diff --git a/jetty-util/src/main/java/org/eclipse/jetty/util/resource/JarFileResource.java b/jetty-util/src/main/java/org/eclipse/jetty/util/resource/JarFileResource.java
index 3953bd02955..8dd5e59ecfc 100644
--- a/jetty-util/src/main/java/org/eclipse/jetty/util/resource/JarFileResource.java
+++ b/jetty-util/src/main/java/org/eclipse/jetty/util/resource/JarFileResource.java
@@ -15,6 +15,7 @@ package org.eclipse.jetty.util.resource;
 import java.io.File;
 import java.io.IOException;
 import java.net.JarURLConnection;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Enumeration;
@@ -318,6 +319,26 @@ class JarFileResource extends JarResource
         return newResource;
         
     }
+    
+    /**
+     * Check if this jar:file: resource is contained in the
+     * named resource. Eg jar:file:///a/b/c/foo.jar!/x.html isContainedIn file:///a/b/c/foo.jar
+     * @param resource
+     * @return
+     * @throws MalformedURLException
+     */
+    public boolean isContainedIn (Resource resource) 
+    throws MalformedURLException
+    {
+        String string = _urlString;
+        int index = string.indexOf("!/");
+        if (index > 0)
+            string = string.substring(0,index);
+        if (string.startsWith("jar:"))
+            string = string.substring(4);
+        URL url = new URL(string);
+        return url.sameFile(resource.getURL());     
+    }
 }
 
 
diff --git a/jetty-util/src/test/java/org/eclipse/jetty/util/resource/ResourceTest.java b/jetty-util/src/test/java/org/eclipse/jetty/util/resource/ResourceTest.java
index 81087ba4e18..2a4daa3e620 100644
--- a/jetty-util/src/test/java/org/eclipse/jetty/util/resource/ResourceTest.java
+++ b/jetty-util/src/test/java/org/eclipse/jetty/util/resource/ResourceTest.java
@@ -255,6 +255,22 @@ public class ResourceTest extends junit.framework.TestCase
         assertNotNull(jin);
         
     }
+    
+    public void testJarFileIsContainedIn ()
+    throws Exception
+    {
+        String s = "jar:"+__userURL+"TestData/test.zip!/subdir/";
+        Resource r = Resource.newResource(s);
+        Resource container = Resource.newResource(__userURL+"TestData/test.zip");
+        
+        assertTrue(r instanceof JarFileResource);
+        JarFileResource jarFileResource = (JarFileResource)r;
+        
+        assertTrue(jarFileResource.isContainedIn(container));
+        
+        container = Resource.newResource(__userURL+"TestData");
+        assertFalse(jarFileResource.isContainedIn(container));
+    }
 
     /**
      * Test a class path resource for existence.