对象序列化

将对象得状态存储到特定存储介质中的过程叫对象的序列化
1. 支持可序列化实现接口Java.io.serializable接口
2. 对象序列化的步骤
- 创建一个对象输出流-objectoutputstream
- readobject读取流中的类容
1. 购物：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class SerGood {

    public static void main(String[] args) {
        // 组方法
        int i=0;
        SerGood sg=new SerGood();
        sg.createDepositFile();
        ArrayList<Good> goodList=new ArrayList<Good>();
        System.out.println("开始购物：");
        Scanner scanner=new Scanner(System.in);
        do {
            System.out.println("请通过输入商品名来选择你需要的东西：");
            String good_Name=scanner.next();
            Random random=new Random();
            double price=random.nextDouble()*90+10;
            String number=String.valueOf(random.nextInt(10));
            Good good=new Good(number,good_Name,price);
            if(sg.checkOrder(good)) {
                i=1;
                goodList.add(good);
            }else {
                System.out.println("你已经买过这件商品！");
            }
            sg.createOrderFile(goodList);
            System.out.println("是否继续购物y/n");
            if(scanner.next().equals("n")) {

                break;
            }
        }while(true);

            sg.showOrder();


        System.out.println("欢迎再次光临！");
    }
    ArrayList<Good> list;
    public void createDepositFile(){
        File file=new File("E:/javaworkspace/old/save.txt");
        if(!file.exists()) {
            try {
                ObjectOutputStream oos=new ObjectOutputStream(
                        new FileOutputStream("E:/javaworkspace/old/save.txt"));
                oos.writeObject(" ");
                oos.flush();
                oos.close();
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }else {
            System.out.println("有此文件");
        }
    }
    public void createOrderFile(ArrayList<Good> list) {
        try {
            ObjectOutputStream oos=new ObjectOutputStream(
                    new FileOutputStream("E:/javaworkspace/old/save.txt"));
            oos.writeObject(list);
            oos.flush();
            oos.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public Object readOrder() {
        try {
            ObjectInputStream ois=new ObjectInputStream(
                    new FileInputStream("E:/javaworkspace/old/save.txt"));

            Object obj=ois.readObject();
            ois.close();
            if(obj!=null) {
                return obj;
                }else {
                    return null;
                }


        } 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();
        }
        return null;

    }
    public boolean checkOrder(Good good) {
        boolean bool=true;
        SerGood sg=new SerGood();
        Object obj=sg.readOrder();
        if(obj!=null) {
            @SuppressWarnings("unchecked")
            ArrayList<Good> list=(ArrayList<Good>) obj;
            for (Good good2 : list) {
                if(good2.getGood_Name().equals(good.getGood_Name())) {

                    bool=false;
                }
            }
        }

        return bool;

    }
    public void showOrder() {
        double price=0;
        SerGood sg=new SerGood();
        Object obj=sg.readOrder();
        if(obj!=null) {
            @SuppressWarnings("unchecked")
            ArrayList<Good> list=(ArrayList<Good>) obj;
            for (Good good2 : list) {

                    System.out.println("你的购物单信息如下：\n商品编号——"+good2.getGood_Number()
                    +"\t商品名称——"+good2.getGood_Name()+"\t商品价格——"+good2.getGood_Price());
                    price+= good2.getGood_Price();


            }
        }

        System.out.println("商品的总价格为："+price);

    }


}