手把手搭建一个完整的javaweb项目(适合新手)

一年多没接触javaweb了，有些知识感觉有些生疏，所以重新做一个简单的javaweb项目用来回忆旧的知识点。

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用MyEclipse和mysql搭建

1.首先打开mysql数据库 新建一个数据库test，然后生成对应的表结构

CREATE TABLE `user` (  `id` int(11) NOT NULL auto_increment,  `name` varchar(255) NOT NULL,  `pwd` varchar(255) NOT NULL,  `sex` varchar(255) NOT NULL,  `home` varchar(255) NOT NULL,  `info` varchar(255) NOT NULL,  PRIMARY KEY  (`id`)) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;INSERT INTO `user` VALUES ('3', '123', '123', '123', '123', '123');INSERT INTO `user` VALUES ('4', '123123', '123123', '男', '北京', '123123');

2.然后打开MyEclipse新建一个web项目

3.在webroot下的WEB-INF下的lib中导入mysql的驱动jar包

4.建立对应的包结构 
com.filter   //过滤器 解决中文字符集乱码
com.util     //数据库连接工具类
com.entity   //实体类
com.dao      //数据操作类
com.servlet   //servlet类
5.在filter下新建一个EncodingFilter用来解决中文字符集乱码，它需要继承Filter接口

package com.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;public class EncodingFilter implements Filter{public EncodingFilter(){System.out.println("过滤器构造");}public void destroy() {System.out.println("过滤器销毁");}public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=utf-8");chain.doFilter(request, response);}public void init(FilterConfig arg0) throws ServletException {System.out.println("过滤器初始化");}}

6.到web.xml下进行对EncodingFilter相应的配置

<?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>    <filter>  <filter-name>EncodingFilter</filter-name>  <filter-class>com.filter.EncodingFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>EncodingFilter</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>      <welcome-file-list>    <welcome-file>denglu.jsp</welcome-file>  </welcome-file-list></web-app>

7.在util下新建一个DBconn类用来处理对数据库的连接操作

package com.util;import java.sql.*;public class DBconn {static String url = "jdbc:mysql://localhost:3306/test?useunicuee=true& characterEncoding=utf8"; static String username = "root"; static String password = "root"; static Connection  conn = null;static ResultSet rs = null;static PreparedStatement ps =null;public static void init(){try {Class.forName("com.mysql.jdbc.Driver");conn = DriverManager.getConnection(url,username,password);} catch (Exception e) {System.out.println("init [SQL驱动程序初始化失败！]");e.printStackTrace();}}public static int addUpdDel(String sql){int i = 0;try {PreparedStatement ps =  conn.prepareStatement(sql);i =  ps.executeUpdate();} catch (SQLException e) {System.out.println("sql数据库增删改异常");e.printStackTrace();}return i;}public static ResultSet selectSql(String sql){try {ps =  conn.prepareStatement(sql);rs =  ps.executeQuery(sql);} catch (SQLException e) {System.out.println("sql数据库查询异常");e.printStackTrace();}return rs;}public static void closeConn(){try {conn.close();} catch (SQLException e) {System.out.println("sql数据库关闭异常");e.printStackTrace();}}}

8.在entity下新建一个User实体类

package com.entity;public class User {    private int id;    private String name;    private String pwd;    private String sex;    private String home;    private String info;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getPwd() {return pwd;}public void setPwd(String pwd) {this.pwd = pwd;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getHome() {return home;}public void setHome(String home) {this.home = home;}public String getInfo() {return info;}public void setInfo(String info) {this.info = info;}    }

9.在dao下新建一个UserDao接口  以及对应的方法实现类

UserDao.java

package com.dao;import java.util.List;import com.entity.User;public interface UserDao {public boolean login(String name,String pwd);//登录public boolean register(User user);//注册public List<User> getUserAll();//返回用户信息集合public boolean delete(int id) ;//根据id删除用户public boolean update(int id,String name, String pwd,String sex, String home,String info) ;//更新用户信息}

