Thread: How to solve “NullPointerException” in my Java Program ?

I just started java programming a 2 month ago , then i wrote a library system, but inside are full of “NullPointerException” , i have try many time but still cant solve it ,anyone here willing to help me to solve my problems and point out my program error ?

Post your code here, especially the line causing the NPE. First try to find which variable on the line is null. A debugger or debug statements (println) can help you here.

I have attach my program here, because is quite long , i thought is quite troublesome for you guys to read

This is download link of my program source codes java.doc.rar, please help me solve my problems as I really cannot solve it

java.doc.rar << my source codes

It's looking like folks don't want to see your whole program, particularly if they have to download it and particularly if it's long. If you still need our help and no decent answer is posted soon, you'll want to consider finding the line that's causing the NPE (the error message will tell you), investigate the variables on that line to see which are null, and then give this information with some of your code, preferably an SSCCE. Also, why are you reposting your link several times? That can get a bit annoying.

don't like to download...unknown things. Just post the codes you suspected

My friend, No one is gonna download and check your source code; specially unknown files.. Just post the code here, then we can help you to sort out your problem..

Originally Posted by unknowny

Wink How to solve “NullPointerException” in my Java Program ?

...initialize your variables.

post the code, or the error messages, and someone can tell you which variable. (or read the error message yourself and it will tell you)