2018-11-30[Gerald Wang] Singleton

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package org.demo;

import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.lang.reflect.Constructor;

public enum Singleton {

INSTANCE;

private String name;
private Singleton() {
}

public String getName() {
    return this.name;
}

public void setName(String name) {
    this.name = name;
}

public static void main(String[] args) {
    try {
        Class s = Class.forName("org.demo.Singleton");
        Constructor ct = s.getDeclaredConstructor();
        ct.setAccessible(true);
        System.out.println(ct.newInstance());
    } catch (Exception e) {
        e.printStackTrace();
    }

    try {
        Singleton instance = Singleton.INSTANCE;

        ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("Singleton.INSTANCE"));
        objectOutputStream.writeObject(instance);
        objectOutputStream.close();

        ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream("Singleton.INSTANCE"));

        Singleton instance2 = (Singleton)objectInputStream.readObject();
        System.out.println(instance == instance2);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

}