servlet的生命周期。

一个类extends HttpServlet。

public class TestServlet extends HttpServlet {



public TestServlet() {

super();
System.out.println("构造方法");
}



public void destroy() {
super.destroy(); 
System.out.println("destroy");
}


public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);

}



public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("service()");

}



public void init() throws ServletException {
System.out.println("init");
}


}

启动tomcat，在url输入地址访问该servlet。

输出为：

构造方法
init
service()

之后再访问，不再调用构造方法和init()方法，直接输出   service()

关闭tomcat，调用destroy()方法。