Author: kturner
Date: Fri Jan 4 22:01:12 2013
New Revision: 1429150
URL: http://svn.apache.org/viewvc?rev=1429150&view=rev
Log:
ACCUMULO-930 moved indirection for reloading of classloaders to a higher level
Added:
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ReloadingClassLoader.java
Modified:
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoader.java
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoader.java
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ContextManager.java
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoaderTest.java
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoaderTest.java
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/ContextManagerTest.java
Modified:
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoader.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoader.java?rev=1429150&r1=1429149&r2=1429150&view=diff
==============================================================================
---
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoader.java
(original)
+++
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoader.java
Fri Jan 4 22:01:12 2013
@@ -16,12 +16,7 @@
*/
package org.apache.accumulo.start.classloader.vfs;
-import java.io.IOException;
-import java.io.InputStream;
-import java.net.URL;
-import java.security.SecureClassLoader;
import java.util.ArrayList;
-import java.util.Enumeration;
import org.apache.commons.vfs2.FileChangeEvent;
import org.apache.commons.vfs2.FileListener;
@@ -38,7 +33,7 @@ import org.apache.log4j.Logger;
* the delegate object if there is any change in the classpath.
*
*/
-public class AccumuloReloadingVFSClassLoader extends SecureClassLoader
implements FileListener {
+public class AccumuloReloadingVFSClassLoader implements FileListener,
ReloadingClassLoader {
private static final Logger log =
Logger.getLogger(AccumuloReloadingVFSClassLoader.class);
@@ -48,20 +43,16 @@ public class AccumuloReloadingVFSClassLo
private String uris;
private FileObject[] files;
private FileSystemManager vfs = null;
- private ClassLoader parent = null;
+ private ReloadingClassLoader parent = null;
private DefaultFileMonitor monitor = null;
- private volatile VFSClassLoader cl = null;
+ private VFSClassLoader cl = null;
- private synchronized VFSClassLoader getClassloader() {
- if (cl == null) {
+ @Override
+ public synchronized ClassLoader getClassLoader() {
+ if (cl == null || cl.getParent() != parent.getClassLoader()) {
try {
files = AccumuloVFSClassLoader.resolve(vfs, uris);
-
- if (null != parent)
- setClassloader(new VFSClassLoader(files, vfs, parent));
- else
- setClassloader(new VFSClassLoader(files, vfs));
-
+ setClassloader(new VFSClassLoader(files, vfs,
parent.getClassLoader()));
} catch (FileSystemException fse) {
throw new RuntimeException(fse);
}
@@ -75,9 +66,8 @@ public class AccumuloReloadingVFSClassLo
}
- public AccumuloReloadingVFSClassLoader(String uris, FileSystemManager vfs,
ClassLoader parent, long monitorDelay) throws FileSystemException {
- super(parent);
-
+ public AccumuloReloadingVFSClassLoader(String uris, FileSystemManager vfs,
ReloadingClassLoader parent, long monitorDelay) throws FileSystemException {
+
this.uris = uris;
this.vfs = vfs;
this.parent = parent;
@@ -85,10 +75,7 @@ public class AccumuloReloadingVFSClassLo
ArrayList<FileObject> pathsToMonitor = new ArrayList<FileObject>();
files = AccumuloVFSClassLoader.resolve(vfs, uris, pathsToMonitor);
- if (null != parent)
- cl = new VFSClassLoader(files, vfs, parent);
- else
- cl = new VFSClassLoader(files, vfs);
+ cl = new VFSClassLoader(files, vfs, parent.getClassLoader());
monitor = new DefaultFileMonitor(this);
monitor.setDelay(monitorDelay);
@@ -100,7 +87,7 @@ public class AccumuloReloadingVFSClassLo
monitor.start();
}
- public AccumuloReloadingVFSClassLoader(String uris, FileSystemManager vfs,
ClassLoader parent) throws FileSystemException {
+ public AccumuloReloadingVFSClassLoader(String uris, FileSystemManager vfs,
final ReloadingClassLoader parent) throws FileSystemException {
this(uris, vfs, parent, DEFAULT_TIMEOUT);
}
@@ -133,55 +120,7 @@ public class AccumuloReloadingVFSClassLo
setClassloader(null);
}
- @Override
- public Class<?> loadClass(String name) throws ClassNotFoundException {
- return this.getClassloader().loadClass(name);
- }
- @Override
- protected synchronized Class<?> loadClass(String name, boolean resolve)
throws ClassNotFoundException {
- return this.loadClass(name);
- }
-
- @Override
- protected Class<?> findClass(String name) throws ClassNotFoundException {
