Attempt to invoke virtual method 'boolean java.lang.Object.equals(java.lang.Object)' on a null object reference
49
What is a NullPointerException, and how do I fix it?
103930
How to ensure hashCode() is consistent with equals()?
33398
C# difference between == and Equals()
128865
The equals() method in Java works unexpectedly on Long data type
114604
How to compare two java objects
89755
Why is "throw null" not creating a compilation error in Java?
109282
Java comparison with == of two strings is false?
10581
Avoiding NullPointerException in Java
26674
Is there any way other than instanceof operator for object type comparison in java?
43489
Why does Boolean.ToString output "True" and not "true"
36686
Comparing strings with == which are declared final in Java
122494
Comparison Method violates its general contract in Java 7
104501
How do I enforce null checking?
131886
Why doesn't this method work? Java ternary operator
133055
Why do I need to override the equals and hashCode methods in Java?
38780
Checking for null before ToString()
152654
Comparing references in Java