UserDaoImpl.java

package com.dao;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import com.entity.User;import com.util.DBconn;public class UserDaoImpl implements UserDao{public boolean register(User user) {boolean flag = false;DBconn.init();int i =DBconn.addUpdDel("insert into user(name,pwd,sex,home,info) " +"values('"+user.getName()+"','"+user.getPwd()+"','"+user.getSex()+"','"+user.getHome()+"','"+user.getInfo()+"')");if(i>0){flag = true;}DBconn.closeConn();return flag;}    public boolean login(String name, String pwd) {boolean flag = false;try {    DBconn.init();ResultSet rs = DBconn.selectSql("select * from user where name='"+name+"' and pwd='"+pwd+"'");while(rs.next()){if(rs.getString("name").equals(name) && rs.getString("pwd").equals(pwd)){flag = true;}}DBconn.closeConn();} catch (SQLException e) {e.printStackTrace();}return flag;}public List<User> getUserAll() {List<User> list = new ArrayList<User>();    try {    DBconn.init();ResultSet rs = DBconn.selectSql("select * from user");while(rs.next()){User user = new User();user.setId(rs.getInt("id"));user.setName(rs.getString("name"));user.setPwd(rs.getString("pwd"));user.setSex(rs.getString("sex"));user.setHome(rs.getString("home"));user.setInfo(rs.getString("info"));list.add(user);}DBconn.closeConn();return list;} catch (SQLException e) {e.printStackTrace();}return null;}public boolean update(int id,String name, String pwd,String sex, String home,String info) {boolean flag = false;DBconn.init();String sql ="update user set name ='"+name+"' , pwd ='"+pwd+"' , sex ='"+sex+"' , home ='"+home+"' , info ='"+info+"' where id = "+id;int i =DBconn.addUpdDel(sql);if(i>0){flag = true;}DBconn.closeConn();return flag;}public boolean delete(int id) {boolean flag = false;DBconn.init();String sql = "delete  from user where id="+id;int i =DBconn.addUpdDel(sql);if(i>0){flag = true;}DBconn.closeConn();return flag;}    }

10.在servlet下创建DengluServlet用来实现对用户登录的操作

DengluServlet.java

package com.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;import com.dao.UserDao;import com.dao.UserDaoImpl;public class DengluServlet 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 name = request.getParameter("name");String pwd = request.getParameter("pwd");UserDao ud = new UserDaoImpl();if(ud.login(name, pwd)){request.setAttribute("xiaoxi", "欢迎用户"+name);request.getRequestDispatcher("/success.jsp").forward(request, response);}else{response.sendRedirect("index.jsp");}}}

11.在servlet下创建一个ZhuceServlet用来实现用户注册的操作

ZhuceServlet.java

package com.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;import com.dao.UserDao;import com.dao.UserDaoImpl;import com.entity.User;public class ZhuceServlet 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 name = request.getParameter("name");String pwd = request.getParameter("pwd");String sex = request.getParameter("sex");String home = request.getParameter("home");String info = request.getParameter("info");User user = new User();user.setName(name);user.setPwd(pwd);user.setSex(sex);user.setHome(home);user.setInfo(info);UserDao ud = new UserDaoImpl();if(ud.register(user)){request.setAttribute("username", name);//request.setAttribute("xiaoxi", "注册成功");request.getRequestDispatcher("/denglu.jsp").forward(request, response);}else{response.sendRedirect("index.jsp");}}}

12.在servlet下创建SearchallServlet用来返回数据库中所有用户信息

Searchall.java

package com.servlet;import java.io.IOException;import java.io.PrintWriter;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.dao.UserDao;import com.dao.UserDaoImpl;import com.entity.User;public class Searchall 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 {UserDao ud = new UserDaoImpl();List<User> userAll = ud.getUserAll();request.setAttribute("userAll", userAll);request.getRequestDispatcher("/showall.jsp").forward(request, response);}}

13.在servlet下创建DeleteServlet用来删除用户操作

DeleteServlet.java

package com.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;import com.dao.UserDao;import com.dao.UserDaoImpl;public class DeleteServlet 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 id = request.getParameter("id");int userId = Integer.parseInt(id);UserDao ud = new UserDaoImpl();if(ud.delete(userId)){request.setAttribute("xiaoxi", "删除成功");request.getRequestDispatcher("/Searchall").forward(request, response);}else{response.sendRedirect("index.jsp");}}}

14.在servlet下创建UpdateServlet操作用来更新用户信息

UpdateServlet.java

package com.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;import com.dao.UserDao;import com.dao.UserDaoImpl;import com.entity.User;public class UpdateServlet 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 id = request.getParameter("id");int userId = Integer.parseInt(id);String name = request.getParameter("name");String pwd = request.getParameter("pwd");String sex = request.getParameter("sex");String home = request.getParameter("home");String info = request.getParameter("info");System.out.println("------------------------------------"+userId);UserDao ud = new UserDaoImpl();if(ud.update(userId, name, pwd, sex, home, info)){request.setAttribute("xiaoxi", "更新成功");request.getRequestDispatcher("/Searchall").forward(request, response);}else{response.sendRedirect("index.jsp");}}}

