Does Java pass by reference or by value?

Java passes everything by value, and not by reference.
When passing an argument (or even multiple arguments) to a method, Java will create a copy and pass that to the method as arguments – and that is why it is called pass by value.

a variable of a class type stores an address of the object, and not the object itself.
Java manipulates objects 'by reference,' but it passes object references to methods 'by value.'

Also refer to http://www.javaranch.com/campfire/StoryPassBy.jsp
http://architects.dzone.com/articles/java-pass-value-and-not-pass-0

http://www.programmerinterview.com/index.php/java-questions/difference-between-a-primitive-type-and-a-class-type/

A variable of a class type – like a String – stores objects of its class differently from how variables of primitive types – like int or char – store their values. Every variable, whether it’s of a primitive type or of a class type, is implemented as a location in computer memory. For a variable of a primitive type, the value of the variable is stored in the memory location assigned to the variable. So, if an integer variable is declared as “int x = 3”, then when we look at the memory location of “x”, there will be a “3” stored there just as expected.

However, a variable of a class type only stores the memory address of where the object is located – not the values inside the object. So, if we have a class called “SomeClass”, when we create an object like this: “SomeClass anObject”, then when we look at “anObject” in memory, we will see that it does not store any of the variables that belong to that object in memory. Instead, the variable “anObject” just stores an address of another place in memory where all the details of “anObject” reside. This means that the object named by the variable is stored in some other location in memory and the variable contains only the memory address of where the object is stored. This memory address is called a reference to the object. If this is confusing, you will see an example of this further down.

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