root/trunk/myweb/src/mypackage/PersonTest.java

package mypackage;

public class PersonTest {

  public static void main(String[] args) {
    Person thePerson=new Person();
    thePerson.run();

    Labor theLabor=new Labor();
    theLabor.run();

    thePerson=null;
    try {
      thePerson.run();
    } catch(Exception e) {
      System.out.println("例外発生："+e.getMessage());
    }
  }
}