自我整理设计模式之单例模式（五）

一：单例模式

二：设计原则

三：实例

/**
*经典单例
*/
public class Singleton {
     
 	private static Singleton uniqueInstance;//唯一实列
	
	private Singleton() {
     };
	
	public static Singleton getInstance() {
     
	
		if(uniqueInstance == null) {
     
   			uniqueInstance = new Singleton();
  		}
  	
  		return uniqueInstance;
 	}
 }

/**
*
*多线程中的单例
*/
public class Singleton_thread {
     
 	
 	private volatile static Singleton_thread uniqueInstance;//唯一实列
	
	private Singleton_thread() {
     };
	
	public static Singleton_thread getInstance() {
     
		if(uniqueInstance == null) {
     
   			synchronized (Singleton_thread.class) {
     
    				if(uniqueInstance == null) {
     
     					uniqueInstance = new Singleton_thread();
    				}
   			}
  		}
		return uniqueInstance;
 	}
}