an introduction
1. If the parent class implements the serialization interface, the subclass does not need to implement the serialization interface.
2. When the object is created, the constructor of the parent class is called recursively.
3.
When deserializing a subclass object,
if its parent class does not implement the serialization interface,
the constructor of its parent class will be called, otherwise it will not be called.
Two examples
package
com.imooc.io;
import
java.io.FileInputStream;
import
java.io.FileOutputStream;
import
java.io.ObjectInputStream;
import
java.io.ObjectOutputStream;
import
java.io.Serializable;
public
class
ObjectSeriaDemo2 {
public
static
void
main(String[] args)
throws
Exception{
ObjectOutputStream east =
new
ObjectOutputStream (
new
FileOutputStream(
"demo/obj1.dat"
));
Foo2 foo1 =
new
Foo2();
//When creating an object, the constructor of the parent class is called recursively
oos.writeObject (foo1);
oos.flush ();
oos.close();
//Whether deserialization recursively calls the constructor of the parent class, it cannot be proved
ObjectInputStream ois =
new
ObjectInputStream(
new
FileInputStream(
"demo/obj1.dat"
));
Foo2 foo2 = (Foo2)ois.readObject();
System.
out
.println(foo2);
ois.close();
ObjectOutputStream oos1 =
new
ObjectOutputStream(
new
FileOutputStream(
"demo/obj1.dat"
));
Bar2 bar1 =
new
Bar2();
oos1.writeObject(bar1);
oos1.flush();
oos1.close();
ObjectInputStream ois1 =
new
ObjectInputStream(
new
FileInputStream(
"demo/obj1.dat"
));
Bar2 bar2 = (Bar2)ois1.readObject();
System.
out
.println(bar2);
ois1.close();
/*
* 对子类对象进行反序列化操作时，
* 如果其父类没有实现序列化接口
* 那么其父类的构造函数会被调用
*/
}
}
/*
* 一个类实现了序列化接口，那么其子类都可以进行序列化
*/
class
Foo
implements
Serializable{
public
Foo(){
System.
out
.println(
"foo..."
);
}
}
class
Foo1
extends
Foo{
public
Foo1(){
System.
out
.println(
"foo1..."
);
}
}
class
Foo2
extends
Foo1{
public
Foo2(){
System.
out
.println(
"foo2..."
);
}
}
class
Bar{
public
Bar(){
System.
out
.println(
"bar"
);
}
}
class
Bar1
extends
Bar{
public
Bar1(){
System.
out
.println(
"bar1.."
);
}
}
class
Bar2
extends
Bar1
implements
Serializable{
public
Bar2(){
System.
out
.println(
"bar2..."
);
}
}
三 运行结果
foo...
foo1...
foo2...
com.imooc.io.Foo2@913fe2
bar
bar1..
bar2...
bar
bar1..
com.imooc.io.Bar2@eb7859