package com.csdn.fruit.view;
import com.csdn.fruit.pojo.Fruit;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.function.Consumer;
import java.util.function.Predicate;
public class Menu {
Scanner input = new Scanner(System.in);
List<Fruit> fruitList = new ArrayList<>();
{
try {
loadData();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
//加载数据
public void loadData() throws IOException {
InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("fruit.dat");
if (inputStream != null) {
//字节流转换成字符流
//字节流：InputStream 字符流：Reader 字符转换流：InputStreamReader
BufferedReader bf = new BufferedReader(new InputStreamReader(inputStream));
String str = null;
while ((str = bf.readLine()) != null) {
String[] arr = str.split(" ");
String fname = arr[0];
Integer price = Integer.parseInt(arr[1]);
Integer fcount = Integer.parseInt(arr[2]);
String remark = arr[3];
Fruit fruit = new Fruit(fname, price, fcount, remark);
fruitList.add(fruit);
}
}
}
//显示主菜单
public int showMainMenu() {
System.out.println("================欢迎使用水果库存系统===================");
System.out.println("1.显示库存列表");
System.out.println("2.添加库存记录");
System.out.println("3.查看特定库存");
System.out.println("4.水果下架");
System.out.println("5.退出");
System.out.println("====================================================");
System.out.print("请选择：");
return input.nextInt();
}
//显示库存列表
public void showFruitList() {
System.out.println("----------------------------------------------------");
System.out.println("名称\t\t单价\t\t库存\t\t备注");
if (fruitList == null || fruitList.size() <= 0) {
System.out.println("对不起，库存为空！");
} else {
/*fruitList.forEach(new Consumer<Fruit>() {
@Override
public void accept(Fruit fruit) {
System.out.println(fruit);
}
});*/
// fruitList.forEach(fruit -> System.out.println(fruit));
fruitList.forEach(System.out::println);
}
System.out.println("----------------------------------------------------");
}
//根据名称查询指定的库存记录
public Fruit getFruitByFname(String fname) {
//判断型接口 有参数，返回值是布尔类型
/* fruitList.stream().filter(new Predicate<Fruit>() {
@Override
public boolean test(Fruit fruit) {
return fname.equals(fruit.getFname());
}
});*/
return fruitList.stream().filter(fruit -> fname.equals(fruit.getFname())).findFirst().orElseGet(() -> null);
/* for (Fruit fruit : fruitList) {
if (fname.equals(fruit.getFname())) {
return fruit;
}
}
return null;*/
}
//添加库存记录
public void addFruit() {
System.out.print("请输入水果名称：");
String fname = input.next();
Fruit fruit = getFruitByFname(fname);
if (fruit == null) {
System.out.print("请输入水果单价：");
Integer price = input.nextInt();
System.out.print("请输入水果库存：");
Integer fcount = input.nextInt();
System.out.print("请输入水果备注：");
String remark = input.next();
fruit = new Fruit(fname, price, fcount, remark);
fruitList.add(fruit);
} else {
System.out.print("请输入追加的库存量：");
Integer fcount = input.nextInt();
fruit.setFcount(fruit.getFcount() + fcount);
}
System.out.println("添加成功！");
}
//查看特定库存记录
public void showFruitInfo() {
System.out.print("请输入水果名称：");
String fname = input.next();
Fruit fruit = getFruitByFname(fname);
if (fruit == null) {
System.out.println("对不起，没有找到对应的库存记录！");
} else {
System.out.println("----------------------------------------------------");
System.out.println("名称\t\t单价\t\t库存\t\t备注");
System.out.println(fruit);
System.out.println("----------------------------------------------------");
}
}
//水果下架
public void delFruit() {
System.out.print("请输入水果名称：");
String fname = input.next();
Fruit fruit = getFruitByFname(fname);
if (fruit == null) {
System.out.println("对不起，没有找到需要下架的库存记录！");
} else {
System.out.print("是否确认下架?（Y/N）");
String confirm = input.next();
if ("y".equalsIgnoreCase(confirm)) {
fruitList.remove(fruit);
}
}
}
//退出
public boolean exit() {
System.out.print("是否确认退出？（Y/N）");
String confirm = input.next();
boolean flag= !"y".equalsIgnoreCase(confirm);
if (!flag) {
try {
saveData();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
return flag;
}
//保持数据
public void saveData() throws IOException {
PrintWriter pw = new PrintWriter(new FileWriter("pro02-fruit-IO/src/main/resources/fruit.dat"));
/* fruitList.forEach(new Consumer<Fruit>() {
@Override
public void accept(Fruit fruit) {
pw.println(fruit.getFname() + " " + fruit.getPrice() + " " + fruit.getFcount() + " " + fruit.getRemark());
}
});*/
fruitList.forEach(fruit -> pw.println(fruit.getFname() + " " + fruit.getPrice() + " " + fruit.getFcount() + " " + fruit.getRemark()));
pw.flush();
}
}
java复制代码
package com.csdn.fruit.view;
public class Client {
public static void main(String[] args) {
Menu m = new Menu();
boolean flag = true;
while (flag) {
int slt = m.showMainMenu();
switch (slt) {
case 1:
m.showFruitList();
break;
case 2:
m.addFruit();
break;
case 3:
m.showFruitInfo();
break;
case 4:
m.delFruit();
break;
case 5:
//方法设计时是否需要返回值，依据是：是否在调用的地方需要留下一些值用于再运算
flag = m.exit();
break;
default:
System.out.println("你不按套路出牌！");
break;
}
}
System.out.println("谢谢使用！再见！");
}
}
