servlet+jsp 实现一个简单的web项目
Posted
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了servlet+jsp 实现一个简单的web项目相关的知识，希望对你有一定的参考价值。
开发环境：
MyEclipse 10.7
Tomcat 7
mysql 5.5
开发过程
1. 建立一个 Web Project，名字为 MyProject，如下图，点击finish,就创建好了。
2. 修改项目编码为Utf-8，在src下创建类，首先 看一下项目结构
2.1 创建实体类类 User
package entity;
public class User {
private String id;
private String name;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
2.2 创建jdbc 连接及数据库的表，在这里要记得把数据库的 jar 加上，我用的mySql，把mysql-connector-java.jar 加到lib下。
package util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class Jdbc {
//连接
public static Connection connect()throws SQLException, ClassNotFoundException{
Connection conn = null;
Class.forName("com.mysql.jdbc.Driver");
//取得连接的url,能访问MySQL数据库的用户名,密码；user：数据库表名
String url = "jdbc:mysql://localhost:3306/user";
String username = "root";
String password = "root";
conn =(Connection) DriverManager.getConnection(url, username, password);
return conn;
}
//关闭
public static void close(Statement stat, Connection conn) throws SQLException{
if(stat != null){
stat.close();
}
if(conn != null){
conn.close();
}
}
}
2.3 修改 url 、用户名和密码，在这里可以直接用main方法测试是否连接成功。写UserDao，这里只写了一个查询。
package dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import entity.User;
import util.Jdbc;
public class UserDao {
public ArrayList<User> search(String id) throws ClassNotFoundException, SQLException{
Connection con = Jdbc.connect();
Statement sta = null;
ResultSet rs = null;
sta = (Statement) con.createStatement();
ArrayList<User> users = new ArrayList<User>();
rs = (ResultSet) sta.executeQuery("select * from T_USER where Id = ‘"+id+"‘");
while(rs.next()){
User u = new User();
u.setId(rs.getString("idNumber"));
u.setName(rs.getString("name"));
users.add(u);
}
if(rs != null){
rs.close();
}
Jdbc.close(sta, con);
return users;
}
}
2.4 写 ActionServlet。直接创建Servlet方便一些。
package web;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import dao.UserDao;
import entity.User;
public class ActionServlet extends HttpServlet {
public void service(HttpServletRequest request,HttpServletResponse response)throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
String uri = request.getRequestURI();
uri = uri.substring(uri.indexOf("MyProject/") + 10, uri.lastIndexOf("."));
if(uri.equals("show")){
try {
show(request,response);
} catch (Exception e) {
e.printStackTrace();
}
}
}
// 查看列表
public void show(HttpServletRequest request, HttpServletResponse response)
throws Exception {
String id = request.getParameter("id");
//根据id查询
List<User> userList = new UserDao().search(id);
//返回页面
request.setAttribute("userList", userList);
request.getRequestDispatcher("record.jsp").forward(request, response);
}
}
2.5 修改web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
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_2_5.xsd">
<display-name></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>ActionServlet</servlet-name>
<servlet-class>web.ActionServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ActionServlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
3.这样后台就写完了，下面开始写jsp页面。
修改 index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="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>
</head>
<body>
<div>
<form action="show.do" method="post">
ID：<input type="text" id="id" name="id" size="18"/>
<input type="submit" value="提交"/>
</form>
</div>
</body>
</html>
4. 添加 record.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ page import ="entity.User" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP ‘index.jsp‘ starting page</title>
<style type="text/css">
td{
border:1px solid #89c3eb;
width:200px;
height:30px;
text-align:center;
margin:0px;
padding:0px;
}
tr{
margin:0px;
padding:0px;
}
</style>
</head>
<body>
<div>
人员信息<br/>
<%
List<User> lists =(ArrayList)request.getAttribute("userList");
if(lists.size() == 0){
out.print("无查询记录");
}else{
out.print("<table cellspacing=‘0px‘ cellpadding=‘0px‘>");
out.print("<tr><td>姓名</td><td>ID</td></tr>");
for(int i=0;i<lists.size();i++){
User u = lists.get(i);
out.print("<tr>");
out.print("<td>"+u.getName()+"</td>");
out.print("<td>"+u.getId()+"</td>");
out.print("</tr>");
}
out.print("</table>");
}
%>
</div>
</body>
</html>
5. 部署程序到tomcat，在浏览器访问地址 http://localhost:8080/MyProject/ 可以看到index.jsp的内容，输入Id提交就能看到数据了。
以上是关于servlet+jsp 实现一个简单的web项目的主要内容，如果未能解决你的问题，请参考以下文章
web项目总结——通过jsp+servlet实现对oracle的增删改查功能