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 stub47 }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 //tostring74 @Override75 public String toString() {76 return "User [id=" + id + ", uname=" + uname + ", upass=" + upass77 + ", 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 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 FindAllUser() { // TODO Auto-generated method stub List uList = new ArrayList (); //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 uList = new ArrayList (); 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"%>用户显示 用户显示界面
8.编写servlet文件 ShowAction.java
package com.mart.controller;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 com.mart.bean.User;import com.mart.dao.UserDao;import com.mart.dao.impl.UserDaoImpl;public class ShowAction extends HttpServlet { //解析请求方法 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("用户展示界面：com.mart.controller.show"); //获取用户列表 UserDao udi = new UserDaoImpl(); List uList = udi.FindAllUser(); //传递用户列表到前断 //此处用session则服务器过载 request.setAttribute("uList", uList); //转到显示界面 //不能重定向，会丢失数据 response.sendRedirect("user/show.jsp"); } //响应请求方法 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /** * get和post行为相同时，直接设置内部调用即可 */ this.doGet(request, response); }}
8.在web.xml里注册servlet
淘宝商城servlet-xml配置 这是我的用户显示界面，显示全部用户 user_show ShowAction com.mart.controller.ShowAction 这是我的用户添加界面 user_add AddAction com.mart.controller.AddAction 这是我的用户删除界面 user_delete DeleteAction com.mart.controller.DeleteAction 这是我的用户更新界面 user_update UpdateAction com.mart.controller.UpdateAction ShowAction /show.do AddAction /add.do DeleteAction /del.do UpdateAction /upd.do index.jsp