javaWeb之servlet路径跳转

时间:2022-04-02 13:36:32

javaWeb之servlet路径跳转

javaWeb之servlet路径跳转
index.jsp:

<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %>
<% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>My JSP 'index.jsp' starting page</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!-- <link rel="stylesheet" type="text/css" href="styles.css"> -->
  </head>

  <body>
    <h1>Servlet路径跳转</h1>
    <hr>
    <!-- 使用相对路径访问HelloServlet /servlet/HelloServlet前面的“/”表示服务器的根目录,是不对的 -->

    <a href="servlet/HelloServlet">访问HelloServlet</a><br>
    <!-- http://localhost:8080/ServletPathDirection/servlet/HelloServlet -->

    <!-- 使用绝对路径访问HelloServlet path变量表示项目的根目录-->
    <a href="<%=path%>/servlet/HelloServlet">访问HelloServlet</a><br>
    <!-- 表单中action的URL地址的写法与超链接写法一样 -->

    <a href="servlet/TestServlet">访问TestServlet,跳转到Test.jsp</a>

  </body>
</html>

test.jsp:

<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %>
<% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>My JSP 'test.jsp' starting page</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!-- <link rel="stylesheet" type="text/css" href="styles.css"> -->

  </head>

  <body>
      <h1>Test.jsp</h1>
      <hr>
  </body>
</html>

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>ServletPathDirection</display-name>
  <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>HelloServlet</servlet-name>
    <servlet-class>servlet.HelloServlet</servlet-class>
  </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>TestServlet</servlet-name>
    <servlet-class>servlet.TestServlet</servlet-class>
  </servlet>


  <servlet-mapping>
    <servlet-name>HelloServlet</servlet-name>
    <url-pattern>/servlet/HelloServlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>TestServlet</servlet-name>
    <url-pattern>/servlet/TestServlet</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

HelloServlet.java:

package servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class HelloServlet extends HttpServlet {

    /** * Constructor of the object. */
    public HelloServlet() {
        super();
    }

    /** * Destruction of the servlet. <br> */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /** * The doGet method of the servlet. <br> * * 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 {

        doPost(request,response);
    }

    /** * The doPost method of the servlet. <br> * * 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;charset=utf-8");
        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.println("<h1>你好,我是HElloServlet</h1>");
        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 here
    }

}

TestServlet.java:

package servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestServlet extends HttpServlet {

    /** * Constructor of the object. */
    public TestServlet() {
        super();
    }

    /** * Destruction of the servlet. <br> */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /** * The doGet method of the servlet. <br> * * 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 {

        doPost(request,response);
    }

    /** * The doPost method of the servlet. <br> * * 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 {

        //请求重定向方式来提案转到test.jsp,当前路径是ServletPathDirection/servlet
        //response.sendRedirect("test.jsp");错误
        //使用request.getContextPath获得上下文对象
        //response.sendRedirect(request.getContextPath()+"/test.jsp");请求重定向

// 服务器内部跳转,这时候的"/"表示项目的根目录
// request.getRequestDispatcher("/test.jsp").forward(request,response);
        request.getRequestDispatcher("../test.jsp").forward(request,response);
    }

    /** * Initialization of the servlet. <br> * * @throws ServletException if an error occurs */
    public void init() throws ServletException {
        // Put your code here
    }

}