Servlet 配置文件web.xml

一、配置文件如下：

  

<?xml version="1.0" encoding="UTF-8"?><web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">  <display-name></display-name><!-- 全局参数 --><context-param> <param-name>names</param-name> <param-value>游将军</param-value></context-param>  <servlet>    <description>This is the description of my J2EE component</description>    <display-name>This is the display name of my J2EE component</display-name>    <servlet-name>TestServlet</servlet-name>    <servlet-class>com.hlx.test.TestServlet</servlet-class>    <!--某一个servlet配置初始化参数 -->    <init-param>     <param-name>username</param-name>     <param-value>yjj</param-value>    </init-param>  </servlet>  <servlet>    <description>This is the description of my J2EE component</description>    <display-name>This is the display name of my J2EE component</display-name>    <servlet-name>LoginServlet</servlet-name>    <servlet-class>com.hlx.login.LoginServlet</servlet-class>  </servlet>  <!-- URL名称可以任意写 --> <servlet-mapping>    <servlet-name>TestServlet</servlet-name>    <url-pattern>/test</url-pattern>   </servlet-mapping>  <!-- <servlet-mapping>    <servlet-name>LoginServlet</servlet-name>    <url-pattern>/my/login</url-pattern>  </servlet-mapping>     <servlet-mapping>    <servlet-name>LoginServlet</servlet-name>    <url-pattern>/login.do</url-pattern>  </servlet-mapping>   -->   <servlet-mapping>    <servlet-name>LoginServlet</servlet-name>    <url-pattern>/*</url-pattern>  </servlet-mapping></web-app>

二、TestServlet页面

public class TestServlet extends HttpServlet {/** * Constructor of the object. */public TestServlet() {super();System.out.println("实例化对象！");}/** * Destruction of the servlet. <br> */public void destroy() {super.destroy(); // Just puts "destroy" string in log// Put your code hereSystem.out.println("被火化了！");}/** * The doGet method of the servlet. <br> * 相当于表单提交的默认格式：method="GET" *  * This method is called when a form has its tag value method equals to get. *  * @param request *            the request send by the client to the server * @param response *            the response send by the server to the client * @throws ServletException *             if an error occurred * @throws IOException *             if an error occurred */public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 解决乱码问题-->响应的编码response.setContentType("text/html;charset=utf-8");PrintWriter out = response.getWriter();System.out.println("处理doGet方法!");out.println("欢迎使用~==>" + this.getInitParameter("username") + "!");// 调用全局配置参数值String uname = this.getServletContext().getInitParameter("names");//out.println(uname);//保存值request.setAttribute("unames", uname);//间接跳转 -->转发//request.getRequestDispatcher("login").forward(request, response);//直接跳转-->重定向//保存值 application 全局所有的页面有效;//获得session对象HttpSession  session=  request.getSession();session.setAttribute("usession", uname);//获得application对象 全局所有的页面有效;ServletContextapplication = this.getServletContext();application.setAttribute("uapp", uname);//response.sendRedirect("login");out.println("<p/>请求路径："+request.getContextPath());out.println("<p/>请求方法："+request.getMethod());out.println("<p/>请求Addr："+request.getLocalAddr());out.println("<p/>请求post："+request.getLocalPort());out.println("<p/>请求Name："+request.getLocalName());out.println("<p/>请求Addr："+request.getRemoteAddr());out.println("<p/>请求URI："+request.getRequestURI());out.flush();out.close();}/** * The doPost method of the servlet. <br> * 表单写提交方式：method="post" *  * This method is called when a form has its tag value method equals to * post. *  * @param request *            the request send by the client to the server * @param response *            the response send by the server to the client * @throws ServletException *             if an error occurred * @throws IOException *             if an error occurred */public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("text/html");PrintWriter out = response.getWriter();out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");out.println("<HTML>");out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");out.println("  <BODY>");out.print("    This is ");out.print(this.getClass());out.println(", using the POST method");out.println("  </BODY>");out.println("</HTML>");out.flush();out.close();}/** * Initialization of the servlet. <br> *  * @throws ServletException *             if an error occurs */public void init() throws ServletException {// Put your code hereSystem.out.println("初始化！");}}