java项目分包
项目分层（分包）
view层：视图层，项目中的界面；
controller层：控制层，获取界面上的数据；将要实现的功能交给业务层处理；
service层作用: 业务层, 功能的实现, 与controller控制层和数据访问层DAO交互, 将对数据库的操作交给DAO数据访问层来处理
dao层作用: 数据访问层, 用来操作数据库表的数据
db数据库: 这里指MySQL
domain 实体包: 存放JavaBean
tools工具包:存放项目中使用到的工具类
test测试包: 存放项目功能测试的代码
各举一个例子：
view层：
package com.oracle.view;
import java.util.List;
import java.util.Scanner;
import com.oracle.controller.Sortcontroller;
import com.oracle.controller.UserController;
import com.oracle.domain.Sort;
public class Mainview {
private UserController userController = new UserController();
private Sortcontroller sortcontroller = new Sortcontroller();
public void mainShow(){
System.out.println("--------欢迎进入商城--------");
System.out.println("1、登陆");
System.out.println("2、注册");
System.out.println("3、退出");
System.out.println("请输入你的选择");
}
public void IndexShow(){
System.out.println("-------------首页-------------");
System.out.println("1、新增分类");
System.out.println("2、修改分类");
System.out.println("3、删除分类");
System.out.println("4、查询所有分类");
System.out.println("5、返回上级菜单");
System.out.println("请输入你的选择");
}
//登录页面
public void login(){
System.out.println("-----------登陆页面-------------");
System.out.println("请输入用户名：");
Scanner sc = new Scanner(System.in);
String username = sc.next();
System.out.println("请输入密码：");
String password = sc.next();
//调用Controller 层的登陆方法
int count = userController.login(username, password);
if(count > 0){
System.out.println("登陆成功！！");
run2();
}else{
System.out.println("登陆失败");
}
}
//注册页面
public void register(){
System.out.println("-----------注册页面-------------");
System.out.println("请输入用户名：");
Scanner sc = new Scanner(System.in);
String username = sc.next();
System.out.println("请输入密码：");
String password = sc.next();
//调用Controller 层的注册方法
System.out.println(userController.registerUser(username, password));
}
//一级菜单
public void run(){
Scanner sc = new Scanner(System.in);
while(true){
mainShow();
int choose = sc.nextInt();
switch(choose){
case 1:
//登陆
login();
break;
case 2:
register();
break;
case 3:
return;
}
}
}
//二级菜单
public void run2(){
Scanner sc = new Scanner(System.in);
while(true){
IndexShow();
int choose = sc.nextInt();
switch(choose){
case 1:
add();
break;
case 2:
update();
break;
case 3:
break;
case 4:
getAll();
break;
case 5:
return;
}
}
}
//新增分类页面
public void add(){
Scanner sc = new Scanner(System.in);
System.out.println("--------------新增页面------------");
System.out.println("请输入你要新增的分类名称");
String sname = sc.next();
//调用controller新增的方法
System.out.println(sortcontroller.addSort(sname));
}
//查询所有分类页面
public void getAll(){
System.out.println("-------------查询所有分类-------------");
//调用controller的查询方法
List<Sort> list = sortcontroller.getAll();
System.out.println("分类编号\t分类名称\t");
for(Sort s:list){
System.out.println(s.getSid()+"\t"+s.getSname());
}
}
//修改分类页面
public void update(){
getAll();
System.out.println("请输入要您要修改的分类编号");
Scanner sc = new Scanner(System.in);
int id = sc.nextInt();
System.out.println("请输入你要修改的分类名称");
String sname = sc.next();
//调用Controller的修改方法
String mes = sortcontroller.updateSort(id, sname);
System.out.println(mes);
}
}
controller层：
package com.oracle.controller;
import com.oracle.domain.User;
import com.oracle.service.UserService;
public class UserController {
//封装前台数据传给后台
//接收后台数据传给后台
private UserService userService = new UserService();
public int login(String username,String password){
return userService.login(username, password);
}
public String registerUser(String username,String password){
return userService.registerUser(username, password);
}
/*public String register(String uname,String pwd){
User user = new User();
}*/
}
service层：
package com.oracle.service;
import java.sql.SQLException;
import com.oracle.dao.Userdao;
import com.oracle.domain.User;
public class UserService {
//UserService层只能调用Dao层方法（相对）
//view层调用controller层调用service层调用dao层
private Userdao userDao = new Userdao();
