享元模式

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定义：使用享元对象可有效的支持大量的细粒度的对象

类图：

代码：

public abstract class Flyweight {

	private String intrinsic;
	
	protected final String extrinsic;
	
	public Flyweight(String extrinsic){
		this.extrinsic = extrinsic;
	}
	
	public abstract void operator();
	
	public String getInstrinsic(){
		return intrinsic;
	}
	
	public void setInstrinsic(String instrinsic){
		this.intrinsic = instrinsic;
	}
}

public class ConcreteFlyweight1 extends Flyweight{


	public ConcreteFlyweight(String extrinsic) {
		super(extrinsic);
		// TODO Auto-generated constructor stub
	}

	@Override
	public void operator() {
		// TODO Auto-generated method stub
		
	}

}

public class ConcreteFlyweight2 extends Flyweight{


	public ConcreteFlyweight(String extrinsic) {
		super(extrinsic);
		// TODO Auto-generated constructor stub
	}

	@Override
	public void operator() {
		// TODO Auto-generated method stub
		
	}

}

public class FlyweightFactory {

	private static HashMap<String,Flyweight> pool = new HashMap<String,Flyweight>();
	
	public static Flyweight getFlyweight(String extrinsic){
		Flyweight flyweight = null;
		if(pool.containsKey(extrinsic)){
			flyweight = pool.get(extrinsic);
		}else{
			flyweight = new ConcreteFlyweight1(extrinsic);
			pool.put(extrinsic, flyweight);
		}
		return flyweight;
	}
}

大大减少应用程序创建的对象

缺点：

线程安全

享元模式

标签：

原文地址：http://blog.csdn.net/renpengddxx/article/details/52159509