request.getRequestURI() 返回值類似:/xuejava/requestdemo.jsp
request.getRequestURL() 返回值類似:http://localhost:8080/xuejava/requestdemo.jsp
request.getRequestURI() 返回值類似:/xuejava/requestdemo.jsp
request.getRequestURL() 返回值類似:http://localhost:8080/xuejava/requestdemo.jsp