Java——对象数组和对象流

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.util.Arrays;

class Student implements Serializable
{
    /**
     * 序列化的类
     */
    private static final long serialVersionUID = 1L;
    public String name;
    public int age;
    public String IdCard;
    public Student(String name, int age, String idCard) {
        super();
        this.name = name;
        this.age = age;
        IdCard = idCard;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getIdCard() {
        return IdCard;
    }
    public void setIdCard(String idCard) {
        IdCard = idCard;
    }
    @Override
    public String toString() {
        return "Student [name=" + name + ", age=" + age + ", IdCard=" + IdCard + "]";
    }
    public Student() {}
}


public class OneTime {
         //写对象
    private static void writeObject()
      {   //序列化的类，实例化对象数组
          Student[] st = {new Student("wei",19,"1803050208"),
                  new Student("zhong",20,"1803050209"),
                  new Student("wang",21,"1803050211"),
                  new Student("li",18,"1803050210")};
          File f = new File("C:\\Users\\Easyboyxxx\\st.obj");
               //对象流
          try {
            OutputStream out = new FileOutputStream(f);
            ObjectOutputStream ob = new ObjectOutputStream(out);
            ob.writeObject(st);
            ob.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
      }
    private static void readObject()
    {
        File f = new File("C:\\Users\\Easyboyxxx\\st.obj");
        try {
            InputStream in = new FileInputStream(f);
            ObjectInputStream ob = new ObjectInputStream(in);
            Student[] st = (Student[])ob.readObject();  //注意读出的是对象数组，不是单个对象
            ob.close();
            System.out.println(Arrays.toString(st));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        
    }

   //主方法调用读写方法。
  public static void main(String args[])
  {
      writeObject();
      readObject();
      
  }
  
}