If you are fortunate enough to be using JDK 7, the newly available Objects class is the obvious (at least to me) choice for implementing the “common” Java object ...
It's not terribly clean, but you could use indexOf() and check if it returns -1. Better than breaking out a loop.
Java’s String class encapsulates an array of bytes. A byte can be converted to a char, in which case, String becomes an array of characters used to compose words, sentences, or any other data you want ...