Java Check String for Number This small program can be used to determine if a string contains numbers. This is useful for programs that want only number input from the user and Try Catch or for what ...

One of the nasty little traps a Java developer can run into occurs when Collection.contains(Object) is not used with appropriate understanding. I demonstrate this potential trap in this post.

Java gives you the ability to dynamically create strings. Even after you set the string value, you can add more characters to the string value throughout the code. This process lets you build a ...

At this point, the Scanner still returns a String, although the String contains only one character. To complete the use case, you must convert this one-character String into a single Java char with ...

I'm using a SharedPreferenceVault in my app and I received some NPE from some of my users (although very rarely) with the following stack trace: Caused by java.lang.NullPointerException: Attempt to ...

I have previously blogged on how Groovy and ActionScript provide demonstrations of switching on Strings functionality that has not been available in Java. JDK 7 changes this for Java by ...