Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object
49
What is a NullPointerException, and how do I fix it?
67597
Can constructor return a null object?
154049
why does if("string") evaluate "string" as true but if ("string"==true) does not?
43489
Why does Boolean.ToString output "True" and not "true"
36686
Comparing strings with == which are declared final in Java
108336
Nullable Object must have a value #2
17784
Java if ternary operator and Collections.emptyList()
47233
Cannot perform instanceof check against parameterized type ArrayList
141442
Why does my string comparison fail?
78156
String.equals() with multiple conditions (and one action on result)
89052
When overriding equals in Java, why does it not work to use a parameter other than Object?
31537
Checking for null before event dispatching... thread safe?
77550
How do I set a property on a mocked object using Mockito?
115423
How to check null objects in jQuery
123797
Not equal  != operator on NULL
147409
String.equals versus ==
15097
Is there any difference between IS NULL and =NULL