public int login(String username,String password){
int count = 0;
try {
count = userDao.login(username, password);
} catch (SQLException e) {
e.printStackTrace();
}
return count;
}
//注册方法
public String register(User user){
int row = 0;
String mes = "";
try {
row = userDao.register(user);
} catch (SQLException e) {
e.printStackTrace();
}
if(row > 0){
mes = "注册成功";
}else{
mes = "注册失败";
}
return mes;
}
//-----------
public String registerUser(String username,String password){
int count = 0;
String mes ="";
try {
count = userDao.registerUser(username, password);
} catch (SQLException e) {
e.printStackTrace();
}
if(count == 0){
int row = 0;
try {
row =userDao.updateUser(username, password);
} catch (SQLException e) {
e.printStackTrace();
}
if(row > 0){
mes = "注册成功！";
}else{
mes = "注册失败！";
}
}else{
mes = "用户名已存在！";
}
return mes;
}
}
dao层：
package com.oracle.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.oracle.domain.User;
import com.oracle.tools.JDBCUtils;
public class Userdao {
//登陆验证用户名或密码是否正确
public int login(String username,String password) throws SQLException{
Connection conn = JDBCUtils.get();
String sql = "select count(*) from user where uname = ? and pwd = ?";
PreparedStatement pst = conn.prepareStatement(sql);
pst.setString(1, username);
pst.setString(2, password);
ResultSet rs = pst.executeQuery();
int count = 0;
while(rs.next()){
count=rs.getInt(1);
}
return count;
}
//注册方法
//1注册用户
public int registerUser(String username,String password) throws SQLException{
Connection conn = JDBCUtils.get();
String sql = "select count(*) from user where uname = ? ";
PreparedStatement pst = conn.prepareStatement(sql);
pst.setString(1, username);
ResultSet rs = pst.executeQuery();
int count = 0;
while(rs.next()){
count=rs.getInt(1);
}
JDBCUtils.close(conn, pst, rs);
return count;
}
//2添加用户
public int updateUser(String username,String password) throws SQLException{
Connection conn = JDBCUtils.get();
String sql = "insert into user (uname,pwd) values (?,?)";
PreparedStatement pst = conn.prepareStatement(sql);
pst.setString(1, username);
pst.setString(2, password);
int row = pst.executeUpdate();
JDBCUtils.close(conn, pst);
return row;
}
public int register(User user) throws SQLException{
Connection conn = JDBCUtils.get();
String sql = "insert into user(uname,pwd) values(?,?)";
PreparedStatement pst = conn.prepareStatement(sql);
pst.setString(1, user.getUsername());
pst.setString(2, user.getPassword());
int row = pst.executeUpdate();
JDBCUtils.close(conn, pst);
return row;
}
}
domain层：
package com.oracle.domain;
public class User {
private int uid;
private String username;
private String password;
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
public String toString() {
return "User [uid=" + uid + ", username=" + username + ", password=" + password + "]";
}
public User() {
super();
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
tools层：
package com.oracle.tools;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JDBCUtils {
public static Connection get() {
//1、注册驱动
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
//2、获得连接
String url = "jdbc:mysql://localhost:3306/ceshi?characterEncoding=gbk";
String root = "root";
String pwd = "123";
Connection conn = null;
try {
conn = DriverManager.getConnection(url,root,pwd);
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
public static void close(Connection conn,PreparedStatement pst){
if(pst != null){
try {
pst.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close(Connection conn,PreparedStatement pst,ResultSet rs){
if(rs != null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(pst != null){
try {
pst.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
test层：
package com.oracle.test;
import com.oracle.view.Mainview;
public class test {
public static void main(String[] args) {
new Mainview().run();
}
}
