4 原始模型(Prototype)模式

1. 含义

通过给出一个原型对象来指明所要创建的对象的类型,然后用复制这个原型对象的方法创建出更多同类型的对象.

2.类图

简单形式

登记形式

3.类代码

    简单形式

/**
 * 抽象原型角色
 *
 */
public interface Prototype extends Cloneable {
	Object clone();
}


/**
 * 具体原型角色
 */
public class ConcretePrototype implements Prototype{
	public Object clone() {
		try{
			return (Prototype)super.clone();
		}catch(CloneNotSupportedException e){
			return null;
			
		}
	}
}


/**
 * 客户角色
 */
public class Client {
	private Prototype prototype;

	public void operation(Prototype example) {
		prototype = (Prototype) example.clone();
		S.s(example);
		S.s(prototype);
	}

	public static void main(String[] a) {
		Client c = new Client();
		c.operation(new ConcretePrototype());

	}
}

  登记形式

/**
 * 抽象原型角色
 *
 */
public interface Prototype extends Cloneable {
	Object clone();
}


/**
 * 具体原型角色
 */
public class ConcretePrototype implements Prototype {
	@SuppressWarnings("finally")
	public synchronized Object clone() {
		Prototype temp = null;

		try {
			temp = (Prototype) super.clone();
			return temp;
		} catch (CloneNotSupportedException e) {
			S.s("Clone failed.");

		} finally {
			return temp;
		}
	}
}


/**
 * 原型管理器角色
 */

public class PrototypeManager {
	private Vector objects = new Vector();

	public void add(Prototype p) {
		objects.add(p);
	}

	public Prototype get(int i) {
		return (Prototype) objects.get(i);
	}

	public int getSize() {
		return objects.size();
	}
}


/**
 * 客户角色
 */
public class Client {
	public PrototypeManager pm = new PrototypeManager();
	private Prototype prototype;

	public void registerPrototype() {
		prototype = new ConcretePrototype();
		Prototype copytype = (Prototype) prototype.clone();
		pm.add(copytype);
	}

	public static void main(String[] a) {
		Client c = new Client();
		c.registerPrototype();
		c.registerPrototype();
		S.s(c.pm.getSize());
	}
}

 

4. 深复制

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
 * 具体原型角色
 */
public class ConcretePrototype implements Prototype, Serializable {
	public Object clone() {
		Prototype concretePrototype = null;
		try {
			concretePrototype = (Prototype)deepClone();
			return concretePrototype;
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			return concretePrototype;
		}
	}

	/**
	 * 通过在流里读来读去的方式来实现深复制
	 * 
	 * @return
	 * @throws IOException
	 * @throws ClassNotFoundException
	 */
	public Object deepClone() throws IOException, ClassNotFoundException {
		// 将对象写到流里
		ByteArrayOutputStream bo = new ByteArrayOutputStream();
		ObjectOutputStream oo = new ObjectOutputStream(bo);
		oo.writeObject(this);
		// 从流里读回来
		ByteArrayInputStream bi = new ByteArrayInputStream(bo.toByteArray());
		ObjectInputStream oi = new ObjectInputStream(bi);
		return oi.readObject();
	}
}

 

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