重新认识装饰模式--装饰模式实现AOP

package itcast.test.decorator;
/**
 * 装饰器的接口，需要和被装饰的对象实现同样的接口*/
public abstract class Dercorator implements GoodsSaleEbi {
    /**
     * 持有被装饰的组件对象*/
    protected GoodsSaleEbi ebi;
    /**
     * 通过构造方法传入被装饰对象
     * @prara, ebi被装饰的对象*/
    public Dercorator(GoodsSaleEbi ebi){
        this.ebi=ebi;
    }
}
package itcast.test.decorator;
public class CheckDecorator extends Dercorator{
    /**
     * 实现权限控制*/
    public CheckDecorator(GoodsSaleEbi ebi){
        super(ebi);
    }
    
    public boolean sale(String user,String customer,SaleModel saleModel){
        
        //简单点儿，只让张三执行这个功能
        if(!"张三".equals(user)){
            System.out.println("对不起"+user+",你没有保存销售单的权限");
            //就不用再调用被装饰的对象的功能了
            return false;
        }else{
            return this.ebi.sale(user,customer,saleModel);
        }
    }
}
package itcast.test.decorator;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
public class LogDercorator extends Dercorator{
    public LogDercorator(GoodsSaleEbi ebi){
        super(ebi);
    }
    public boolean sale(String user,String customer,SaleModel saleModel){
        //执行业务功能
        boolean f= this.ebi.sale(user, customer, saleModel);
        //执行业务功能后记录日志
        DateFormat df= new SimpleDateFormat("yyyy-MM-dd HH:mm:ss SSS");
        
        System.out.println("日志记录:"+user+"于"+df.format(new Date())+"时保存了一条销售记录，客户是"+customer+",购买记录是"+saleModel);
        
        return f;
    }
}
package itcast.test.decorator;
//商品销售管理的业务接口
public interface GoodsSaleEbi {
    /* * 保存销售信息
     * @param customer 客户
     * @param saleModel 销售数据
     * @return 是否保存成功*/
    public boolean sale(String user,String customer,SaleModel saleModel);
}
package itcast.test.decorator;
public class GoodsSaleEbo implements GoodsSaleEbi {
    @Override
    public boolean sale(String user, String customer, SaleModel saleModel) {
        System.out.println(user+"保存了"+customer+"购买"+saleModel+"的销售数据");
        return true;
    }
}
package itcast.test.decorator;
/**
 * 封装好的销售单数据对象*/
public class SaleModel {
    private String goods;
    private int saleNum;
    public String getGoods() {
        return goods;
    }
    public void setGoods(String goods) {
        this.goods = goods;
    }
    public int getSaleNum() {
        return saleNum;
    }
    public void setSaleNum(int saleNum) {
        this.saleNum = saleNum;
    }
    
    public String toString(){
        return "商品名称="+goods+",购买数量="+saleNum;
    }
    
}
package itcast.test.decorator;
public class Client {
    public static void main(String[] args){
        //得到业务接口，组合装饰器
        GoodsSaleEbi ebi = new CheckDecorator(new LogDercorator(new GoodsSaleEbo()));
        /*准备测试数据*/
        SaleModel saleModel= new SaleModel();
        saleModel.setGoods("MoTo 手机");
        saleModel.setSaleNum(2);
        
        //调用和业务功能
        ebi.sale("张三", "张三丰", saleModel);
        ebi.sale("李四", "张三丰", saleModel);
        
    }
}