JavaEE编程基础:Servlet核心API用法详解( 二 )


2、代码案例

  • 配置文件
<servlet> <servlet-name>servletThreeImpl</servlet-name> <servlet-class>com.node02.servlet.impl.ServletThreeImpl</servlet-class></servlet><servlet-mapping> <servlet-name>servletThreeImpl</servlet-name> <url-pattern>/servletThreeImpl</url-pattern></servlet-mapping>
  • API用法
public class ServletThreeImpl extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // http://localhost:6003/servletThreeImpl?myName=cicada String method = request.getMethod(); System.out.println("method="+method); // GET String requestURL = request.getRequestURL().toString(); // http://localhost:6003/servletThreeImpl System.out.println("requestURL="+requestURL); String requestURI = request.getRequestURI(); System.out.println("requestURI="+requestURI); // /servletThreeImpl String queryString = request.getQueryString() ; System.out.println("queryString="+queryString); // myName=cicada String myName = request.getParameter("myName"); System.out.println("myName="+myName); // cicada }}五、ServletResponse接口1、接口简介
HttpServletResponse继承自ServletResponse , 封装了Http响应信息 。客户端每个请求 , 服务器都会创建一个response对象 , 并传入给Servlet.service()方法 。核心作用:1.设置响应头信息;2.发送状态码;3.设置响应正文;4.重定向;
2、代码案例
  • 配置文件
<servlet> <servlet-name>servletFourImpl</servlet-name> <servlet-class>com.node02.servlet.impl.ServletFourImpl</servlet-class></servlet><servlet-mapping> <servlet-name>servletFourImpl</servlet-name> <url-pattern>/servletFourImpl</url-pattern></servlet-mapping>
  • API用法
public class ServletFourImpl extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=utf-8") ; response.setCharacterEncoding("UTF-8"); response.setStatus(200) ; response.getWriter().print("Hello,知了"); }}3、转发和重定向
  • 转发
服务器端进行的页面跳转的控制 ;
request.getRequestDispatcher("/转发地址").forward(request, response);
  • 重定向
服务端响应跳转信息 , 浏览器端进行的页面跳转 ;
response.sendRedirect("重定向地址");
  • 转发和重定向对比

JavaEE编程基础:Servlet核心API用法详解

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JavaEE编程基础:Servlet实现方式 , 生命周期过程
JavaEE编程基础:Servlet核心API用法详解

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【JavaEE编程基础:Servlet核心API用法详解】


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