Singleton for multithreading in Java
October 26, 2014
1 min read
Everyone knows what is singleton pattern, but how to implement a singleton class in multithreaded environment? Next, I’m going to present best approaches for this use case.
Bill Pugh Singleton Implementation
public class Singleton {
private Singleton() { }
private static class SingletonHolder {
private static final Singleton INSTANCE = new Singleton();
}
public static Singleton getInstance() {
return SingletonHolder.INSTANCE;
}
}
Thread Safe Double Checked Singleton Implementation
public class Singleton {
private static Singleton instance;
private Singleton() { }
public static Singleton getInstance() {
if(instance == null) {
synchronize (Singleton.class) {
if(instance == null) {
instance = new Singleton();
}
}
}
return instance;
}
}
