用java完成一个电商系统的商品模块功能

项目：完成一个电商系统的商品模块功能，商品类包含以下属性：商品ID, 商品名，类别名，单价，库存量，产地，计量单位等信息，要求实现商品管理功能以及管理员功能，具体如下：

1.管路员登录（账号密码固定admin/admin）

2.修改管理员密码

3.商品添加

4.商品列表

5.查询指定id商品

6.根据商品id删除商品

7.根据id修改商品价格

8.根据id修改指定商品库存

9.根据商品类别查询所有商品

10.查询指定价格区间的商品信息

根据项目要求，我们首先分析题目，知道此项目至少四个类：管理员类、商品类、系统类、测试类。

由于我们决定对此系统进行优化，要求能够对数据进行保存，所以我们用流的相关知识，将数据写入已经创建好的文档中，使其自动读写，以便管理，三个文档分别用于保存商品信息、id、user。

首先是user类，

package com01;

import java.io.Serializable;

@SuppressWarnings("serial")
public class User implements Serializable{
	private String userName;
	private String password;

	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;
	}

	@Override
	public String toString() {
		return "User [userName=" + userName + ", password=" + password + "]";
	}

}

然后是Goods类

package com01;

import java.io.Serializable;

@SuppressWarnings("serial")
public class Goods implements Serializable {
	private int id;
	private String name;
	private String typeName;
	private double price;
	private int count;
	// 产地
	private String placeOrigin;
	// 单位
	private String units;
	

	public Goods() {
		
	}

	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 getTypeName() {
		return typeName;
	}

	public void setTypeName(String typeName) {
		this.typeName = typeName;
	}

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	public int getCount() {
		return count;
	}

	public void setCount(int count) {
		this.count = count;
	}

	public String getPlaceOrigin() {
		return placeOrigin;
	}

	public void setPlaceOrigin(String placeOrigin) {
		this.placeOrigin = placeOrigin;
	}

	public String getUnits() {
		return units;
	}

	public void setUnits(String units) {
		this.units = units;
	}

	@Override
	public String toString() {
		return "Goods [id=" + id + ", name=" + name + ", typeName=" + typeName + ", price=" + price + ", count=" + count
				+ ", placeOrigin=" + placeOrigin + ", units=" + units + "]";
	}

}

GoodsSystem类：

package com01;

import java.io.BufferedReader;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Scanner;

public class GoodsSystem {
	private User user;
	private Scanner scanner;
	private ArrayList<Goods> goodss;
	private int maxId;

	public GoodsSystem() {
		// TODO Auto-generated constructor stub
		getSystemUser();
		readMaxId();
		readGoodss();
		this.scanner = new Scanner(System.in);
	}

	// 登录
	public void login() {
		// TODO Auto-generated method stub
		String userName;
		String password;
		System.out.println("欢迎来到德莱Store！");
		System.out.print("请输入用户名：");
		userName = scanner.nextLine();
		System.out.print("请输入密码：");
		password = scanner.nextLine();
		if (user.getUserName().equals(userName) && user.getPassword().equals(password)) {
			System.out.println("登录成功！！！");
			menuFromSelect();
		} else {
			System.out.println("用户名和密码不匹配，请重新输入！");
			login();
		}
	}

	// 得到账户中的信息
	public void getSystemUser() {
		// TODO Auto-generated method stub
		File file = new File("E:\\软帝培训\\user.txt");
		FileInputStream fis = null;
		ObjectInputStream ois = null;
		try {
			fis = new FileInputStream(file);
			ois = new ObjectInputStream(fis);
			Object obj = ois.readObject();
			if (obj instanceof User) {
				this.user = (User) obj;
			}
		} catch (EOFException e) {
			this.user = new User();
			user.setUserName("admin");
			user.setPassword("admin");
			writeUserToLocal();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (ois != null) {
				try {
					ois.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (fis != null) {
				try {
					fis.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	// 把内存中的用户信息写入本地
	public void writeUserToLocal() {
		// TODO Auto-generated method stub
		FileOutputStream fos = null;
		ObjectOutputStream oos = null;
		try {
			fos = new FileOutputStream("E:\\软帝培训\\user.txt");
			oos = new ObjectOutputStream(fos);
			oos.writeObject(user);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (fos != null) {
				try {
					fos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (oos != null) {
				try {
					oos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	// 打印菜单
	public String printMenu() {
		// TODO Auto-generated method stub
		System.out.println("\t");
		System.out.println("\t欢迎来到商城管理员界面");
		System.out.println("---------------------------");
		System.out.println("1.商品列表");
		System.out.println("2.商品添加");
		System.out.println("3.根据id查询指定商品");
		System.out.println("4.根据商品类别查询所有商品");
		System.out.println("5.查询指定价格区间的商品信息");
		System.out.println("6.根据id删除商品根据");
		System.out.println("7.根据id指定商品价格");
		System.out.println("8.根据id修改商品库存");
		System.out.println("9.修改密码");
		System.out.println("10.退出系统");
		System.out.println(">");
		return scanner.nextLine();
	}

