Java :: Count the number of times a method is called

How to find how many times a method is used?

A general answer to this question would be something like this:

Static variable

public class MyClass {

    static int count = 0;

    public void myMethod() {
        count++;
    }
}

Using static int would seem a perfect solution. Static will share the instance variable count among all instances of MyClass. However, problem occurs in a multi threaded environment, as the count incrementation is not synchronised.

Multi-threaded

package com.deepumohan.tech.methodinvocationcount;
public class MyClass {

    static int count = 0;

    public void myMethod() {

        synchronized(this) {
            count++;
        }
    }
}

Now this works perfect in a multi-threaded environment.

Thread safe atomic class

Java provides a better option to use thread-safe increments through Atomic classes available in java.util.concurrent.atomic packag.

package com.deepumohan.tech.methodinvocationcount;
import java.util.concurrent.atomic.AtomicInteger;
public class MyClass {

    AtomicInteger atomicInteger = new AtomicInteger(0);

    public int getMethodInvocationCount() {
        return atomicInteger.incrementAndGet();
    }
}

Here is a good read about AtomicInteger vs static int: [Java - using AtomicInteger vs Static int] 1