Creating a documentation of a Java source file is not a big task, it can be done in just 3 steps which are explained below.

We use Javadoc tool to create documentation API for a java source file. Let's create a file with class name Documenttool and save this file with name Documenttool.java

Sample code:

Step 1: write a class and save it with .java as file extension (say Documenttool.java)

public class Documenttool {
	
public static int sum(int a , int b){
	return (a + b);
}

public static int minus(int a , int b){
		return (a - b);
}

}

Step 2: compile the file using the below command

javac Documenttool.java

Step 3: Now use the javadoc tool as below

javadoc Documenttool.java

Now, we can see in the current directory that a file is created with name Documenttool.html. On opening the Documenttool.html file in a text editor we will see that the Documenttool class is explained through documentation comment. Also, we can see the Documenttool.html in a browser.