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
}
}