	// 菜单查询界面
	public void menuFromSelect() {
		// TODO Auto-generated method stub
		String result = printMenu();
		switch (result) {
		case "1":
			goodsList();
			menuFromSelect();
			break;
		case "2":
			addGoods();
			menuFromSelect();
			break;
		case "3":
			findListById();
			menuFromSelect();
			break;
		case "4":
			findListBytypeName();
			menuFromSelect();
			break;
		case "5":
			findListByPrice();
			menuFromSelect();
			break;
		case "6":
			deleteGoods();
			menuFromSelect();
			break;
		case "7":
			setPrice();
			menuFromSelect();
			break;
		case "8":
			reCountById();
			menuFromSelect();
			break;
		case "9":
			rePsw();
			menuFromSelect();
			break;
		case "10":
			break;
		}
	}

	// 读取本地ID
	public void readMaxId() {
		// TODO Auto-generated method stub
		FileReader fr = null;
		BufferedReader br = null;
		try {
			fr = new FileReader("E:\\软帝培训\\id.txt");
			br = new BufferedReader(fr);
			this.maxId = Integer.parseInt(br.readLine());
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (NumberFormatException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (br != null) {
				try {
					br.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (fr != null) {
				try {
					fr.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	// 把最大id写入本地
	public void writeMaxId() {
		FileWriter fw = null;
		try {
			fw = new FileWriter("E:\\软帝培训\\id.txt");
			fw.write(this.maxId + "");
//			fw.write(this.maxId);
			fw.flush();// 刷新
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (NumberFormatException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (fw != null) {
				try {
					fw.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	// 添加商品
	public void addGoods() {
		// TODO Auto-generated method stub
		Goods goods = new Goods();
		goods.setId(maxId + 1);
		System.out.print("请输入商品名称：");
		goods.setName(scanner.nextLine());
		System.out.print("请输入商品分类：");
		goods.setTypeName(scanner.nextLine());
		System.out.print("请输入商品价格：");
		goods.setPrice(Double.parseDouble(scanner.nextLine()));
		System.out.print("请输入商品库存：");
		goods.setCount(Integer.parseInt(scanner.nextLine()));
		System.out.print("请输入商品产地：");
		goods.setPlaceOrigin(scanner.nextLine());
		System.out.print("请输入商品计量单位：");
		goods.setUnits(scanner.nextLine());
		goodss.add(goods);
		writeGoodssToLocal();
		maxId++;
		writeMaxId();
		System.out.println("商品添加成功！！！");
	}

	// 读取商品信息
	public void readGoodss() {
		// TODO Auto-generated method stub
		File file = new File("E:\\软帝培训\\goodss.txt");
		FileInputStream fis = null;
		ObjectInputStream ois = null;
		try {
			fis = new FileInputStream(file);
			ois = new ObjectInputStream(fis);
			Object obj = ois.readObject();
			if (obj instanceof ArrayList) {
				this.goodss = (ArrayList<Goods>) obj;
			}
		} catch (EOFException e) {
			// 读取失败，第一次创建，所以需要创建一个默认账户
			this.goodss = new ArrayList<Goods>();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (ois != null) {
				try {
					ois.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (fis != null) {
				try {
					fis.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	// 将商品信息写入本地
	public void writeGoodssToLocal() {
		// TODO Auto-generated method stub
		FileOutputStream fos = null;
		ObjectOutputStream oos = null;
		try {
			fos = new FileOutputStream("E:\\软帝培训\\goodss.txt");
			oos = new ObjectOutputStream(fos);
			oos.writeObject(goodss);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (oos != null) {
				try {
					oos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (fos != null) {
				try {
					fos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	// 根据价格查询商品信息
	public void findListByPrice() {
		System.out.println("请输入最低价格：");
		double minPrice = Double.parseDouble(scanner.nextLine());
		System.out.println("请输入最高价格：");
		double maxPrice = Double.parseDouble(scanner.nextLine());
		boolean b = false;
		for (Goods goods : goodss) {
			if (goods.getPrice() > minPrice && goods.getPrice() < maxPrice) {
				b = true;
				System.out.println(goods);
			}
		}
		if (!b) {
			System.out.println("没有在此区间的商品！");
		}
	}

	// 根据id寻找商品信息
	private int findListById() {
		System.out.print("请输入您要查询的ID:");
		int id = Integer.parseInt(scanner.nextLine());
		int index = findListById(id);
		if (index != -1) {
			System.out.println(goodss.get(index));
		} else {
			System.out.println("没有查询到id为：" + id + "的商品");
		}
		return index;
	}

	private int findListById(int id) {
		int index = Utils.halfQuery(goodss, id, new HalfQueryInter<Goods>() {
			@Override
			public double getNumber(Goods g) {
				// TODO Auto-generated method stub
				return g.getId();
			}
		});
		return index;
	}

