时间:2023-08-29 05:54:01 | 来源:网站运营
时间:2023-08-29 05:54:01 来源:网站运营
手把手搭建一个完整的javaweb项目(适合新手):手把手搭建一个完整的javaweb项目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', '杭州', '123123');
这里使用到了navicat for mysql 这是一种mysql的图形界面化工具,后期可以非常方便的操作数据库。需要的童鞋 给你们个连接 点击链接加入群【JAVA资料分享群】:正在跳转2.然后打开MyEclipse新建一个web项目
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"); //将编码改为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><!--全路径 从根包开始一直到类名--> </filter> <filter-mapping> <filter-name>EncodingFilter</filter-name> <url-pattern>/*</url-pattern> <!--*即为过滤所有--> </filter-mapping> <welcome-file-list> <welcome-file>denglu.jsp</welcome-file> </welcome-file-list> </web-app>
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(实体即抽象出来的用户对象,对应数据库中的user表,表中每个字段在实体中为一个属性,也可以理解为一个User对象对应数据库中的user表一条记录)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(使用接口类是为了规范开发)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 }
新建UserDaoImpl.java 实现UserDao接口,及未实现的方法 (SQL语句建议在mysql中测试以下,没有问题然后在拿到实现类中使用,可以避免无必要的麻烦)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(Servlet有两种方式创建,一种手工创建。另一种程序自动生成。前者自己创建java类,实现Servlet具体内容,然后需要去WEB_INF下的web.xml去配置servlet . 而后者则直接由程序替我们配置好了Servlet)本例子使用第二种方式生成Servletpackage 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 { //需要继承HttpServlet 并重写doGet doPost方法 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); //将信息使用doPost方法执行 对应jsp页面中的form表单中的method } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String name = request.getParameter("name"); //得到jsp页面传过来的参数 String pwd = request.getParameter("pwd"); UserDao ud = new UserDaoImpl(); if(ud.login(name, pwd)){ request.setAttribute("xiaoxi", "欢迎用户"+name); //向request域中放置信息 request.getRequestDispatcher("/success.jsp").forward(request, response);//转发到成功页面 }else{ response.sendRedirect("index.jsp"); //重定向到首页 } } }
有两点要注意的地方: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"); //获取jsp页面传过来的参数 String pwd = request.getParameter("pwd"); String sex = request.getParameter("sex"); String home = request.getParameter("home"); String info = request.getParameter("info"); User user = new User(); //实例化一个对象,组装属性 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); //向request域中放置参数 //request.setAttribute("xiaoxi", "注册成功"); request.getRequestDispatcher("/denglu.jsp").forward(request, response); //转发到登录页面 }else{ response.sendRedirect("index.jsp");//重定向到首页 } } }
12.在servlet下创建SearchallServlet用来返回数据库中所有用户信息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); } }
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"); } } }
<?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><!--过滤器配置--> <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类路径配置--> <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类映射配置--> <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><!--默认首页地址--> <welcome-file>denglu.jsp</welcome-file> </welcome-file-list> </web-app>
16.新建jsp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 用户注册页面<%@ 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="杭州">杭州</option> <option value="杭州" selected>杭州</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 失败页面<%@ 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 成功页面${xiaoxi}为EL表达式 获取request域中的键名为xiaoxi的值<%@ 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> ${xiaoxi} <br> <a href="Searchall">查看所有用户</a> </body> </html>
showall.jsp 展现所有用户页面<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>所有用户页面</title> </head> <body> <h1>${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>
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