OPENJPA-2492. Committing a variation of the patch as provided by Romain Manni-Bucau. This patch clears up the ConcurrentHashMap issues relating to the KeySetView return type. This patch also adds a couple of asserts to an existing testcase to verify the results.

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@1589187 13f79535-47bb-0310-9956-ffa450edef68

openjpa-kernel/src/main/java/org/apache/openjpa/util/ProxyManagerImpl.java

@@ -1331,6 +1331,9 @@ public class ProxyManagerImpl
         Method match;
         Method after;
         for (int i = 0; i < meths.length; i++) {
+            // Java 8 methods with a return type of KeySetView do not need to be proxied
+            if (meths[i].getReturnType().getName().contains("KeySetView")) continue;
+
             params = toHelperParameters(meths[i].getParameterTypes(), 
                 proxyType);
 

openjpa-kernel/src/main/java/org/apache/openjpa/util/ProxyMaps.java

@@ -78,7 +78,8 @@ public class ProxyMaps
      */
     public static boolean beforeGet(ProxyMap map, Object key) {
         assertAllowedType(key, map.getKeyType());
-        return map.containsKey(key);
+        // Java 8 solution/workaround due to containsKey() calling get!=null, which could cause infinite loop
+        return map.keySet().contains(key);
     }
 
     /**

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/relations/TestConcurrentMap.java

@@ -44,5 +44,8 @@ public class TestConcurrentMap extends SingleEMTestCase {
         right.getLeftEntityMap().put(left.getStrData(), left);
         
         em.getTransaction().commit();
+        
+        assertEquals(1, right.getLeftEntityMap().size());
+        assertEquals(1, right.getLeftEntityMap().get(left.getStrData()).getId());
     }
 }