单例模式测试类
public class SingletonTest {private int value;private static SingletonTest instance;。private SingletonTest(){System.out.println("正在执行构造器。。。");}public static SingletonTest getInstance(){if(instance==null){instance=new SingletonTest();}return instance;}public int getValue() {return value;}public void setValue(int value) {this.value = value;}public static void main(String[]args){SingletonTest t1=SingletonTest.getInstance();SingletonTest t2=SingletonTest.getInstance();t2.setValue(1);System.out.println(t1==t2);}}