jsp+servlet+javabean开发web项目
Posted hackxiyu
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jsp+servlet+javabean开发web项目相关的知识，希望对你有一定的参考价值。
一.介绍：
项目依赖包：jdbc数据库包
jsp+servlet+javabean开发web项目，是最接近web项目原生运行原理的。
但是，jsp内容混乱，项目结构复杂时，代码会混乱
二.运行原理：
jsp发出请求到web--
web接收请求并匹配请求对应的servlet--
servlet调用数据库dao层操作数据库--
如果有数据传递，放到request或者session中
重点：servlet会执行doService()方法来判断调用doGet()或者doPost()
三.开发步骤：
1.新建web项目
2.新建实体类 User.java
1 package com.mart.bean; 2 3 public class User { 4 5 //属性 6 private Integer id; 7 private String uname; 8 private String upass; 9 private String tname; 10 private String utype; 11 //属性访问 12 public Integer getId() { 13 return id; 14 } 15 public void setId(Integer id) { 16 this.id = id; 17 } 18 public String getUname() { 19 return uname; 20 } 21 public void setUname(String uname) { 22 this.uname = uname; 23 } 24 public String getUpass() { 25 return upass; 26 } 27 public void setUpass(String upass) { 28 this.upass = upass; 29 } 30 public String getTname() { 31 return tname; 32 } 33 public void setTname(String tname) { 34 this.tname = tname; 35 } 36 public String getUtype() { 37 return utype; 38 } 39 public void setUtype(String utype) { 40 this.utype = utype; 41 } 42 43 //构造 44 public User() { 45 super(); 46 // TODO Auto-generated constructor stub 47 } 48 public User(Integer id, String uname, String upass, String tname, 49 String utype) { 50 super(); 51 this.id = id; 52 this.uname = uname; 53 this.upass = upass; 54 this.tname = tname; 55 this.utype = utype; 56 } 57 public User(String uname, String upass, String tname, String utype) { 58 super(); 59 this.uname = uname; 60 this.upass = upass; 61 this.tname = tname; 62 this.utype = utype; 63 } 64 //更新操作改善,不加name更新 65 public User(Integer id, String upass, String tname, String utype) { 66 super(); 67 this.id = id; 68 this.upass = upass; 69 this.tname = tname; 70 this.utype = utype; 71 } 72 73 //tostring 74 @Override 75 public String toString() { 76 return "User [id=" + id + ", uname=" + uname + ", upass=" + upass 77 + ", tname=" + tname + ", utype=" + utype + "]"; 78 } 79 80 81 }
3.编写操作接口 UserDao.java
package com.mart.dao; import java.util.List; import com.mart.bean.User; public interface UserDao { /** * @param u 待添加的用户 * @return 0-添加失败 1-添加成功 */ public Integer addUser(User u); /** * @param id 待删除用户编号 * @return 0-删除失败 1-删除成功 */ public Integer delUser(Integer id); /** * @param u 要添加的用户 * @return 0-更新失败 1-更新成功 */ public Integer updUser(User u); /** * @param id 待查找的用户编号 * @return 要查找的用户 */ public User findUserById(Integer id); /** * @return 全部用户列表 */ public List<User> FindAllUser(); }
4.编写数据库操作工具类 DBUtil.java
package com.mart.util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class DBUtil { //获取oracle数据库连接 public Connection getCurrentConnection(){ //初始返回值 Connection conn = null; try { //加载驱动 Class.forName("oracle.jdbc.driver.OracleDriver"); conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl", "mart", "java"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } }
5.编写接口实现 UserDaoImpl.java
package com.mart.dao.impl; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.mart.bean.User; import com.mart.dao.UserDao; import com.mart.util.DBUtil; public class UserDaoImpl implements UserDao{ @Override public Integer addUser(User u) { // TODO Auto-generated method stub int res=-1; //连接数据库 DBUtil dbUtil = new DBUtil(); Connection conn = dbUtil.getCurrentConnection(); //添加语句 PreparedStatement ps = null; String sql = "insert into mart_user values(seq_mart_user.nextval,?,?,?,?)"; try { ps = conn.prepareStatement(sql); ps.setString(1, u.getUname()); ps.setString(2, u.getUpass()); ps.setString(3, u.getTname()); ps.setString(4, u.getUtype()); //执行 res = ps.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(ps!=null)ps.close(); if(conn!=null)conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return res; } @Override public Integer delUser(Integer id) { // TODO Auto-generated method stub int res=-1; //连接数据库 DBUtil dbUtil = new DBUtil(); Connection conn = dbUtil.getCurrentConnection(); //删除语句 PreparedStatement ps = null; String sql = "delete from mart_user where id=?"; try { ps = conn.prepareStatement(sql); ps.setInt(1, id); //执行 res = ps.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(ps!=null)ps.close(); if(conn!