Question

I’m having a really frustrating problem with SharedPreference.getBoolean in android. See the following snippet:

Map<String, ?> all = preferences.getAll();

Object x = all.get("EnableMedia");

boolean v = preferences.getBoolean("EnableMedia", (Boolean) null);

I can see in the debugger that ‘x’ is a Boolean and it is true.

Yet, if I execute the next line, preferences.getBoolean, it throws an exception. What gives?!

Answer 1

Look at this call:

preferences.getBoolean("EnableMedia", (Boolean) null);

Now look at the signature of getBoolean:

public abstract boolean getBoolean (String key, boolean defValue)

Note that it’s a boolean value, not a Boolean value. So what’s actually happening is your code is something like this:

Boolean tmp = null;
preferences.getBoolean("EnableMedia", tmp.booleanValue());

That will throw a NullPointerException, as you’re calling a method on a null reference.

You need to pass in a valid boolean value, e.g.

preferences.getBoolean("EnableMedia", true);