java.io.InvalidClassException : no valid constructor

Question

当我在程序下面运行时，我收到异常

java.io.InvalidClassException: Files.SerializationMain; Files.SerializationMain; no valid constructor
    at java.io.ObjectStreamClass.checkDeserialize(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.readObject(Unknown Source)
    at Files.SerializationClass.main(SerializationClass.java:71)
Caused by: java.io.InvalidClassException: Files.SerializationMain; no valid constructor
    at java.io.ObjectStreamClass.<init>(Unknown Source)
    at java.io.ObjectStreamClass.lookup(Unknown Source)
    at java.io.ObjectOutputStream.writeObject0(Unknown Source)
    at java.io.ObjectOutputStream.writeObject(Unknown Source)
    at Files.SerializationClass.main(SerializationClass.java:61)

我在某处读到，当我们序列化任何子类时，它的基类构造函数会被触发。

class Parent123
{
    int age;
    String name;

    Parent123(int age,String name) {
        System.out.println("We are in Parent123 Constructor");
        this.age=age;
        this.name=name;
    }  
}

class SerializationMain extends Parent123 implements Serializable {
    int data1;
    String data2;

    SerializationMain(int data1,String data2)
    {
        super(20,"test");
        this.data1=data1;
        this.data2=data2;
    }

    public void setData1(int data1)
    {
        this.data1=data1;
    }
    public void setData2(String data2)
    {
        this.data2=data2;
    }
    public String getData2()
    {
        return data2;
    }
    public int getData1()
    {
        return data1;
    }
}

public class SerializationClass {

    public static void main(String args[])
    {
        System.out.println("Before Creating Object");
        SerializationMain s1=new SerializationMain(10,"Anurag");
        try
        {
            System.out.println("Serializing Object");
            FileOutputStream fis=new FileOutputStream("Test.ser");
            ObjectOutputStream ois=new ObjectOutputStream(fis);
            ois.writeObject(s1);
        } catch(Exception e1) {
            e1.printStackTrace();
        }
        try
        {
            FileInputStream fis=new FileInputStream("Test.ser");
            ObjectInputStream ois=new ObjectInputStream(fis);
            Object o1=ois.readObject();
            SerializationMain s2=(SerializationMain)o1;
        }
        catch(Exception e1)
        {
            e1.printStackTrace();
        }
    }
}//End of SerializationClass

Answer 1

将 Serializable 的实现添加到父类。