diff -r 97e3f3f77254 -r c44b88bb9b5e jdk/src/share/classes/java/lang/String.java
--- a/jdk/src/share/classes/java/lang/String.java	Thu May 17 10:06:19 2012 -0700
+++ b/jdk/src/share/classes/java/lang/String.java	Wed May 30 22:18:37 2012 -0700
@@ -25,7 +25,6 @@
 
 package java.lang;
 
-import java.io.ObjectStreamClass;
 import java.io.ObjectStreamField;
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
@@ -3021,4 +3020,100 @@
      */
     public native String intern();
 
+    /**
+     * Seed value used for each alternative hash calculated.
+     */
+    private static final int HASHING_SEED;
+
+    static {
+        long nanos = System.nanoTime();
+        long now = System.currentTimeMillis();
+        int SEED_MATERIAL[] = {
+                System.identityHashCode(String.class),
+                System.identityHashCode(System.class),
+                (int) (nanos >>> 32),
+                (int) nanos,
+                (int) (now >>> 32),
+                (int) now,
+                (int) (System.nanoTime() >>> 2)
+        };
+
+        // Use murmur3 to scramble the seeding material.
+        // Inline implementation to avoid loading classes
+        int h1 = 0;
+
+        // body
+        for(int k1 : SEED_MATERIAL) {
+            k1 *= 0xcc9e2d51;
+            k1 = (k1 << 15) | (k1 >>> 17);
+            k1 *= 0x1b873593;
+
+            h1 ^= k1;
+            h1 = (h1 << 13) | (h1 >>> 19);
+            h1 = h1 * 5 + 0xe6546b64;
+        }
+
+        // tail (always empty, as body is always 32-bit chunks)
+
+        // finalization
+
+        h1 ^= SEED_MATERIAL.length * 4;
+
+        // finalization mix force all bits of a hash block to avalanche
+        h1 ^= h1 >>> 16;
+        h1 *= 0x85ebca6b;
+        h1 ^= h1 >>> 13;
+        h1 *= 0xc2b2ae35;
+        h1 ^= h1 >>> 16;
+
+        HASHING_SEED = h1;
+    }
+
+    /**
+     * Cached value of the hashing algorithm result
+     */
+    private transient int hash32 = 0;
+
+    /**
+    * Return a 32-bit hash code value for this object.
+    * <p>
+    * The general contract of {@code hash32} is:
+    * <ul>
+    * <li>Whenever it is invoked on the same object more than once during
+    *     an execution of a Java application, the {@code hash32} method
+    *     must consistently return the same integer, provided no information
+    *     used in {@code equals} comparisons on the object is modified.
+    *     This integer need not remain consistent from one execution of an
+    *     application to another execution of the same application.
+    * <li>If two objects are equal according to the {@code equals(Object)}
+    *     method, then calling the {@code hash32} method on each of
+    *     the two objects must produce the same integer result.
+    * <li>It is <em>not</em> required that if two objects are unequal
+    *     according to the {@link java.lang.Object#equals(java.lang.Object)}
+    *     method, then calling the {@code hash32} method on each of the
+    *     two objects must produce distinct integer results.  However, the
+    *     programmer should be aware that producing distinct integer results
+    *     for unequal objects may improve the performance of hash tables.
+    * </ul>
+    * <p/>
+     * The hash value will never be zero.
+    *
+    * @return  a hash code value for this object.
+    * @see     java.lang.Object#equals(java.lang.Object)
+    */
+    public int hash32() {
+        int h = hash32;
+        if (0 == h) {
+           // harmless data race on hash32 here.
+           h = sun.misc.Hashing.murmur3_32(HASHING_SEED, value, 0, value.length);
+
+           // ensure result is not zero to avoid recalcing
+           h = (0 != h) ? h : 1;
+
+           hash32 = h;
+        }
+
+        return h;
+    }
+
 }