All methods and attributes (including protected and private) must have a comment. The parameters, the exceptions thrown, and the method return should have a comment in the method comment. For example:

/**
 * This is an example that is used in the EasyBeans Code Convention.
 */
private int intValue;

/**
 * This is an example method to show a class comment.
 * @param a an example of parameter.
 * @param b other example of parameter.
 * @return the method result.
 * @throws Exception the exception thrown by the method.
 */
public int add(final int a, final int b) throws Exception {
    return a + b;
}