As you can see from the preceding discussion, although the Singleton pattern is one of the simplest design patterns, implementing it in Java is anything but simple. The rest of this article addresses Java-speci
TheSingleton1implementation is bad because it is not thread-safe. Two different threads could both pass the if test when the mInstance is null, then both of them create instances, which violates the singleton pattern. The advantage of this implementation is the instance is created inside the In...
Joshua Bloch, Effective Java 2nd Edition p.18 中提出了使用枚举类来实现单例模式,书中指出这是最好的一种方式来实现单例。 A single-element enum type is the best way to implement a singleton /** * Enum based singleton implementation. Effective Java 2nd Edition (Joshua Bloch) p. 18 * * This...
to learn java. But for someone a bit experienced who will understand what is happening and need a bit more speed, the second implementation is definitely the way to go. Moreover, most of the time when doing multi-threading, it is a good thing to reduce the size of the synchronized code...
@implementation Singleton static Singleton *sharedSingleton = nil;<2> (Singleton *)sharedSingleton{ static dispatch_once_t once;<3> dispatch_once(&once,^{ sharedSingleton = [[self alloc] init];<4> //dosometing }); return sharedSingleton;<5> } ...
Here we will take a look at a real implementation of Singleton in Java. Java单例模式实现: public class Scoreboard { public int currentScore; //we will use this for the score later on private static Scoreboard singleton = null; //this we will need for the implementation ...
Tons of design patterns are being used by developers, and each one of them has its own utility, pros and cons in its own way, but if we talk about one design pattern that has been discussed a lot…
We must have heard multiple times that enums are always the best choice for implementingsingleton design patternin java. Are they really the best? If it is then how is it better than other available techniques? Let’s find out. Writing a singleton implementation is always tricky. I already ...
using System;using System.Threading;namespace Singleton{ // This Singleton implementation is called "double check lock". It is safe // in multithreaded environment and provides lazy initialization for the // Singleton object. class Singleton { private Singleton() { } private static Singleton _insta...
This type of implementation employs the use of enum.Enum, as written in the Java docs, provided implicit support for thread safety and only one instance is guaranteed.Java enum singletonis also a good way to have singleton with minimal effort. ...