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