package test.javassist.proxy;
import javassist.*;
import javassist.util.proxy.MethodFilter;
import javassist.util.proxy.MethodHandler;
import javassist.util.proxy.ProxyFactory;
import javassist.util.proxy.ProxyObject;
import junit.framework.TestCase;
/**
* test which checks that proxy classes are not retained after their classloader is released.
* this is a before and after test which validates JASSIST-104
*/
public class ProxyCacheGCTest extends TestCase
{
/**
* creates a large number of proxies in separate classloaders then lets go of the classloaders and
* forces a GC. If we run out of heap then we know there is a problem.
*/
public final static int REPETITION_COUNT = 10000;
private ClassPool basePool;
private CtClass baseHandler;
private CtClass baseFilter;
protected void setUp()
{
basePool = ClassPool.getDefault();
try {
baseHandler = basePool.get("javassist.util.proxy.MethodHandler");
baseFilter = basePool.get("javassist.util.proxy.MethodFilter");
} catch (NotFoundException e) {
e.printStackTrace();
fail("could not find class " + e);
}
}
public void testCacheGC()
{
ClassLoader oldCL = Thread.currentThread().getContextClassLoader();
try {
ProxyFactory.useCache = false;
for (int i = 0; i < REPETITION_COUNT; i++) {
ClassLoader newCL = new TestLoader();
try {
Thread.currentThread().setContextClassLoader(newCL);
createProxy(i);
} finally {
Thread.currentThread().setContextClassLoader(oldCL);
}
}
} finally {
ProxyFactory.useCache = true;
}
}
/**
* called when a specific classloader is in place on the thread to create a method handler, method filter
* and proxy in the current loader and then
*/
public void createProxy(int counter)
{
try {
ClassPool classPool = new ClassPool(basePool);
// create a target class in the current class loader
String targetName = "test.javassist.MyTarget_" + counter;
String targetConstructorName = "MyTarget_" + counter;
CtClass ctTargetClass = classPool.makeClass(targetName);
CtMethod targetMethod = CtNewMethod.make("public Object test() { return this; }", ctTargetClass);
ctTargetClass.addMethod(targetMethod);
CtConstructor targetConstructor = CtNewConstructor.make("public " + targetConstructorName + "() { }", ctTargetClass);
ctTargetClass.addConstructor(targetConstructor);
// create a handler in the current classloader
String handlerName = "test.javassist.MyHandler_" + counter;
CtClass ctHandlerClass = classPool.makeClass(handlerName);
ctHandlerClass.addInterface(baseHandler);
CtMethod handlerInvoke = CtNewMethod.make("public Object invoke(Object self, java.lang.reflect.Method thisMethod, java.lang.reflect.Method proceed, Object[] args) throws Throwable { return proceed.invoke(self, args); }", ctHandlerClass);
ctHandlerClass.addMethod(handlerInvoke);
// create a filter in the current classloader
String filterName = "test.javassist.MyFilter" + counter;
CtClass ctFilterClass = classPool.makeClass(filterName);
ctFilterClass.addInterface(baseFilter);
CtMethod filterIsHandled = CtNewMethod.make("public boolean isHandled(java.lang.reflect.Method m) { return true; }", ctFilterClass);
ctFilterClass.addMethod(filterIsHandled);
// now create a proxyfactory and use it to create a proxy
ProxyFactory factory = new ProxyFactory();
Class javaTargetClass = classPool.toClass(ctTargetClass);
Class javaHandlerClass = classPool.toClass(ctHandlerClass);
Class javaFilterClass = classPool.toClass(ctFilterClass);
MethodHandler handler= (MethodHandler)javaHandlerClass.newInstance();
MethodFilter filter = (MethodFilter)javaFilterClass.newInstance();
// ok, now create a factory and a proxy class and proxy from that factory
factory.setFilter(filter);
factory.setSuperclass(javaTargetClass);
// factory.setSuperclass(Object.class);
Class proxyClass = factory.createClass();
Object target = proxyClass.newInstance();
((ProxyObject)target).setHandler(handler);
} catch (Exception e) {
e.printStackTrace();
fail("cannot create proxy " + e);
}
}
/**
* a classloader which inherits from the system class loader and within which a proxy handler,
* filter and proxy will be located.
*/
public static class TestLoader extends ClassLoader
{
}
}