=null)conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return res; } @Override public Integer updUser(User u) { // TODO Auto-generated method stub int res=-1; //连接数据库 DBUtil dbUtil = new DBUtil(); Connection conn = dbUtil.getCurrentConnection(); //更新语句 PreparedStatement ps = null; String sql = "update mart_user set upass=?,tname=?,utype=? where id=?"; try { ps = conn.prepareStatement(sql); // ps.setString(1, u.getUname());--完善更改，不设置名字 ps.setString(1, u.getUpass()); ps.setString(2, u.getTname()); ps.setString(3, u.getUtype()); ps.setInt(4, u.getId()); //执行 res = ps.executeUpdate(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(ps!=null)ps.close(); if(conn!=null)conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return res; } @Override public User findUserById(Integer id) { // TODO Auto-generated method stub User u = null; //连接数据库 DBUtil dbUtil = new DBUtil(); Connection conn = dbUtil.getCurrentConnection(); //查找语句 PreparedStatement ps = null; ResultSet rs = null; String sql = "select * from mart_user where id=?"; try { ps = conn.prepareStatement(sql); ps.setInt(1, id); //获取结果 rs = ps.executeQuery(); rs.next(); u = new User(rs.getInt("id"), rs.getString("uname"), rs.getString("upass"), rs.getString("tname"), rs.getString("utype")); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(rs!=null)rs.close(); if(ps!=null)ps.close(); if(conn!=null)conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return u; } @Override public List<User> FindAllUser() { // TODO Auto-generated method stub List<User> uList = new ArrayList<User>(); //连接数据库 DBUtil dbUtil = new DBUtil(); Connection conn = dbUtil.getCurrentConnection(); //查找语句 PreparedStatement ps = null; ResultSet rs = null; String sql = "select * from mart_user"; try { ps = conn.prepareStatement(sql); rs = ps.executeQuery(); //获取结果 while(rs.next()){ uList.add(new User(rs.getInt("id"), rs.getString("uname"), rs.getString("upass"), rs.getString("tname"), rs.getString("utype"))); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(rs!=null)rs.close(); if(ps!=null)ps.close(); if(conn!=null)conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return uList; } }
6.编写测试文件，测试是否底层数据操作成功 UserTest.java
package com.mart.test; import java.util.ArrayList; import java.util.List; import com.mart.bean.User; import com.mart.dao.impl.UserDaoImpl; public class UserTest { //主测试 public static void main(String[] args) { //实例化实现 UserDaoImpl udi = new UserDaoImpl(); // addTest(udi); // delTest(udi); // updTest(udi); // findTest(udi); // findAllTest(udi); } //添加测试 private static void addTest(UserDaoImpl udi){ //设置添加对象 User u = new User("wangwu", "0002", "王五", "0"); Integer res = udi.addUser(u); if(res>0){ System.out.println("添加成功"); }else{ System.out.println("添加失败"); } } //删除测试 private static void delTest(UserDaoImpl udi){ //设置删除编号 int id = 2; int res = udi.delUser(id); if(res>0){ System.out.println("删除成功"); }else{ System.out.println("删除失败"); } } //更新测试 private static void updTest(UserDaoImpl udi){ //设置更新对象 User u = new User(9, "tiqi", "123", "田七", "0"); Integer res = udi.updUser(u); if(res>0){ System.out.println("更新成功"); }else{ System.out.println("更新失败"); } } //id查找测试 private static void findTest(UserDaoImpl udi){ //设置查找id int id = 6; User u =udi.findUserById(id); System.out.println(u); } //全部查找 private static void findAllTest(UserDaoImpl udi){ //新建保存集 List<User> uList = new ArrayList<User>(); uList = udi.FindAllUser(); for (User user : uList) { System.out.println(user); } } }
7.编写jsp显示界面,仅以用户显示界面为例 show.jsp
<%@page import="com.mart.bean.User"%> <%@page import="com.mart.dao.impl.UserDaoImpl"%> <%@page import="com.mart.dao.UserDao"%> <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <html> <head> <title>用户显示</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> </head> <body> <div class="top" style="width: 800px;height: 50px"> <h3>用户显示界面</h3> </div> <div class="center" style="width: 800px;height: auto;"> <table border="1"> <tr> <th>用户编号</th> <th>用户账户</th> <th>用户密码</th> <th>真实名字</th> <th>用户类型</th> <th>用户操作</th> </tr> <tr> <% //实例化接口 UserDao udi = new UserDaoImpl(); List<User> uList = new ArrayList<User>(); uList = udi.FindAllUser(); for(User u : uList){ %> <tr> <td> <%=u.getId() %> </td> <td> <%=u.getUname() %> </td> <td> <%=u.getUpass() %> </td> <td> <%=u.getTname() %> </td> <td> <%=u.getUtype().equals("0")?"普通":"管理员" %> </td> <td> <a href="upd.jsp?id=<%=u.getId() %>&uname=<%=u.getUname()%>& upass=<%=u.getUpass() %>&tname=<%=u.getTname()%>& utype=<%=u.getUtype() %>">更新</a> /<a href="../del.do?id=<%=u.getId() %>">删除</a> </td> </tr> <% } %> </JavaWeb实现用户登录注册功能实例代码(基于Servlet+JSP+JavaBean模式)