transient关键字--瞬态关键字和InvalidClassException异常-原理和解决方案

transient关键字--瞬态关键字

static关键字：静态关键字

　　　　　　静态优先于非静态加载到内存中(静态优先于对象进入到内存中)

　　　　　　被static修饰的成员变量不能被序列化的，序列化的都是对象

transient关键字：瞬态关键字

　　　　　　被transient修饰成员变量，不能被序列化

 

 

static

public class Person implements Serializable {
    String name = "张三";
    static int age = 18;
    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                '}';
    }
}


public static void main(String[] args) throws IOException, ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("d:\\d.txt"));
        Object o = ois.readObject();
        ois.close();
        System.out.println(o);
    }

 

 

transient

public class Person implements Serializable {
    static String name = "张三";

    transient int age = 18;

    @Override
    public String toString() {
        return "Person{" +
                "age=" + age +
                '}';
    }
}


public static void main(String[] args) throws IOException, ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("d:\\d.txt"));
        Object o = ois.readObject();
        ois.close();
        System.out.println(o);
    }

 

InvalidClassException异常-原理和解决方案

 

    public static void main(String[] args) throws IOException, ClassNotFoundException {
        ObjectInputStream onb = new ObjectInputStream(new FileInputStream("D:\\b.txt"));
        Object o = onb.readObject();
        onb.close();

        System.out.println(o);
        Person p =(Person) o;
        System.out.println(p.getName()+p.getAge());
    }

Exception in thread"main" java.io.InvalidClassException: De_07.Person; local class incompatible: stream classdesc serialVersionUID = -647205755314169615, local class serialVersionUID = 7753234627784513054
    at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:699)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1885)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1751)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2042)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1573)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:431)
    at De_07.fanxulie.main(fanxulie.java:10)

 

 

 

 

解决方案：

private static final long serialVersionUID = 1L;

加上这句话之后无论你怎么改都不会报InvalidClassException异常的，先序列化，再反序列化