序列化

原生序列化：

https://blog.csdn.net/jtf8525140/article/details/81094222

MessagePack

Protocol Buffers

Dubbo kryo

序列化可以系统的通用性、强壮性、优化性能，同时让系统更易于调试和扩展

1.序列化不保存静态变量的状态

2. transient 修饰的参数 不参与序列化

3.父类对象属性进行序列化的时候，要实现Serializable 接口

 Peron

public class Person implements Serializable{


    private static final long serialVersionUID = -2140242550063332020L;

    // transient 修饰的参数 不参与序列化
    private transient int age;

    private  String name;

    public static int gender = 1;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

序列化对象

public class SerializeDemo {
    public static void main(String[] args) {
        serializePerson();
        //序列化不保存静态变量的状态
        Person.gender = 2;
        deSerializePerson();
    }


    private static void serializePerson() {
        try {
            ObjectOutputStream oo = new ObjectOutputStream(new FileOutputStream(new File("person")));
            Person person = new Person();
            person.setAge(18);
            person.setName("mic");
            oo.writeObject(person);
            oo.flush();
            oo.writeObject(person);
            oo.flush();
            System.out.println("序列化成功"+new File("person").length());
            //-----------------------
            // 重复保存对象的时候，保存的是对象的引用
            ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(new File("person")));
            Person person1 = (Person) inputStream.readObject();
            Person person2 = (Person) inputStream.readObject();
            System.out.println(person1==person2);
            //---------------------------
            oo.close();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }


    private static void deSerializePerson() {
        try {
            ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(new File("person")));
            Object o = inputStream.readObject();
            if (o instanceof Person) {
                Person person = (Person) o;
                System.out.println(person.getAge()+","+ person.gender);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

 子类对象继承父类对象属性序列化的时候，需要父类也要实现序列化

/**
 * 父类对象属性进行序列化的时候，要实现Serializable 接口
 */
public class SuperPerson implements Serializable{

    private int age;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

User

public class User extends SuperPerson implements Serializable{


    private static final long serialVersionUID = 1362833492159178974L;

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

 demo:

public class SuperPersonDemo {

    public static void main(String[] args) {
        serializePerson();
        //序列化不保存静态变量的状态
        Person.gender = 2;
        deSerializePerson();
    }


    private static void serializePerson() {
        try {
            ObjectOutputStream oo = new ObjectOutputStream(new FileOutputStream(new File("person")));
            User person = new User();
            person.setAge(18);
            person.setName("mic");
            oo.writeObject(person);
            System.out.println("序列化成功");
            oo.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    private static void deSerializePerson() {
        try {
            ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream(new File("person")));
            Object o = inputStream.readObject();
            if (o instanceof User) {
                User person = (User) o;
                System.out.println(person.getAge()+","+person.getName());
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}