This to me sounds like a reasonably common problem that junior to intermediate developers tend to face at some point: they either don’t know or don’t trust the contracts they are participating in and defensively overcheck for nulls. Additionally, when writing their own code, they tend to rely on returning nulls to indicate something thus … Read more
String s1 = “”; means that the empty String is assigned to s1. In this case, s1.length() is the same as “”.length(), which will yield 0 as expected. String s2 = null; means that (null) or “no value at all” is assigned to s2. So this one, s2.length() is the same as null.length(), which will … Read more
I have your answers! Never close the db. It is that simple. Make sure you only have one, repeat, *one Helper instance per application. Share it with all threads. http://www.touchlab.co/blog/single-sqlite-connection/ Here’s some more info on the internals of sqlite and locking: http://www.touchlab.co/blog/android-sqlite-locking/
I had exactly the same error, although with other and more simpler code than yours. I found out that the problem occurred only if I didn’t close the app in the emulator after re-run it from eclipse. So if I close it before run it from eclipse, everything works fine. But since I am really … Read more
You are declaring an array of 2 hands. This is just setting up the array. You then need to instantiate the hand objects inside the array. Say hand[0] = new Hand(); hand[1] = new Hand();
NullPointerException means that mp is null. This means the MediaPlayer.create() failed. Does R.raw.alarm exist?
You’re expecting that the injected dependency is available before the bean is constructed. You’re expecting that it works like this: RequestBean requestBean; requestBean.sessionBean = sessionBean; // Injection. requestBean = new RequestBean(); // Constructor invoked. This is however not true and technically impossible. The dependencies are injected after construction. RequestBean requestBean; requestBean = new RequestBean(); // … Read more
Your app is crashing at: welcomePlayer.setText(“Welcome Back, ” + String.valueOf(mPlayer.getName(this)) + ” !”); because mPlayer=null. You forgot to initialize Player mPlayer in your PlayGame Activity. mPlayer = new Player(context,””);
Yes, catching any RuntimeException is almost always a code smell. The C2 Wiki seems to agree. An exception would probably be some specially defensive pieces of code which run pretty much random code from other modules. Examples for such defensive structures would be the EDT, ThreadPools/Executors and plugin system.
I would recommend you never throw NullPointerException by yourself. The main reason not to do this, as Thorbjørn Ravn Andersen says in a comment below, is that you don’t wan’t to mix ‘real, bad NPEs’ with NPEs thrown intentionally. So, until you’re confident that you’re able to recognize ‘valid’ NPE, I’d recommend to use IllegalArgumentException … Read more