--- /dev/null
+/*
+ * Copyright 2005-2010 the original author or authors.
+ *
+ * Licensed 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.wamblee.general;
+
+import java.io.Serializable;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Invocation handler for thread-specific proxies.
+ *
+ * @author Erik Brakkee
+ *
+ * @param <T>
+ */
+class ThreadSpecificInvocationHandler<T> implements InvocationHandler, Serializable {
+
+ /**
+ * We store a map of unique ids of invocation handlers to thread local storage of the
+ * service. In this way, serialiability of the generated proxy is obtained (required by
+ * framweorks such as wicket). Also, different factories will still be separate and never
+ * use the same threadlocal storage.
+ */
+ private static Map<Integer,ThreadLocal> STORAGE = initializeThreadLocal();
+
+ private static AtomicInteger COUNTER = new AtomicInteger();
+
+ private static Map<Integer, ThreadLocal> initializeThreadLocal() {
+ Map<Integer,ThreadLocal> map = new ConcurrentHashMap<Integer,ThreadLocal>();
+ return map;
+ }
+
+
+ private int id;
+ private Class clazz;
+
+ /**
+ * Constructs the handler.
+ * @param aSvc Thread local for the service.
+ * @param aClass Service interface class.
+ */
+ public ThreadSpecificInvocationHandler(ThreadLocal aSvc, Class aClass) {
+ id = COUNTER.incrementAndGet();
+ clazz = aClass;
+ STORAGE.put(id, aSvc);
+ }
+
+ @Override
+ public Object invoke(Object aProxy, Method aMethod, Object[] aArgs)
+ throws Throwable {
+
+ ThreadLocal<T> local = STORAGE.get(id);
+ T actualSvc = local.get();
+ if ( aMethod.getName().equals("toString") && actualSvc == null) {
+ return "Thread-specific proxy for '" + clazz.getName() + "' id = " + id;
+ }
+ try {
+ return aMethod.invoke(actualSvc, aArgs);
+ } catch (InvocationTargetException e) {
+ throw e.getCause();
+ }
+ }
+}
\ No newline at end of file
*/
package org.wamblee.general;
-import java.io.Serializable;
import java.lang.reflect.InvocationHandler;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.UUID;
/**
* Thread-specific proxy is used to create implementations of interfaces that
*
* This class is mostly used by infrastructure code (utilities) and test tools.
*
+ * Care has been taken so that the invocation handler is serializable.
+ * However, it is only serializable within one virtual machine. It cannot be used in a distributed context
+ * where it can be sent to another JVM.
+ *
* @param T
* Interface to proxy.
* @author Erik Brakkee
*
*/
public class ThreadSpecificProxyFactory<T> {
+
- /**
- * We store a map of unique ids of invocation handlers to thread local storage of the
- * service. In this way, serialiability of the generated proxy is obtained (required by
- * framweorks such as wicket). Also, different factories will still be separate and never
- * use the same threadlocal storage.
- */
- private static Map<String,ThreadLocal> STORAGE =
- initializeThreadLocal();
-
- private static class ThreadSpecificInvocationHandler<T> implements InvocationHandler, Serializable {
-
- private String id;
- private Class clazz;
-
- public ThreadSpecificInvocationHandler(String aId, Class aClass) {
- id = aId;
- clazz = aClass;
- }
-
- @Override
- public Object invoke(Object aProxy, Method aMethod, Object[] aArgs)
- throws Throwable {
- ThreadLocal<T> local = STORAGE.get(id);
- T actualSvc = local.get();
- if ( aMethod.getName().equals("toString") && actualSvc == null) {
- return "Thread-specific proxy for '" + clazz.getName() + "'";
- }
- try {
- return aMethod.invoke(actualSvc, aArgs);
- } catch (InvocationTargetException e) {
- throw e.getCause();
- }
- }
- }
-
private ThreadLocal<T> svc;
private Class clazz;
private T proxy;
svc = new ThreadLocal<T>();
clazz = aClass;
proxy = createProxy();
- }
-
- private static Map<String, ThreadLocal> initializeThreadLocal() {
- Map<String,ThreadLocal> map = new HashMap<String,ThreadLocal>();
- return map;
+
}
/**
}
private T createProxy() {
- String id = UUID.randomUUID().toString();
- STORAGE.put(id, svc);
- InvocationHandler handler = new ThreadSpecificInvocationHandler(id, clazz);
+ InvocationHandler handler = new ThreadSpecificInvocationHandler(svc, clazz);
Class proxyClass = Proxy.getProxyClass(clazz.getClassLoader(),
new Class[] { clazz });
T proxyObj;
git://wamblee.org / utils / commitdiff