- return this.loadClass(name);
- }
-
- @Override
- public URL getResource(String name) {
- return this.getClassloader().getResource(name);
- }
-
- @Override
- public Enumeration<URL> getResources(String name) throws IOException {
- return this.getClassloader().getResources(name);
- }
-
- @Override
- public InputStream getResourceAsStream(String name) {
- return this.getClassloader().getResourceAsStream(name);
- }
-
- @Override
- public synchronized void setDefaultAssertionStatus(boolean enabled) {
- this.getClassloader().setDefaultAssertionStatus(enabled);
- }
-
- @Override
- public synchronized void setPackageAssertionStatus(String packageName,
boolean enabled) {
- this.getClassloader().setPackageAssertionStatus(packageName, enabled);
- }
-
- @Override
- public synchronized void setClassAssertionStatus(String className, boolean
enabled) {
- this.getClassloader().setClassAssertionStatus(className, enabled);
- }
-
- @Override
- public synchronized void clearAssertionStatus() {
- this.getClassloader().clearAssertionStatus();
- }
@Override
public String toString() {
@@ -199,5 +138,6 @@ public class AccumuloReloadingVFSClassLo
}
+
}
Modified:
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoader.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoader.java?rev=1429150&r1=1429149&r2=1429150&view=diff
==============================================================================
---
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoader.java
(original)
+++
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoader.java
Fri Jan 4 22:01:12 2013
@@ -76,7 +76,7 @@ public class AccumuloVFSClassLoader {
private static DefaultFileSystemManager vfs = null;
private static ClassLoader parent = null;
- private static volatile ClassLoader loader = null;
+ private static volatile ReloadingClassLoader loader = null;
private static final Object lock = new Object();
private static ContextManager contextManager;
@@ -154,7 +154,7 @@ public class AccumuloVFSClassLoader {
return classpath.toArray(new FileObject[classpath.size()]);
}
- private static ClassLoader createDynamicClassloader(ClassLoader parent)
throws FileSystemException, IOException {
+ private static ReloadingClassLoader createDynamicClassloader(final
ClassLoader parent) throws FileSystemException, IOException {
String dynamicCPath =
AccumuloClassLoader.getAccumuloString(DYNAMIC_CLASSPATH_PROPERTY_NAME,
DEFAULT_DYNAMIC_CLASSPATH_VALUE);
String envJars = System.getenv("ACCUMULO_XTRAJARS");
@@ -164,15 +164,22 @@ public class AccumuloVFSClassLoader {
else
dynamicCPath = envJars;
+ ReloadingClassLoader wrapper = new ReloadingClassLoader() {
+ @Override
+ public ClassLoader getClassLoader() {
+ return parent;
+ }
+ };
+
if (dynamicCPath == null || dynamicCPath.equals(""))
- return parent;
+ return wrapper;
// TODO monitor time for lib/ext was 1 sec... should this be configurable?
- return new AccumuloReloadingVFSClassLoader(dynamicCPath, vfs, parent,
1000);
+ return new AccumuloReloadingVFSClassLoader(dynamicCPath, vfs, wrapper,
1000);
}
public static ClassLoader getClassLoader() throws IOException {
- ClassLoader localLoader = loader;
+ ReloadingClassLoader localLoader = loader;
while (null == localLoader) {
synchronized (lock) {
if (null == loader) {
@@ -229,17 +236,17 @@ public class AccumuloVFSClassLoader {
if (vfsCP.length == 0) {
localLoader = createDynamicClassloader(parent);
loader = localLoader;
- return localLoader;
+ return localLoader.getClassLoader();
}
//Create the Accumulo Context ClassLoader using the DEFAULT_CONTEXT
- localLoader = new VFSClassLoader(vfsCP, vfs, parent);
- localLoader = createDynamicClassloader(localLoader);
+ localLoader = createDynamicClassloader(new VFSClassLoader(vfsCP,
vfs, parent));
loader = localLoader;
}
}
}
- return localLoader;
+
+ return localLoader.getClassLoader();
}
public static void printClassPath() {
@@ -271,8 +278,6 @@ public class AccumuloVFSClassLoader {
System.out.println("\t" + u.toExternalForm());
}
- } else if (classLoader instanceof AccumuloReloadingVFSClassLoader) {
- System.out.println("VFS classpaths items are:\n" +
classLoader.toString());
} else if (classLoader instanceof VFSClassLoader) {
System.out.println("VFS classpaths items are:");
VFSClassLoader vcl = (VFSClassLoader) classLoader;
@@ -291,10 +296,17 @@ public class AccumuloVFSClassLoader {
public static synchronized ContextManager getContextManager() throws
IOException {
- // TODO is there problem with using this lck?
