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:

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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.

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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.

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

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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