请问test2() throw 的RuntimeException 为什么不需要test2() throws Exception 声明抛出异常？

public void test1() throws DrunkException{

    throw new DrunkException("喝车别开酒！");

}

public void test2(){

    try {

        test1();

    } catch (DrunkException e) {

    // TODO Auto-generated catch block

    RuntimeException newExc = 

        new RuntimeException(e);

        // newExc.initCause(e);

        throw newExc;

    }

}