Fixes memory leak in ResourceOracleImpl under GWT Designer.

While using GWT Designer the class path cache in ResourceOracleImpl never gets cleared of obsolete data.

http://gwt-code-reviews.appspot.com/1308801/show
Patch by: amitin
Review by: me


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9717 8db76d5a-ed1c-0410-87a9-c151d255dfc7

dev/core/src/com/google/gwt/dev/resource/impl/ResourceOracleImpl.java

diff --git a/dev/core/src/com/google/gwt/dev/resource/impl/ResourceOracleImpl.java b/dev/core/src/com/google/gwt/dev/resource/impl/ResourceOracleImpl.java
index d6dcb5b..9dfdbfa 100644
--- a/dev/core/src/com/google/gwt/dev/resource/impl/ResourceOracleImpl.java
+++ b/dev/core/src/com/google/gwt/dev/resource/impl/ResourceOracleImpl.java
@@ -24,6 +24,9 @@
 import com.google.gwt.dev.util.msg.Message0;
 import com.google.gwt.dev.util.msg.Message1String;
 
+import org.apache.commons.collections.map.AbstractReferenceMap;
+import org.apache.commons.collections.map.ReferenceMap;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
@@ -141,7 +144,9 @@
     }
   }
 
-  private static final Map<ClassLoader, List<ClassPathEntry>> classPathCache = new HashMap<ClassLoader, List<ClassPathEntry>>();
+  @SuppressWarnings("unchecked")
+  private static final Map<ClassLoader, List<ClassPathEntry>> classPathCache = new ReferenceMap(
+      AbstractReferenceMap.WEAK, AbstractReferenceMap.HARD);
 
   public static ClassPathEntry createEntryForUrl(TreeLogger logger, URL url)
       throws URISyntaxException, IOException {