-
if (contextManager == null) {
- contextManager = new ContextManager(vfs, getClassLoader());
+ contextManager = new ContextManager(vfs, new ReloadingClassLoader() {
+ @Override
+ public ClassLoader getClassLoader() {
+ try {
+ return AccumuloVFSClassLoader.getClassLoader();
+ } catch (IOException e) {
+ throw new RuntimeException(e);
+ }
+ }
+ });
}
return contextManager;
Modified:
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ContextManager.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ContextManager.java?rev=1429150&r1=1429149&r2=1429150&view=diff
==============================================================================
---
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ContextManager.java
(original)
+++
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ContextManager.java
Fri Jan 4 22:01:12 2013
@@ -58,9 +58,9 @@ public class ContextManager {
private volatile ContextConfig config;
private FileSystemManager vfs;
- private ClassLoader parent;
+ private ReloadingClassLoader parent;
- ContextManager(FileSystemManager vfs, ClassLoader parent) {
+ ContextManager(FileSystemManager vfs, ReloadingClassLoader parent) {
this.vfs = vfs;
this.parent = parent;
}
@@ -116,7 +116,7 @@ public class ContextManager {
return getClassLoader(contextName);
}
- return loader;
+ return loader.getClassLoader();
}
Added:
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ReloadingClassLoader.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ReloadingClassLoader.java?rev=1429150&view=auto
==============================================================================
---
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ReloadingClassLoader.java
(added)
+++
accumulo/trunk/start/src/main/java/org/apache/accumulo/start/classloader/vfs/ReloadingClassLoader.java
Fri Jan 4 22:01:12 2013
@@ -0,0 +1,24 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.accumulo.start.classloader.vfs;
+
+/**
+ *
+ */
+public interface ReloadingClassLoader {
+ ClassLoader getClassLoader();
+}
Modified:
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoaderTest.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoaderTest.java?rev=1429150&r1=1429149&r2=1429150&view=diff
==============================================================================
---
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoaderTest.java
(original)
+++
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloReloadingVFSClassLoaderTest.java
Fri Jan 4 22:01:12 2013
@@ -20,6 +20,8 @@ import java.net.URL;
import org.apache.accumulo.test.AccumuloDFSBase;
import org.apache.commons.vfs2.FileObject;
+import org.apache.commons.vfs2.FileSystemException;
+import org.apache.commons.vfs2.impl.VFSClassLoader;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.log4j.Level;
@@ -34,8 +36,7 @@ public class AccumuloReloadingVFSClassLo
private static final Path TEST_DIR = new Path(HDFS_URI + "/test-dir");
private FileSystem hdfs = null;
- private AccumuloReloadingVFSClassLoader cl = null;
-
+
@Before
public void setup() throws Exception {
Logger.getRootLogger().setLevel(Level.ERROR);
@@ -51,14 +52,36 @@ public class AccumuloReloadingVFSClassLo
}
+ FileObject[] createFileSystems(FileObject[] fos) throws FileSystemException {
+ FileObject[] rfos = new FileObject[fos.length];
+ for (int i = 0; i < fos.length; i++) {
+ if (vfs.canCreateFileSystem(fos[i]))
+ rfos[i] = vfs.createFileSystem(fos[i]);
+ else
+ rfos[i] = fos[i];
+ }
+
+ return rfos;
+ }
+
@Test
public void testConstructor() throws Exception {
