Here Reflection not work
package com.singleton.nonbreakable;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Constructor;
class FullySingletonClass {
public static void main(String[] args) {
SingletonImpl object1 = SingletonImpl.getInstance();
System.out.println("Object1:" + object1);
try {
FileOutputStream fos = new FileOutputStream("abc.txt");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(object1);
FileInputStream fis = new FileInputStream("abc.txt");
ObjectInputStream ois = new ObjectInputStream(fis);
SingletonImpl object2 = (SingletonImpl) ois.readObject();
System.out.println("Object2" + object2);
} catch (Exception e) {
// TODO: handle exception
}
try {
Constructor[] constructors = SingletonImpl.class.getDeclaredConstructors();
for (Constructor constructor : constructors) {
// Below code will not destroy the singleton pattern
constructor.setAccessible(true);
SingletonImpl Object3 = (SingletonImpl) constructor.newInstance();
System.out.println("Object3:" + Object3);
break;
}
} catch (Exception ew) {
}
}
}
package com.singleton.nonbreakable;
import java.io.Serializable;
class SingletonImpl implements Cloneable, Serializable {
public static SingletonImpl singleInstance = null;
private static class SingletonHolder {
public static SingletonImpl getInstance() {
if (null == singleInstance) {
singleInstance = new SingletonImpl();
}
return singleInstance;
}
}
private SingletonImpl() {
}
@Override
protected Object clone() throws CloneNotSupportedException {
return singleInstance;
};
public Object readResolve() {
System.out.println("Executing readResolve again");
return SingletonImpl.getInstance(); // FIXME
}
public static SingletonImpl getInstance() {
return SingletonHolder.getInstance();
}
}
Output :
Object1:com.singleton.nonbreakable.SingletonImpl@15db9742
Executing readResolve again
Object2com.singleton.nonbreakable.SingletonImpl@15db9742
задан Diego V 14 August 2012 в 21:41
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