Java中transient有何作用？

transient关键字用来防止序列化域。如果一个引用类型被transient修饰，则其反序列化的结果是null。基本类型则为0。如果引用类型时不可序列化的类，则也应该使用transient修饰，它在反序列化时会被直接跳过。

可以用transient来修饰不想保存的域

下面的例子可以看到被transient修饰的name，使用序列化克隆后，反序列化的结果是null

package com.lk.B;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

public class Employee implements Cloneable,Serializable{

	private static final long serialVersionUID = 1L;

	private transient String name;

	private int age;

	public Employee(String name,int age){

		this.name = name;

		this.age = age;

	}

	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;

	}

	@Override

	public String toString() {

		// TODO Auto-generated method stub

		StringBuffer sb = new StringBuffer();

		sb.append("姓名:"+name+",");

		sb.append("年龄:"+age+"\n");

		return sb.toString();

	}

	@Override

	protected Employee clone() {

		// TODO Auto-generated method stub

		Employee employss = null;

		ByteArrayOutputStream baos = new ByteArrayOutputStream();

		try {

			ObjectOutputStream oos = new ObjectOutputStream(baos);

			oos.writeObject(this);

			oos.close();

		} catch (IOException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

		ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());

		try {

			ObjectInputStream ois = new ObjectInputStream(bais);

			employss = (Employee) ois.readObject();

			ois.close();

		} catch (IOException | ClassNotFoundException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

		return employss;

	}

}

　　

package com.lk.B;

public class Test3 {

    public static void main(String[] args) {

        Employee emp = new Employee("阿坤", 21);

        System.out.println(emp);

        Employee emp1 = emp.clone();

        System.out.println(emp1);

    }

}

姓名:阿坤,年龄:21

姓名:null,年龄:21