How to Auto-Generate Javadoc Templates for Classes and Methods in IntelliJ IDEA

1. Class Comment Template

Open Settings → Editor → File and Code Templates, select the Class tab and add the following template (without the leading slash):

/**
 * @author jitwxs
 * @date ${YEAR}年${MONTH}月${DAY}日 ${TIME}
 */

2. Method Comment Template

In Settings → Editor → Live Templates create a new template group (e.g., userDefine) and add a new live template with abbreviation *. Set the description and template text as shown, ensure Expand with is Enter, and set applicable contexts to Java.

Template text (copy exactly):

*
 * @author jitwxs
 * @date $date$ $time$
 * @param $param$
 * @return $return$
 */

Define variables: date and time use IDEA built‑in functions. param uses a custom Groovy script:

groovyScript("def result = '';def params = \"${_1}\".replaceAll('[\\\\[|\\\\]|\\\\s]', '').split(',').toList(); for(i = 0; i < params.size(); i++) {if(params[i] != '') result+='* @param ' + params[i] + (i < params.size() - 1 ? '\\r\
 ' : '');}; return result == '' ? null : '\\r\
 ' + result", methodParameters())

And a custom script for return:

groovyScript("return \"${_1}\" == 'void' ? null : '\\r\
 * @return ' + \"${_1}\"", methodReturnType())

3. Verify the Result

When creating a new class, the class comment is inserted automatically.

Method comments are generated for various cases (no parameters, single parameter, multiple parameters, no return value, with return value).

4. Q & A

Why must the abbreviation be * and expand with Enter? Because IDEA triggers a template when the template name followed by the expand key is typed; * + Enter activates the Javadoc template.

Why is there an empty line with * in the template? It reserves a line for the method description, which can be removed if not needed.

Why are $time$$param$ placed together? The @param generation script was adjusted to avoid an empty line when there are no parameters, requiring the placeholders to be on the same line.

Why implement return manually instead of using methodReturnType() ? The built‑in function returns void for methods without a return value, which is not useful; the custom script only adds @return when a real return type exists.

Why is $return$ not on a separate line? When methodReturnType() returns null, handling a separate line causes backspace issues, so it is kept on the same line as other tags.