Using the `javadoc` command (with examples)

The javadoc command is a powerful tool for generating Java API documentation in HTML format from source code. It allows developers to easily create comprehensive documentation for their Java projects.

In this article, we will explore three different use cases of the javadoc command, along with code examples and explanations for each case. We will cover generating documentation for Java source code, specifying a specific encoding, and excluding certain packages from the documentation.

Use Case 1: Generating documentation for Java source code and saving the result in a directory

Code:

javadoc -d path/to/directory/ path/to/java_source_code

Motivation: When developing a Java project, it is important to document the code and provide clear explanations of its functionality. Generating HTML documentation can help other developers better understand the project and its APIs.

Explanation:

• -d path/to/directory/ specifies the destination directory where the generated HTML documentation will be saved.
• path/to/java_source_code is the path to the Java source code for which the documentation is to be generated.

Example output: If we execute javadoc -d doc/ src/, the command will generate HTML documentation for all the Java files in the src/ directory and save the result in the doc/ directory.

Use Case 2: Generating documentation with a specific encoding

Code:

javadoc -docencoding UTF-8 path/to/java_source_code

Motivation: When generating documentation for Java source code that contains non-ASCII characters, it is important to ensure that the encoding used is compatible with those characters. Specifying a specific encoding, such as UTF-8, can help avoid any issues with character encoding.

Explanation:

• -docencoding UTF-8 specifies the encoding to be used for generating the documentation. In this case, we are using UTF-8 encoding.

Example output: If we execute javadoc -docencoding UTF-8 src/, the command will generate HTML documentation for all the Java files in the src/ directory using UTF-8 encoding.

Use Case 3: Generating documentation excluding some packages

Code:

javadoc -exclude package_list path/to/java_source_code

Motivation: In some cases, there may be packages in a Java project that do not need to be included in the generated documentation. Excluding these packages can help keep the documentation focused and concise.

Explanation:

• -exclude package_list specifies a list of packages to be excluded from the generated documentation.
• package_list is a comma-separated list of package names that are to be excluded.

Example output: If we execute javadoc -exclude com.example.util,com.example.internal src/, the command will generate HTML documentation for all the Java files in the src/ directory, excluding the com.example.util and com.example.internal packages.

By using the javadoc command, developers can easily generate comprehensive HTML documentation for their Java projects. These use cases illustrate different scenarios in which the command can be utilized to improve the documentation process. Whether it’s specifying a specific encoding, excluding certain packages, or simply generating documentation for source code, the javadoc command is a valuable tool for documenting Java projects.