What Java objects can be placed in the string literal pool?

In the String Pool in Java, objects of type String are stored, which are created as string literals in the code, for example, "hello". This allows the JVM to reuse identical string literals, saving memory.

It is important that only string literals and strings explicitly placed into the pool using the intern() method are included. For example:

String s1 = "hello"; // string literal, placed in the pool
String s2 = new String("hello"); // a new object is created in the heap
String s3 = s2.intern(); // s3 refers to the string from the pool

Thus, only objects of String created as literals or explicitly interned are in the pool, not any String objects.