java servlet 代码样例 （demo）

时间：2022-03-23 12:54:26

今天又搞了下jsp +servlet 的代码样例，感觉虽然搭了好多次，可是每次还是不记得那些参数，都要去网上搜索，索性自己把这次的简单demo给记录下来，供下次使用的时候直接复制吧。

这个web逻辑 input.jsp ---->ReportServlet -->output.jsp (在servlet中输入值，将参数传递到output.jsp中)

整个文档目录结构如下：

java servlet 代码样例 （demo）

相关代码如下：

input.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

<title>Insert title here</title>

</head>

<body>

<form method="post" action="report" >

	<p> seller_id</p>

	<input type="text" name="seller_id"></input>

	<label for="from_date">from_date:</label>

    <input type="text" id="from_date" name="from_date" />

    <label for="end_date">end_date:</label>

    <input type="text" id="end_date" name="end_date" />

    <input type="submit" id="submit" name="submit" />

</form>

</body>

</html>

output.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<%@ page import="java.util.*"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

<title>Insert title here</title>

</head>

<body>

<%

    List<String> result =(List)request.getAttribute("result");

%>

 <table>

 <%

     for(String str:result)

    {

%>

<tr>

    <td>

    <%=str+"\n" %>

    </td>

</tr>

<%} %>

 </table>

</body>

</html>

web.xml(主要是注意servlet配置)

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 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>Report</display-name>
  <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>
  
  <servlet>
        <servlet-name>reportServlet</servlet-name>
        <servlet-class>cn.edu.ReportServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>reportServlet</servlet-name>
        <url-pattern>/report</url-pattern>
    </servlet-mapping>
    
</web-app>

ReportServlet.java 内容

package cn.edu;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

public class ReportServlet extends HttpServlet{

    public void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {  

        doPost(request,response);

    }  

    public void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

            String from_date = request.getParameter("from_date");

            System.out.println(from_date);

            List <String> result = new ArrayList<String>();

            result.add("apple");

            result.add("apple");

            result.add("apple");

            result.add("apple");

            //HttpSession session=request.getSession();

            request.setAttribute("result", result);

            request.getRequestDispatcher("output.jsp").forward(request,response);

            //return ;

            //response.sendRedirect("/Report/output.jsp");

            //request.

            //response.sendRedirect(arg0)

//        response.setContentType("text/html;charset=utf-8");

//        PrintWriter out = response.getWriter();

//        request.setCharacterEncoding("utf-8");

//        out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");

//        out.println("<HTML>");

//        out.println("  <HEAD><TITLE>display survey information</TITLE></HEAD>");

//        out.println("  <BODY>");

//        out.println("<h2>用户输入的信息</h2>");

//        out.println("用户名:"+request.getParameter("name")+"<br>");

//        out.println("e-mail:"+request.getParameter("email")+"<br>");

//        out.println("年纪："+request.getParameter("age")+"<br>");

//        out.println("编程时间："+request.getParameter("codetime")+"<br>");

//        out.println("你使用的操作系统：");

//        printValues(out,request.getParameterValues("os"));

//        out.println("你使用的编程语言：");

//        printValues(out,request.getParameterValues("language"));

//        out.println("建议："+request.getParameter("comment")+"<br>");

//        out.println("  </BODY>");

//        out.println("</HTML>");

//        out.flush();

//        out.close();

    }  

    public void printValues(PrintWriter out,String[] values){

        if(values==null || values.length==0)

            return;

        out.println("<ul>");

        for(int i=0;i<values.length;i++){

            out.println("<li>"+values[i]+"</li>");

        }

        out.println("</ul>");

    }

}

好了，就这样了，祝学习web的朋友们好运。

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