Java: Why is constant pool maintained only for String values ?

Question

My question is about java interning and constant pools.

Java maintains a a constants pool for java.lang.String, to use JVM memory cleverly, and to do so jav

Answer 1

Well, because String objects are immutable, it's safe for multiple references to "share" the same String object.

public class ImmutableStrings
{
public static void main(String[] args)
{
    String one = "str1";
    String two = "str1";

    System.out.println(one.equals(two));
    System.out.println(one == two);
}
}

// Output

true
true

In such a case, there is really no need to make two instances of an identical String object. If a String object could be changed, as a StringBuffer can be changed, we would be forced to create two separate objects. But, as we know that String objects cannot change, we can safely share a String object among the two String references, one and two. This is done through the String literal pool.

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