15.配置servlet       如果非手打而用MyEclipse生成则不用配置  附完整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>    <filter>  <filter-name>EncodingFilter</filter-name>  <filter-class>com.filter.EncodingFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>EncodingFilter</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>        <servlet>    <servlet-name>DengluServlet</servlet-name>    <servlet-class>com.servlet.DengluServlet</servlet-class>  </servlet>  <servlet>    <servlet-name>ZhuceServlet</servlet-name>    <servlet-class>com.servlet.ZhuceServlet</servlet-class>  </servlet>  <servlet>    <servlet-name>Searchall</servlet-name>    <servlet-class>com.servlet.Searchall</servlet-class>  </servlet>  <servlet>    <servlet-name>DeleteServlet</servlet-name>    <servlet-class>com.servlet.DeleteServlet</servlet-class>  </servlet>  <servlet>    <servlet-name>UpdateServlet</servlet-name>    <servlet-class>com.servlet.UpdateServlet</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>DengluServlet</servlet-name>    <url-pattern>/DengluServlet</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>ZhuceServlet</servlet-name>    <url-pattern>/ZhuceServlet</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>Searchall</servlet-name>    <url-pattern>/Searchall</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>DeleteServlet</servlet-name>    <url-pattern>/DeleteServlet</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>UpdateServlet</servlet-name>    <url-pattern>/UpdateServlet</url-pattern>  </servlet-mapping>        <welcome-file-list>    <welcome-file>denglu.jsp</welcome-file>  </welcome-file-list></web-app>

16.新建jsp页面

denglu.jsp默认页面进入项目后  先进入该页面

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>登录注册页面</title>  </head>  <body >     <form action="DengluServlet"  method="post"  style="padding-top:-700px;">用户名：<input type="text" name="name"value=""><br><br> 密码：<input type="password" name="pwd"value=""><br><br>        <input type="submit"value="登录"name="denglu"><input type="reset"value="重置"><br> </form> <form action="zhuce.jsp"> <input type="submit"value="新用户注册">     </form>      </body></html>

zhuce.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>    <title>My JSP 'BB.jsp' starting page</title>  </head>  <body >  <form action="ZhuceServlet"method="post" style="padding-top:-700px;">   输入用户名:<input name="name" type="text"><br><br>   输入密码:<input name="pwd" type="password"><br><br>   选择性别:<input type="radio"name="sex"value="男"checked>男        <input type="radio"name="sex"value="女">女<br><br>   选择家乡:   <select name="home">   <option value="上海">上海</option>   <option value="北京" selected>北京</option>   <option value="纽约">纽约</option>   </select><br>               填写个人信息:<br>   <textarea name="info" row="5"cols="30"></textarea><br>   <input type="reset"value="重置"><input type="submit"value="注册">   </form>  </body></html>

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>    <title>My JSP 'index.jsp' starting page</title>  </head>  <body>    <h1>失敗</h1>  </body></html>

success.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>    <title>My JSP 'success.jsp' starting page</title>  </head>  <body>${xiaoxi} <br>  <a href="Searchall">查看所有用户</a>  </body></html>

showall.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <%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>所有用户页面</title>  </head>    <body>  <h1>${xiaoxi}</h1>  <table  width="600" border="1" cellpadding="0" >  <tr>  <th>ID</th>  <th>姓名</th>  <th>性别</th>  <th>密码</th>  <th>家乡</th>  <th>备注</th>  <th>操作</th>  </tr>     <c:forEach var="U" items="${userAll}"  >       <form action="UpdateServlet" method="post">        <tr>       <td><input type="text" value="${U.id}" name="id" ></td>       <td><input type="text" value="${U.name}" name="name"></td>       <td><input type="text" value="${U.sex}" name="sex"></td>       <td><input type="text" value="${U.pwd}" name="pwd"></td>       <td><input type="text" value="${U.home}" name="home"></td>       <td><input type="text" value="${U.info}" name="info"></td>       <td><a href="DeleteServlet?id=${U.id}">删除</a>  <input type="submit" value="更新"/></td>   </tr>    </form>     </c:forEach>      </table>  </body></html>