Fix possible memory leak in PropertyCache

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@558041 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/java/org/apache/fop/fo/properties/PropertyCache.java b/src/java/org/apache/fop/fo/properties/PropertyCache.java
index 0685ff514f84e60439aa8f2f4d0ffbabf118c19c..9acf12513c5c11bb2d128915e4e7cecf39877b62 100644 (file)
--- a/src/java/org/apache/fop/fo/properties/PropertyCache.java
+++ b/src/java/org/apache/fop/fo/properties/PropertyCache.java
@@ -19,6 +19,7 @@
 
 package org.apache.fop.fo.properties;
 
+import java.lang.ref.WeakReference;
 import java.util.Collections;
 import java.util.Map;
 import java.util.WeakHashMap;
@@ -35,6 +36,10 @@ public class PropertyCache {
     private Map propCache = Collections.synchronizedMap(new WeakHashMap());
     
     
+    public int size() {
+        return propCache.size();
+    }
+    
     /**
      *  Checks if the given property is present in the cache - if so, returns
      *  a reference to the cached value. Otherwise the given object is added
@@ -44,12 +49,14 @@ public class PropertyCache {
      */
     public Property fetch(Property prop) {
         
-        Property cacheEntry = (Property) propCache.get(prop);
-        if (cacheEntry != null) {
-            return cacheEntry;
-        } else {
-            propCache.put(prop, prop);
-            return prop;
+        WeakReference ref = (WeakReference) propCache.get(prop);
+        if (ref != null) {
+            Property cacheEntry = (Property)ref.get();
+            if (cacheEntry != null) {
+                return cacheEntry;                
+            }
         }
+        propCache.put(prop, new WeakReference(prop));
+        return prop;
     }
 }