一个简单jsp-servlet例子

以下的简单 jsp-servlet 例子流程为：

index.jsp 提交一个 form 表单， tomcat 容器根据 form 中所定义的 action 从 web.xml 找到与之响应的 servlet ： Hello.java ，根据 form 中定义的 method 找到 servlet 处理该请求的方法： doPost() ，调用该方法做一定的逻辑处理之后，跳转到另一个页面： result.jsp ；

 

 以下为源码：

Hello.java

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import java.io.IOException;  
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
public class Hello extends HttpServlet {  
    /** 
     * Constructor of the object. 
     */ 
    public Hello() {  
       super();  
       System.out.println("new Hello");  
    }  
    /** 
     * Destruction of the servlet. <br> 
     */ 
    public void destroy() {  
       super.destroy(); // Just puts "destroy" string in log  
       // Put your code here  
       System.out.println("destroy");  
    }  
    /** 
     * 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 {         
       String text1 = request.getParameter("text1");  
            String str = text1;  
            response.sendRedirect("result.jsp?text1=" + text1);     
}  
    /** 
     * 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 {  
           doGet(request,response);  
    }  
    /** 
     * Initialization of the servlet. <br> 
     * @throws ServletException if an error occure 
     */ 
    public void init() throws ServletException {  
       // Put your code here  
        System.out.println("init");  
    }  
} 
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Hello extends HttpServlet {
    /**
     * Constructor of the object.
     */
    public Hello() {
       super();
       System.out.println("new Hello");
    }
    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
       super.destroy(); // Just puts "destroy" string in log
       // Put your code here
       System.out.println("destroy");
    }
    /**
     * 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 {     
       String text1 = request.getParameter("text1");
      String str = text1;
      response.sendRedirect("result.jsp?text1=" + text1);  
}
    /**
     * 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 {
           doGet(request,response);
    }
    /**
     * Initialization of the servlet. <br>
     * @throws ServletException if an error occure
     */
    public void init() throws ServletException {
       // Put your code here
     System.out.println("init");
    }
}
 

 

index.jsp

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<%@ page language="java" pageEncoding="UTF-8"%> 
<html> 
<head> 
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 
    <title>hello</title> 
</head> 
<body> 
    <form action="myForm" method="post"> 
        <input type="text" name="text1" value="China"> 
        <input type="submit" value="submit  myForm"> 
    </form> 
</body> 
</html> 
<%@ page language="java" pageEncoding="UTF-8"%>
<html>
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 <title>hello</title>
</head>
<body>
 <form action="myForm" method="post">
  <input type="text" name="text1" value="China">
  <input type="submit" value="submit  myForm">
 </form>
</body>
</html>
 

 

result.jsp

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<%@ page language="java" pageEncoding="UTF-8"%> 
<html> 
<head> 
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 
    <title>result</title> 
</head> 
<body> 
    hello: <%= request.getParameter("text1") %> 
</body> 
</html> 
<%@ page language="java" pageEncoding="UTF-8"%>
<html>
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
 <title>result</title>
</head>
<body>
 hello: <%= request.getParameter("text1") %>
</body>
</html>
 

 

web.xml

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<?xml version="1.0" encoding="utf-8"?> 
<web-app version="2.4" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee  
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> 
  <servlet> 
    <servlet-name>hello</servlet-name> 
    <servlet-class>Hello</servlet-class> 
  </servlet> 
  <servlet-mapping> 
    <servlet-name>hello</servlet-name> 
    <url-pattern>/myForm</url-pattern> 
  </servlet-mapping> 
  <welcome-file-list> 
    <welcome-file>index.jsp</welcome-file> 
  </welcome-file-list> 
</web-app>