--- old/src/java.base/share/classes/sun/misc/JarIndex.java	2015-05-18 18:36:20.279765435 -0700
+++ new/src/java.base/share/classes/sun/misc/JarIndex.java	2015-05-18 18:36:20.151765440 -0700
@@ -25,10 +25,26 @@
 
 package sun.misc;
 
-import java.io.*;
-import java.util.*;
-import java.util.jar.*;
-import java.util.zip.*;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.ByteBuffer;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Vector;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
 
 /**
  * This class is used to maintain mappings from packages, classes
@@ -74,6 +90,9 @@
     private static final boolean metaInfFilenames =
         "true".equals(System.getProperty("sun.misc.JarIndex.metaInfFilenames"));
 
+    private static final sun.misc.JavaUtilZipFileAccess zipAccess
+            = sun.misc.SharedSecrets.getJavaUtilZipFileAccess();
+
     /**
      * Constructs a new, empty jar index.
      */
@@ -134,7 +153,16 @@
         JarEntry e = jar.getJarEntry(INDEX_NAME);
         // if found, then load the index
         if (e != null) {
-            index = new JarIndex(jar.getInputStream(e));
+            long size = e.getSize();
+            if (size > 0 && size < 512 * 1024) {
+                byte[] bytes = new byte[(int) size];
+                ByteBuffer bb = ByteBuffer.wrap(bytes);
+                zipAccess.fillByteBuffer(jar, e, bb);
+                index = new JarIndex(new ByteArrayInputStream(bytes, 0, bb.position()));
+            } else {
+                // Unknown or too large ZipEntry size to use a array
+                index = new JarIndex(jar.getInputStream(e));
+            }
         }
         return index;
     }