Immutable Map 

Google Guava is a java library with lot of utilities and reusable components. This requires the library guava-10.0.jar to be in classpath. The following example shows using ImmutableMap class. It returns an immutable map implementation which doesn't allow null keys and values.

File Name  :   com/bethecoder/tutorials/guava/collection_tests/ImmutableMapTest.java  Author  :   Sudhakar KV Email  :   [email protected]

package com.bethecoder.tutorials.guava.collection_tests; import java.util.Map; import com.google.common.collect.ImmutableMap; public class ImmutableMapTest {   /**    * @param args    */   public static void main(String[] args) {     Map<String, Integer> immutableMap = ImmutableMap.of("ONE", 1, "TWO", 2, "THREE", 3);     System.out.println(immutableMap);   } }

{ONE=1, TWO=2, THREE=3}