.NET Framework 4 introduces a new method on its String class called IsNullOrWhiteSpace that checks whether a provided String is null, empty, or consists only of “white space.” This handy method is in ...

It doesn’t take much Java development experience to learn firsthand what the NullPointerException is about. In fact, one person has highlighted dealing with this as the number one mistake Java ...

You should be using the tokenize to actually parse the sentences. If you tokenize on spaces then you can put spaces in where needed (between words) and not have to worry about 'removing' them.