FileObject testDir = vfs.resolveFile(TEST_DIR.toUri().toString());
FileObject[] dirContents = testDir.getChildren();
- cl = new AccumuloReloadingVFSClassLoader(TEST_DIR.toUri().toString(), vfs,
ClassLoader.getSystemClassLoader());
- FileObject[] files = cl.getFiles();
- Assert.assertArrayEquals(dirContents, files);
+ AccumuloReloadingVFSClassLoader arvcl = new
AccumuloReloadingVFSClassLoader(TEST_DIR.toUri().toString(), vfs, new
ReloadingClassLoader() {
+ @Override
+ public ClassLoader getClassLoader() {
+ return ClassLoader.getSystemClassLoader();
+ }
+ });
+
+ VFSClassLoader cl = (VFSClassLoader) arvcl.getClassLoader();
+
+ FileObject[] files = cl.getFileObjects();
+ Assert.assertArrayEquals(createFileSystems(dirContents), files);
+
+ arvcl.close();
}
@Test
@@ -66,16 +89,22 @@ public class AccumuloReloadingVFSClassLo
FileObject testDir = vfs.resolveFile(TEST_DIR.toUri().toString());
FileObject[] dirContents = testDir.getChildren();
- cl = new AccumuloReloadingVFSClassLoader(TEST_DIR.toUri().toString(), vfs,
ClassLoader.getSystemClassLoader(), 1000);
- FileObject[] files = cl.getFiles();
- Assert.assertArrayEquals(dirContents, files);
+ AccumuloReloadingVFSClassLoader arvcl = new
AccumuloReloadingVFSClassLoader(TEST_DIR.toUri().toString(), vfs, new
ReloadingClassLoader() {
+ @Override
+ public ClassLoader getClassLoader() {
+ return ClassLoader.getSystemClassLoader();
+ }
+ }, 1000);
+
+ FileObject[] files = ((VFSClassLoader)
arvcl.getClassLoader()).getFileObjects();
+ Assert.assertArrayEquals(createFileSystems(dirContents), files);
- Class<?> clazz1 = cl.loadClass("test.HelloWorld");
+ Class<?> clazz1 = arvcl.getClassLoader().loadClass("test.HelloWorld");
Object o1 = clazz1.newInstance();
Assert.assertEquals("Hello World!", o1.toString());
//Check that the class is the same before the update
- Class<?> clazz1_5 = cl.loadClass("test.HelloWorld");
+ Class<?> clazz1_5 = arvcl.getClassLoader().loadClass("test.HelloWorld");
Assert.assertEquals(clazz1, clazz1_5);
//Update the class
@@ -87,7 +116,7 @@ public class AccumuloReloadingVFSClassLo
//Wait for the monitor to notice
Thread.sleep(2000);
- Class<?> clazz2 = cl.loadClass("test.HelloWorld");
+ Class<?> clazz2 = arvcl.getClassLoader().loadClass("test.HelloWorld");
Object o2 = clazz2.newInstance();
Assert.assertEquals("Hello World!", o2.toString());
@@ -95,11 +124,11 @@ public class AccumuloReloadingVFSClassLo
Assert.assertFalse(clazz1.equals(clazz2));
Assert.assertFalse(o1.equals(o2));
+ arvcl.close();
}
@After
public void tearDown() throws Exception {
- cl.close();
this.hdfs.delete(TEST_DIR, true);
}
Modified:
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoaderTest.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoaderTest.java?rev=1429150&r1=1429149&r2=1429150&view=diff
==============================================================================
---
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoaderTest.java
(original)
+++
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/AccumuloVFSClassLoaderTest.java
Fri Jan 4 22:01:12 2013
@@ -55,7 +55,7 @@ public class AccumuloVFSClassLoaderTest
Whitebox.setInternalState(AccumuloClassLoader.class, "SITE_CONF", new
File(defaultDir.getPath() +
"/conf/accumulo-site.xml").toURI().toURL().toString());
Whitebox.setInternalState(AccumuloVFSClassLoader.class, "lock", new
Object());
ClassLoader acl = AccumuloVFSClassLoader.getClassLoader();
- Assert.assertTrue((acl instanceof AccumuloReloadingVFSClassLoader));
+ Assert.assertTrue((acl instanceof VFSClassLoader));
