设计模式——原型模式

/**
 * 产品生成管理器
 * @author maikec
 * @date 2019/5/11
 */
public final class ProductManager {
    private final Map<String, Product> productMap = Collections.synchronizedMap(new HashMap<>(  ));
    public void register(Product product){
        productMap.put( product.getClass().getSimpleName(),product );
    }
    public Product create(Product product){
        Product result = productMap.get( product.getClass().getSimpleName() );
        if(null == result){
            register( product );
            result = productMap.get( product.getClass().getSimpleName() );
        }
        return result.createClone();
    }
}

/**
 * 原型类
 * @author maikec
 * @date 2019/5/11
 */
public interface Product extends Cloneable {
    void use();

    /**
     * 克隆
     * @return
     */
    Product createClone();
}

/**
 * @author maikec
 * @date 2019/5/11
 */
public class CloneFailureException extends RuntimeException {
    public CloneFailureException(){
        super("clone failure");
    }
    public CloneFailureException(String msg){
        super(msg);
    }
}

/**
 * @author maikec
 * @date 2019/5/11
 */
public class MessageProduct implements Product {
    @Override
    public void use() {
        System.out.println( "MessageProduct" );
    }

    @Override
    public MessageProduct createClone() {
        try {
            return (MessageProduct) clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
            throw new CloneFailureException(  );
        }
    }
}

/**
 * @author maikec
 * @date 2019/5/11
 */
public class UnderlineProduct implements Product {
    @Override
    public void use() {
        System.out.println( "UnderlineProduct" );
    }

    @Override
    public UnderlineProduct createClone() {
        try {
            return (UnderlineProduct) clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
            throw new CloneFailureException();
        }
    }
}

/**
 * @author maikec
 * @date 2019/5/11
 */
public class PrototypeDemo {
    public static void main(String[] args) {
        ProductManager manager = new ProductManager();
        manager.register( new UnderlineProduct() );
        manager.register( new MessageProduct() );

        manager.create(  new UnderlineProduct()  ).use();
        manager.create(  new MessageProduct()  ).use();
    }
}