- 懒汉模式的优化（synchronize解决线程安全问题）
package design_mode;
public class SingletonSynchronized {
private static SingletonSynchronized singletonSynchronized = null;
private SingletonSynchronized(){
System.out.println("线程安全的单例模式");
}
public static SingletonSynchronized getSingletonSynchronized(){
synchronized (SingletonSynchronized.class){
if ((singletonSynchronized == null)){
singletonSynchronized = new SingletonSynchronized();
}
return singletonSynchronized;
}
}
}
- 双重锁认证进一步提高性能
package design_mode;
public class SingletonHight {
private static SingletonHight singletonHight = null;
private SingletonHight(){
System.out.println("最终版单例模式");
}
public static SingletonHight getSingletonHight(){
if(singletonHight==null){
synchronized (SingletonHight.class){
if(singletonHight==null){
singletonHight = new SingletonHight();
}
}
}
return singletonHight;
}
}
- 通过静态内部类实现单例模式的延迟加载和线程安全
这种方式是通过静态内部类实现的，静态内部类只有在调用时才会加载，这样就保证了延迟初始化，但是遇到序列化对象时会失效。
public class SingletonInnerObject {
private SingletonInnerObject(){};
private static class InnerObject {
private static SingletonInnerObject singletonInnerObject = new SingletonInnerObject();
}
public static SingletonInnerObject getInstance(){
return InnerObject.singletonInnerObject;
}
}
