Is it possible to programmatically force a string to be in the string pool in Java?

Yes, in Java, you can programmatically add a string to the string pool using the intern() method of the String class. This method returns a string from the string pool if it already exists there, or adds the current string to the pool and returns it.

Example:

String s = new String("example");
String interned = s.intern();

// Now interned points to a string from the string pool

This is useful for saving memory and speeding up string comparison using ==, since strings from the pool are unique objects.