iterator i = iterable.iterator(); i.hasNext();)
+        {
+            Object item = i.next();
+            String nextIndent = indent + ((i.hasNext() || !last) ? "|  " : "   ");
+            out.append(indent).append("+: ");
+            if (item instanceof Dumpable)
+                ((Dumpable)item).dump(out,nextIndent);
+            else
+                dumpObjects(out,nextIndent, item);
+        }
+
+    }
+
+    static void dumpMapEntries(Appendable out, String indent, Map<?,?> map, boolean last) throws IOException
+    {
+        for (Iterator<? extends Map.Entry<?, ?>> i = map.entrySet().iterator(); i.hasNext();)
+        {
+            Map.Entry entry = i.next();
+            String nextIndent = indent + ((i.hasNext() || !last) ? "|  " : "   ");
+            out.append(indent).append("+@ ").append(String.valueOf(entry.getKey())).append(" = ");
+            Object item = entry.getValue();
+            if (item instanceof Dumpable)
+                ((Dumpable)item).dump(out,nextIndent);
+            else
+                dumpObjects(out,nextIndent, item);
+        }
+    }
+
+    static Dumpable named(String name, Object object)
+    {
+        return (out, indent) ->
+        {
+            out.append(name).append(": ");
+            Dumpable.dumpObjects(out, indent, object);
+        };
+    }
 }

jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppClassLoader.java

@@ -724,7 +724,7 @@ public class WebAppClassLoader extends URLClassLoader implements ClassVisibility
     @Override
     public String toString()
     {
-        return "WebAppClassLoader=" + _name+"@"+Long.toHexString(hashCode());
+        return String.format("%s{%s}@%x", this.getClass().getSimpleName(), _name, hashCode());
     }
 
     @Override

jetty-webapp/src/main/java/org/eclipse/jetty/webapp/WebAppContext.java

@@ -34,7 +34,6 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-
 import javax.servlet.ServletContext;
 import javax.servlet.ServletRegistration.Dynamic;
 import javax.servlet.ServletSecurityElement;
@@ -1040,15 +1039,10 @@ public class WebAppContext extends ServletContextHandler implements WebAppClassL
     public String toString()
     {
         if (_war!=null)
-        {
+            return super.toString()+"{"+_war+"}";
-            String war=_war;
-            if (war.indexOf("/webapps/")>=0)
-                war=war.substring(war.indexOf("/webapps/")+8);
-            return super.toString()+"{"+war+"}";
-        }
         return super.toString();
     }
-    
+
     /* ------------------------------------------------------------ */
     @Override
     public void dump(Appendable out, String indent) throws IOException
@@ -1066,15 +1060,39 @@ public class WebAppContext extends ServletContextHandler implements WebAppClassL
             server_classes=new ArrayList<>(_serverClasses);
             Collections.sort(server_classes);
         }
-        
+
+        String name = getDisplayName();
+        if (name == null)
+        {
+            if (_war != null)
+            {
+                if (_war.indexOf("/webapps/") >= 0)
+                    name = _war.substring(_war.indexOf("/webapps/") + 8);
+                else
+                    name = _war;
+            }
+            else if (getResourceBase() != null)
+            {
+                name = getResourceBase();
+                if (name.indexOf("/webapps/") >= 0)
+                    name =  name.substring(name.indexOf("/webapps/") + 8);
+            }
+            else
+            {
+                name = this.getClass().getSimpleName();
+            }
+        }
+
+        name = String.format("%s@%x", name, hashCode());
+
         dumpObjects(out,indent,
             new ClassLoaderDump(getClassLoader()),
-            new DumpableCollection("Systemclasses "+this,system_classes),
+            new DumpableCollection("Systemclasses " + name, system_classes),
-            new DumpableCollection("Serverclasses "+this,server_classes),
+            new DumpableCollection("Serverclasses " + name, server_classes),
-            new DumpableCollection("Configurations "+this,_configurations),
+            new DumpableCollection("Configurations " + name, _configurations),
-            new DumpableCollection("Handler attributes "+this,((AttributesMap)getAttributes()).getAttributeEntrySet()),
+            new DumpableCollection("Handler attributes " + name, ((AttributesMap)getAttributes()).getAttributeEntrySet()),
-            new DumpableCollection("Context attributes "+this,((Context)getServletContext()).getAttributeEntrySet()),
+            new DumpableCollection("Context attributes " + name, ((Context)getServletContext()).getAttributeEntrySet()),
-            new DumpableCollection("Initparams "+this,getInitParams().entrySet())
+            new DumpableCollection("Initparams " + name, getInitParams().entrySet())
             );
     }