lazysingleton.java

来自「《Java与模式》一书的源代码」· Java 代码 · 共 23 行

package com.javapatterns.singleton.demos;

/**
 * Only once instance of the class may be created during the execution of any given program. Instances of this class should
 * be aquired through the getInstance() method. Notice that there are no public constructors for this class.
 */

public class LazySingleton
{
    private static LazySingleton mInstance = null;

    private LazySingleton() { }

    public static synchronized LazySingleton getInstance()
    {
        if (mInstance == null)
        {
            mInstance = new LazySingleton();
        }
        return mInstance;
    }
}