	// 根据类别寻找商品信息
	public void findListBytypeName() {
		// TODO Auto-generated method stub
		boolean b = false;
		System.out.println("请输入你要寻找的类别：");
		String type = scanner.nextLine();
		for (Goods goods : goodss) {
			if (goods.getTypeName().equals(type)) {
				System.out.println(goods);
				b = true;
			}
		}
		if (!b) {
			System.out.println("查无此商品！");
		}
	}

	// 根据id修改库存
	public void reCountById() {
		// TODO Auto-generated method stub
		System.out.println("请输入你要查找的商品id:");
		int id = Integer.parseInt(scanner.nextLine());
		int index = findListById(id);
		if (index == -1) {
			System.out.println("没有你要找的商品！");
		} else {
			System.out.println("请输入你要修改的库存：");
			int count = Integer.parseInt(scanner.nextLine());
			goodss.get(index).setCount(count);
			System.out.println("修改成功！");
			writeGoodssToLocal();
		}
	}

	// 根据id修改商品价格
	public void setPrice() {
		// TODO Auto-generated method stub
		System.out.print("请输入你要查找的商品id");
		int id = Integer.parseInt(scanner.nextLine());
		int index = findListById(id);
		if (index == -1) {
			System.out.println("查无此商品");
		} else {
			System.out.println("请输入你要修改的价格：");
			double price = Double.parseDouble(scanner.nextLine());
			goodss.get(index).setPrice(price);
			writeGoodssToLocal();
			System.out.println("价格修改成功！");
		}
	}

	// 删除商品
	public void deleteGoods() {
		// TODO Auto-generated method stub
		System.out.println("请输入你要删除的商品id:");
		int id = Integer.parseInt(scanner.nextLine());
		int index = findListById(id);
		if (index == -1) {
			System.out.println("没有你找的商品！");
		} else {
			goodss.remove(index);
			System.out.println("删除成功！");
			writeGoodssToLocal();
			for (Goods goods : goodss) {
				System.out.println(goods);
			}
		}
	}

	// 修改密码
	public void rePsw() {
		// TODO Auto-generated method stub
		String lastPsw;
		String newPsw1;
		String newPsw2;
		System.out.print("请输入原始密码：");
		lastPsw = scanner.nextLine();
		if (!this.user.getPassword().equals(lastPsw)) {
			System.out.println("密码错误请重新输入！");
			return;
		}
		System.out.print("请输入新密码：");
		newPsw1 = scanner.nextLine();
		System.out.print("请再次输入新密码：");
		newPsw2 = scanner.nextLine();
		if (newPsw1.equals(newPsw2)) {
			this.user.setPassword(newPsw2);
			writeUserToLocal();
			System.out.println("修改成功！！！");
		} else {
			System.out.println("两次密码输入不一致，修改失败！！！");
			return;
		}
	}

	// 商品列表
	public void goodsList() {
		// TODO Auto-generated method stub
		if (goodss.size() == 0) {
			System.out.println("没有任何商品！");
			return;
		}
		for (Goods goods : goodss) {
			System.out.println(goods);
		}
	}
}

因为我们需要查找id这个功能能运用到折半查询，所以我们创建了一个工具类和一个接口，将折半查询封装起来以便调用。

工具 Utils类：

package com01;

import java.util.List;

public class Utils {
	public static int query(int[] buf, int n) {
		// TODO Auto-generated method stub
		for (int i = 0; i < buf.length; i++) {
			if (buf[i] == 0) {
				return i;
			}
		}
		return -1;
	}
	
	public static <T> int halfQuery(List<T> buf, int n,HalfQueryInter<T> h) {
		return halfQuerySys(buf,n,0, buf.size(),h);
	}

	private static <T> int halfQuerySys(List<T> buf, int n, int sta, int end, HalfQueryInter<T> h) {
		// TODO Auto-generated method stub
		if (sta > end) {
			return -1;
		}
		int half = (sta + end) / 2;
		if(h.getNumber(buf.get(half)) == n) {
			return half;
		}else if(h.getNumber(buf.get(half)) > n) {
			return halfQuerySys(buf,n,sta,half-1,h);
		}else {
			return halfQuerySys(buf,n,half+1,end,h);
		}
	}
}

接口HalfQueryInter

package com01;

public interface HalfQueryInter<T> {
	public double getNumber(T t);
}

最后测试类：

package com01;

public class Test {
	public static void main(String[] args) {
		GoodsSystem gs = new GoodsSystem();
		gs.login();
	}
}