It might be Netbeans, or it might be Java EE as a language, but that's the opposite of reliable. Stuff breaks when you breathe on it and is often fixed by something like deleting your Netbeans cache folder or just restarting Netbeans (after you've been hunting a Java bug for 2 hours). The most common phrase in class as people try to use this for a semester-long fourth-year programming project: "I didn't change anything, this worked yesterday when I went home!"