Can a method parameter be final?

Hope you had already gone below usages of final keyword
1. final keyword with a class
2. final keyword with a method

As shown in below example it is possible to use final keyword for a parameter passed to a method.
Purpose of final keyword to a parameter is, the final object or primitive data type cannot be directly assigned to any other value, in the method body.

However, instance members of the class can be indirectly as shown in below example.

class MyTest{
	int i;
        public void setI(int x)
        i = x;

public class FinalParameter {
public static void main(String args[])
MyTest obj1 = new MyTest();
obj1.i = 10;
System.out.println("before invoking check():"+obj1.i);
System.out.println("after invoking check():"+obj1.i);
static void check(final MyTest obj)
//Below line produces Compile error, as obj is final
//obj = new MyTest();

//But below line is valid, as we are not changing the object
//rather we are just changing value of a instance variable
obj.i = 20;

//above value can also be changed by invoking the setI(int x) method
before invoking check():10
after invoking check():20

You may also like to read:

Can a constructor be final?
constants in Java
How to inherit from String class