Assert.assertTrue((acl.getParent() instanceof URLClassLoader));
// URLClassLoader ucl = (URLClassLoader) acl;
@@ -88,7 +88,7 @@ public class AccumuloVFSClassLoaderTest
Whitebox.setInternalState(AccumuloClassLoader.class, "SITE_CONF", new
File(defaultDir.getPath() +
"/conf/accumulo-site.xml").toURI().toURL().toString());
Whitebox.setInternalState(AccumuloVFSClassLoader.class, "lock", new
Object());
ClassLoader acl = AccumuloVFSClassLoader.getClassLoader();
- Assert.assertTrue((acl instanceof AccumuloReloadingVFSClassLoader));
+ Assert.assertTrue((acl instanceof VFSClassLoader));
Assert.assertTrue((acl.getParent() instanceof VFSClassLoader));
VFSClassLoader arvcl = (VFSClassLoader) acl.getParent();
Assert.assertEquals(1, arvcl.getFileObjects().length);
Modified:
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/ContextManagerTest.java
URL:
http://svn.apache.org/viewvc/accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/ContextManagerTest.java?rev=1429150&r1=1429149&r2=1429150&view=diff
==============================================================================
---
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/ContextManagerTest.java
(original)
+++
accumulo/trunk/start/src/test/java/org/apache/accumulo/start/classloader/vfs/ContextManagerTest.java
Fri Jan 4 22:01:12 2013
@@ -22,6 +22,8 @@ import java.util.HashSet;
import org.apache.accumulo.start.classloader.vfs.ContextManager.ContextConfig;
import org.apache.accumulo.test.AccumuloDFSBase;
import org.apache.commons.vfs2.FileObject;
+import org.apache.commons.vfs2.FileSystemException;
+import org.apache.commons.vfs2.impl.VFSClassLoader;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.junit.After;
@@ -53,10 +55,28 @@ public class ContextManagerTest extends
}
+ FileObject[] createFileSystems(FileObject[] fos) throws FileSystemException {
+ FileObject[] rfos = new FileObject[fos.length];
+ for (int i = 0; i < fos.length; i++) {
+ if (vfs.canCreateFileSystem(fos[i]))
+ rfos[i] = vfs.createFileSystem(fos[i]);
+ else
+ rfos[i] = fos[i];
+ }
+
+ return rfos;
+ }
+
@Test
public void differentContexts() throws Exception {
- ContextManager cm = new ContextManager(vfs,
ClassLoader.getSystemClassLoader());
+ ContextManager cm = new ContextManager(vfs, new ReloadingClassLoader() {
+ @Override
+ public ClassLoader getClassLoader() {
+ return ClassLoader.getSystemClassLoader();
+ }
+ });
+
cm.setContextConfig(new ContextConfig() {
@Override
public String getContextURIs(String context) {
@@ -78,15 +98,14 @@ public class ContextManagerTest extends
FileObject testDir = vfs.resolveFile(TEST_DIR.toUri().toString());
FileObject[] dirContents = testDir.getChildren();
ClassLoader cl1 = cm.getClassLoader("CX1");
- FileObject[] files = ((AccumuloReloadingVFSClassLoader) cl1).getFiles();
- Assert.assertArrayEquals(dirContents, files);
-
+ FileObject[] files = ((VFSClassLoader) cl1).getFileObjects();
+ Assert.assertArrayEquals(createFileSystems(dirContents), files);
FileObject testDir2 = vfs.resolveFile(TEST_DIR2.toUri().toString());
FileObject[] dirContents2 = testDir2.getChildren();
ClassLoader cl2 = cm.getClassLoader("CX2");
- FileObject[] files2 = ((AccumuloReloadingVFSClassLoader) cl2).getFiles();
- Assert.assertArrayEquals(dirContents2, files2);
+ FileObject[] files2 = ((VFSClassLoader) cl2).getFileObjects();
+ Assert.assertArrayEquals(createFileSystems(dirContents2), files2);
Class<?> defaultContextClass = cl1.loadClass("test.HelloWorld");
Object o1 = defaultContextClass.newInstance();
