What is JavaDoc tool and how to use it?

The JavaDoc tool is a built-in documentation generator in Java that creates API documentation in HTML format. It helps developers easily maintain and share structured information about classes, methods, constructors, and fields. It helps developers:

• Create structured and professional documentation for classes, methods, and fields.
• Maintain and share readable code explanations across teams or projects.

JavaDoc Comments

Before using the JavaDoc tool, you must include JavaDoc comments in your source code. These comments provide descriptive information about your classes, methods, constructors, and fields.

Syntax:

/**

* This is a JavaDoc comment.

*/

Structure of a JavaDoc Comment

A typical JavaDoc comment consists of two parts:

• Description: General explanation of the code element.
• Block tags: Provide structured metadata such as @param, @return, @author, etc.

Generating JavaDoc Documentation

You can generate documentation from the command line or through an IDE.

Command Line Method: You don’t need to compile the .java file before generating JavaDoc.

Use the following command:

javadoc file_name.java

or for an entire package:

javadoc package_name

After execution, a set of HTML files will be created. Open the index.html file to view your documentation.

Generating JavaDoc in Eclipse 

• Go to Project -> Generate Javadoc.
• Choose the destination folder (default is in your workspace or C drive).
• Select the project or package to document.
• Choose specific classes and visibility level (public, protected, etc.).
• Click Next (optional: specify document title and other options).
• Click Finish to generate the documentation.

Example 1:

package exa;
import java.util.Scanner;

/**
*
* @author Yash
*/
public class Example{
    
/**
* This is a program for adding two numbers in java.
    * @param args
*/
    public static void main(String[] args){
        
        /**
        * This is the main method 
        * which is very important for 
        * execution for a java program.
        */

        int x, y;
        Scanner sc = new Scanner(System.in);
        
        /**
        * Declared two variables x and y. 
        * And taking input from the user 
        * by using Scanner class. 
        *
        */

        x = sc.nextInt();
        y = sc.nextInt();
        
        /**
        * Storing the result in variable sum 
        * which is of the integer type.
        */
        
        int sum = x + y;

        /**
        * Using standard output stream 
        * for giving the output.
        * @return null
        */
        
        System.out.println("Sum is: " + sum);
    }
}

Generate JavaDoc:

To generate documentation for the above package, run:

javadoc exa

This command will create a folder with HTML documentation files. Open index.html to view the API documentation in your browser.

Screenshot of javadoc:

Common JavaDoc Tags

Below is a list of commonly used tags with their descriptions and syntax: