java項目分包

項目分層（分包）

view層：視圖層，項目中的界面；
controller層：控制層，獲取界面上的數據；將要實現的功能交給業務層處理；
service層作用: 業務層, 功能的實現, 與controller控制層和數據訪問層DAO交互, 將對數據庫的操作交給DAO數據訪問層來處理
dao層作用: 數據訪問層, 用來操作數據庫表的數據
db數據庫: 這里指MySQL
domain 實體包: 存放JavaBean
tools工具包:存放項目中使用到的工具類
test測試包: 存放項目功能測試的代碼

 各舉一個例子：

view層：

 

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("--------歡迎進入商城--------");
            System.out.println("1、登陸");
            System.out.println("2、注冊");
            System.out.println("3、退出");
            System.out.println("請輸入你的選擇");        
        }
        public void IndexShow(){
            System.out.println("-------------首頁-------------");
            System.out.println("1、新增分類");
            System.out.println("2、修改分類");
            System.out.println("3、刪除分類");
            System.out.println("4、查詢所有分類");
            System.out.println("5、返回上級菜單");
            System.out.println("請輸入你的選擇");    
        }
        //登錄頁面
        public void login(){
            System.out.println("-----------登陸頁面-------------");
            System.out.println("請輸入用戶名：");
            Scanner  sc = new Scanner(System.in);
            String username = sc.next();
            System.out.println("請輸入密碼：");
            String password = sc.next();
            //調用Controller 層的登陸方法
            int count =  userController.login(username, password);
            if(count > 0){
                System.out.println("登陸成功！！");
                run2();
            }else{
                System.out.println("登陸失敗");
            }
        }
        //注冊頁面
        public void register(){
            System.out.println("-----------注冊頁面-------------");
            System.out.println("請輸入用戶名：");
            Scanner  sc = new Scanner(System.in);
            String username = sc.next();
            System.out.println("請輸入密碼：");
            String password = sc.next();
            //調用Controller 層的注冊方法
            System.out.println(userController.registerUser(username, password));
        }
        //一級菜單
        public void run(){
            Scanner sc = new Scanner(System.in);
            while(true){
                mainShow();
                int  choose = sc.nextInt();
                switch(choose){
                case 1:
                    //登陸
                    login();
                    break;
                case 2:
                    register();
                    break;
                case 3:
                    return;
                }
            }
        }
        //二級菜單
        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;
                }
            }
        }
        //新增分類頁面
        public  void  add(){
            Scanner sc = new Scanner(System.in);
            System.out.println("--------------新增頁面------------");
            System.out.println("請輸入你要新增的分類名稱");
            String  sname = sc.next();
            //調用controller新增的方法
            System.out.println(sortcontroller.addSort(sname));
        }
        //查詢所有分類頁面
        public void getAll(){
            System.out.println("-------------查詢所有分類-------------");
            //調用controller的查詢方法
            List<Sort> list = sortcontroller.getAll();
            System.out.println("分類編號\t分類名稱\t");
            for(Sort s:list){
                System.out.println(s.getSid()+"\t"+s.getSname());
            }
        }
        //修改分類頁面
        public void update(){
            getAll();
            System.out.println("請輸入要您要修改的分類編號");
            Scanner sc = new  Scanner(System.in);
            int  id = sc.nextInt();
            System.out.println("請輸入你要修改的分類名稱");
            String  sname = sc.next();
            //調用Controller的修改方法
            String mes = sortcontroller.updateSort(id, sname);
            System.out.println(mes);
        }
}

 

controller層：

package com.oracle.controller;

import com.oracle.domain.User;
import com.oracle.service.UserService;

public class UserController {
    //封裝前台數據傳給后台
    //接收后台數據傳給后台
            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層：

 

package com.oracle.service;

import java.sql.SQLException;

import com.oracle.dao.Userdao;
import com.oracle.domain.User;

public class UserService {
        //UserService層只能調用Dao層方法（相對）
        //view層調用controller層調用service層調用dao層
       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;
       }
       //注冊方法
       public String register(User user){
           int row = 0;
           String mes = "";
           try {
            row = userDao.register(user);
        } catch (SQLException e) {
            e.printStackTrace();
        }
           if(row > 0){
               mes = "注冊成功";
           }else{
               mes = "注冊失敗";
           }
           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 = "注冊成功！";
                 }else{
                     mes = "注冊失敗！";
                 }
             }else{
                 mes = "用戶名已存在！";
             }
             return mes;
       }
}

dao層：

 

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 {
        //登陸驗證用戶名或密碼是否正確
       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;
       }
       //注冊方法
       //1注冊用戶
       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添加用戶
       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層：

 

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層：

 

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、注冊驅動
                try {
                    Class.forName("com.mysql.jdbc.Driver");
                } catch (ClassNotFoundException e) {
                    e.printStackTrace();
                }
                //2、獲得連接
                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層：

package com.oracle.test;

import com.oracle.view.Mainview;

public class test {

    public static void main(String[] args) {
        new Mainview().run();
    }
}