JSP学习笔记（8）_Servlet

以你之姓@ 2022-06-11 02:54 248阅读 0赞

**JSP学习笔记（8）\_Servlet（1）**

**1.结构体系**

> **HttpServlet <---(子类)--- GenericServlet(抽象类) ---(实现)---> (1)(2)(3)**
> 
> **(1)Servlet            (interfance) **
> 
> **(2)ServletConfig (interfance) **
> 
> **(3)Serializable     (interfance) 序列化接口**

**2.特点**

> **跨平台，可移植性**

**3.效率**

> **比JSP效率高**

**4.简单实现**

>     public class Test01 implements Servlet{
>     
>     	public void destroy() {
>     		// TODO Auto-generated method stub
>     		System.out.println("killed!!!");
>     	}
>     
>     	public ServletConfig getServletConfig() {
>     		// TODO Auto-generated method stub
>     		return null;
>     	}
>     
>     	public String getServletInfo() {
>     		// TODO Auto-generated method stub
>     		return null;
>     	}
>     
>     	public void init(ServletConfig config) throws ServletException {
>     		// TODO Auto-generated method stub
>     		System.out.println("出现了!!");
>     	}
>     
>     	public void service(ServletRequest req, ServletResponse res)
>     			throws ServletException, IOException {
>     		// TODO Auto-generated method stub
>     		//System.out.println("服务中...");
>     		HttpServletRequest request = (HttpServletRequest)req;
>     		HttpServletResponse response = (HttpServletResponse)res;
>     		String username = request.getParameter("username");
>     		PrintWriter out = response.getWriter();
>     		out.println("<html><head></head><body>");
>     		out.println("<h1>hello "+username+"!</h1>");
>     		out.println("</body></html>");
>     	}
>     
>     }
> 
> 方法以及作用：  
> 
> 
>     public void destroy()// 当服务器内存不足而导致servlet对象被调度或者关闭服务器时，serlet对象销毁前执行
> 
>     public ServletConfig getServletConfig()// 用于获取config对象
> 
>     public String getServletInfo()// 用于获取servlet的说明信息
> 
>     public void init(ServletConfig config) throws ServletException// 用于执行对象创建后{构造器执行后}的初始化操作，在整个Servlet对象的生命周期中运行且只运行一次
> 
>     public void service(ServletRequest req, ServletResponse res)
>     			throws ServletException, IOException// 用于对外提供服务,响应客户请求[URL],该方法以多线程的方式对外提供服务,服务完毕则常驻内存