X-Git-Url: http://wamblee.org/gitweb/?a=blobdiff_plain;f=support%2Fgeneral%2Fsrc%2Fmain%2Fjava%2Forg%2Fwamblee%2Fgeneral%2FThreadSpecificProxyFactory.java;h=e3b687df15777ac1fd07003c9d04ed272b925d66;hb=ee0d9727ac32c2680ed76571caff6cf44dd29514;hp=f7087296796d8a60ae14fc83139aed7603c5ef2e;hpb=86b68ca4594c43d09ca57f8a2f9522c604c76f1d;p=utils

diff --git a/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java b/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java
index f7087296..e3b687df 100644
--- a/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java
+++ b/support/general/src/main/java/org/wamblee/general/ThreadSpecificProxyFactory.java
@@ -16,15 +16,14 @@
 package org.wamblee.general;
 
 import java.lang.reflect.InvocationHandler;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 
 /**
  * Thread-specific proxy is used to create implementations of interfaces that
  * delegate to a thread-specific implementation of the service.
  * 
- * It is used for instance to pass a transaction scoped entity manager around.
+ * It can be used for instance to create a contextual reference to an entity manager 
+ * that delegates to a thread-specific instance. 
  * 
  * The {@link #set(Object)} method sets the current service instance for the current thread. 
  * The {@link #get()} method gets the current service instance for the current thread. 
@@ -32,7 +31,11 @@ import java.lang.reflect.Proxy;
  * instance. The result from this method can be passed at construction of an object that will be used
  * by multiple threads. 
  * 
- * This class is mostly used by other test tools. 
+ * 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.
@@ -40,21 +43,11 @@ import java.lang.reflect.Proxy;
  * 
  */
 public class ThreadSpecificProxyFactory<T> {
-    private class ThreadSpecificInvocationHandler implements InvocationHandler {
-
-        @Override
-        public Object invoke(Object aProxy, Method aMethod, Object[] aArgs)
-            throws Throwable {
-            try {
-                return aMethod.invoke(svc.get(), aArgs);
-            } catch (InvocationTargetException e) {
-                throw e.getCause();
-            }
-        }
-    }
-
-    private ThreadLocal<T> svc = new ThreadLocal<T>();
+   
+    
+    private ThreadLocal<T> svc;
     private Class clazz;
+    private T proxy; 
 
     /**
      * Constructs the factory.
@@ -67,7 +60,10 @@ public class ThreadSpecificProxyFactory<T> {
             throw new IllegalArgumentException("Class " + aClass.getName() +
                 " is not an interface");
         }
+        svc = new ThreadLocal<T>();
         clazz = aClass;
+        proxy = createProxy(); 
+        
     }
 
     /**
@@ -81,7 +77,9 @@ public class ThreadSpecificProxyFactory<T> {
     }
     
     /**
-     * Gets the current thread-specific service. 
+     * Gets the current thread-specific service.
+     * To get a contextual reference that can be used by any thread but delegates to a thread-specific
+     * instance, use {@link #getProxy()}.  
      * @return Service. 
      */
     public T get() { 
@@ -95,15 +93,19 @@ public class ThreadSpecificProxyFactory<T> {
      * @return Proxy.
      */
     public T getProxy() {
-        InvocationHandler handler = new ThreadSpecificInvocationHandler();
+        return proxy;
+    }
+
+    private T createProxy() {
+        InvocationHandler handler = new ThreadSpecificInvocationHandler(svc, clazz);
         Class proxyClass = Proxy.getProxyClass(clazz.getClassLoader(),
             new Class[] { clazz });
-        T proxy;
+        T proxyObj;
         try {
-            proxy = (T) proxyClass.getConstructor(
+            proxyObj = (T) proxyClass.getConstructor(
                 new Class[] { InvocationHandler.class }).newInstance(
                 new Object[] { handler });
-            return proxy;
+            return proxyObj;
         } catch (Exception e) {
             throw new RuntimeException("Could not create proxy for " +
                 clazz.getName(), e);