Java transient关键字

我们知道被transient修饰的成员变量是不能够被序列化的，但是前面加上static修饰时，序列化及反序列化是没有问题的！测试的代码Foo.java和Test.java分别如下：

import java.io.Serializable;

class Foo implements Serializable
 {
 /**
	 * 
	 */
	private static final long serialVersionUID = -253787615565537985L;
    public static int w = 1;
    public static transient int x = 2;
    public int y = 3;
    public transient int z = 4;
 }

import java.io.*;

public class Test {
    public static void main(String[] args) throws IOException {
        Foo foo = new Foo();
        System.out.printf("w: %d%n", Foo.w);
        System.out.printf("x: %d%n", Foo.x);
        System.out.printf("y: %d%n", foo.y);
        System.out.printf("z: %d%n", foo.z);
        try (FileOutputStream fos = new FileOutputStream("x.ser");
                ObjectOutputStream oos = new ObjectOutputStream(fos)) {
            oos.writeObject(foo);
        }
 
        foo = null;
 
        try (FileInputStream fis = new FileInputStream("x.ser");
                ObjectInputStream ois = new ObjectInputStream(fis)) {
            System.out.println();
            foo = (Foo) ois.readObject();
            System.out.printf("w: %d%n", Foo.w);
            System.out.printf("x: %d%n", Foo.x);
            System.out.printf("y: %d%n", foo.y);
            System.out.printf("z: %d%n", foo.z);
        } catch (ClassNotFoundException cnfe) {
            System.err.println(cnfe.getMessage());
        }
    }
}

运行结果如下所示：

w: 1
x: 2
y: 3
z: 4


w: 1
x: 2
y: 3

z: 0