Questions tagged as 'nullpointerexception'

So, I'm trying to make a program that adds 2 vectors via Thread , but it gives the following error:    Exception in thread "main" java.lang.NullPointerException       at Soma (Main.java:37)       at Main.main (Main.java:7) I wante...

Personally I need a help with an error in a method of my code. Basically I have a FrameLayout that loads two fragments. When you start the APP it loads the first fragment with 3 TextEdits and a button. When you click on the buton, it calls a...

I made an application that at a certain time low PDFs, however I can only download a PDF. I wanted to download several PDFs, see the project. The part that is giving the error is in for , where I try to call 3 times the part that reads the...