/** */
public interface Test {
    /** <p> </p>*/
    void p_end_p();
    /** <p> */
    void p_end();
    /** <p> <table summary="table"> <tr> <td> abc </table> */
    void p_table();
}

just reports:
$ javac -Xdoclint play/Test.java
play/Test.java:4: warning: empty <p> tag
    /** <p> </p>*/
            ^
1 warning