spring -- 4、SpringAOP基本使用

野性酷女 2023-02-23 08:53 17阅读 0赞

**目录**

1、AOP:将某段代码动态切入到指定方法的指定位置进行运行（代理）

案例一：

方式一：（普通方式）

方式二：（AOP方式）

方式三：（动态代理，常用方式）

案例二：

反射：

一般这样写：

--------------------

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70][]

![20200706214140253.png][]

**AOP：**Aspect Oriented Programming 面向切面编程

**OOP：**Object Oriented Programming 面向对象编程

# 1、**AOP:将****某段代码动态****切入到****指定方法****的****指定位置****进行运行（代理）** #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 1][]  ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 2][]

![20200706214140224.png][]

## **案例一：** ##

### **方式一：（普通方式）** ###

![20200706214140196.png][]

**java****文件：****Calculator****（计算器）**

public interface Calculator {
        public Integer add(Integer i,Integer j);
        public Integer sub(Integer i,Integer j);
        public Integer mul(Integer i,Integer j);
        public Integer div(Integer i,Integer j);
    }

**java****文件：****MyCalculator****（计算器）**

@Service
    public class MyCalculator implements Calculator {
        public Integer add(Integer i, Integer j) {
            Integer result = i+j;
            return result;
        }
        public Integer sub(Integer i, Integer j) {
            Integer result = i-j;
            return result;
        }
        public Integer mul(Integer i, Integer j) {
            Integer result = i*j;
            return result;
        }
        public Integer div(Integer i, Integer j) {
            Integer result = i/j;
            return result;
        }
    }

**java****文件：****MyTest****（测试）**

public class MyTest {
        @Test
        public void test01() throws NoSuchMethodException {
            MyCalculator myCalculator = new MyCalculator();
            System.out.println(myCalculator.add(1, 2)); 
    }

**========================================================**

### **方式二：（AOP方式）** ###

![20200706214406655.png][]![20200706214412327.png][]

**java****文件：****LogUtil****（日志工具）**

![20200706214429663.png][]

![20200706214437315.png][]

**j****ava****文件：****MyCalculator****（计算器）**

**添加：**

@Service
    public class MyCalculator implements Calculator {
        public Integer add(Integer i, Integer j){
            LogUtil.start(i,j); //开始
            Integer result = i+j;
            LogUtil.stop(result); //结束
            return result;
        }
        public Integer sub(Integer i, Integer j) {
            LogUtil.start(i,j); //开始
            Integer result = i-j;
            LogUtil.stop(result); //结束
            return result;
        }
        public Integer mul(Integer i, Integer j) {
            LogUtil.start(i,j); //开始
            Integer result = i*j;
            LogUtil.stop(result); //结束
            return result;
        }
        public Integer div(Integer i, Integer j) {
            LogUtil.start(i,j); //开始
            Integer result = i/j;
            LogUtil.stop(result); //结束
            return result;
        }
    }

![20200706214524965.png][]

**j****ava****文件：****MyCalculator****（计算器）**

**添加：**

@Service
    public class MyCalculator implements Calculator {
        public Integer add(Integer i, Integer j) throws NoSuchMethodException {
    添加：  Method add = MyCalculator.class.getMethod("add", Integer.class, Integer.class);
            LogUtil.start(add,i,j); //开始
            Integer result = i+j;
            LogUtil.stop(result); //结束
            return result;
        }
        public Integer sub(Integer i, Integer j) throws NoSuchMethodException {
    添加：  Method sub = MyCalculator.class.getMethod("sub", Integer.class, Integer.class);
            LogUtil.start(sub,i,j); //开始
            Integer result = i-j;
            LogUtil.stop(result); //结束
            return result;
        }
        public Integer mul(Integer i, Integer j) throws NoSuchMethodException {
    添加：  Method mul = MyCalculator.class.getMethod("mul", Integer.class, Integer.class);
            LogUtil.start(mul,i,j); //开始
            Integer result = i*j;
            LogUtil.stop(result); //结束
            return result;
        }
        public Integer div(Integer i, Integer j) throws NoSuchMethodException {
    添加：  Method div = MyCalculator.class.getMethod("div", Integer.class, Integer.class);
            LogUtil.start(div,i,j); //开始
            Integer result = i/j;
            LogUtil.stop(result); //结束
            return result;
        }
    }

**java****文件：****LogUtil****（日志工具）**

![20200706214618752.png][]

**java****文件：****Calculator****（计算器）**

![20200706214628925.png][] ![20200706214641528.png][]

**java****文件：****MyTest****（测试）**

![20200706214654359.png][]![20200706214657251.png][]

**========================================================**

### **方式三：（动态代理，常用方式）** ###

![20200706214720194.png][]

**java****文件：****CalculatorProxy****（计算器代理）**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 3][]

**java****文件：****MyTest****（测试）**

**加入：**

Calculator calculator = CalculatorProxy.getCalculator (new MyCalculator());
        calculator.add(1, 1);

![20200706214757483.png][]

**j****ava****文件：****MyCalculator****（计算器）**

**关掉：**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 4][]

**java****文件：****MyTest****（测试）**

Calculator calculator = (Calculator) CalculatorProxy.getCalculator (new MyCalculator());
            System.out.println(calculator.add(1, 1));
            calculator.sub(1,1);
            calculator.mul(1,1);
            calculator.div(1,1); //如果改（1,0），该行数据会出错

![20200706214837590.png][]

**如果改（1,0）：**

**java****文件：****CalculatorProxy****（计算器代理）**

public class CalculatorProxy {
    
        public static Calculator getCalculator ( final Calculator calculator){
            //获取被代理对象的类加载器
            ClassLoader loader = calculator.getClass().getClassLoader();
            //被代理对象的所有接口
            Class<?>[] interfaces = calculator.getClass().getInterfaces();
            //用来执行被代理类需要执行的方法
            InvocationHandler handler = new InvocationHandler() {
                public Object invoke(Object proxy（代理）, Method method（方法）, Object[] args（参数）) throws Throwable {
                   Object result = null;
                   try{
    ================================ 只改这里 =====================================
                       System.out.println(method.getName()+"方法开始执行，参数列表是："+ Arrays.asList(args));
                       //开始调用被代理类的方法
                       result = method.invoke(calculator,args);
                       System.out.println(method.getName()+"方法执行完成，结果是："+result);
    ===============================================================================
                   }catch (Exception e){
                       System.out.println(method.getName()+"方法抛出异常："
    +e.getMessage());
                       LogUtil.logException(method,e);
                   }finally {
                       System.out.println(method.getName()+"方法执行结束。。。。。over");
                       LogUtil.logFinally(method);
                   }
                   return result;
                }
            };
            Object o = Proxy.newProxyInstance(loader, interfaces, handler);
            return (Calculator) o; 
        }
    }

**//写了处理异常后，解决此问题，但是只是跳过了异常**

![20200706214912129.png][]

**解决方式：**

**java****文件：****CalculatorProxy****（计算器代理）**

public class CalculatorProxy {
    
        public static Calculator getCalculator( final Calculator calculator){
            //获取被代理对象的类加载器
            ClassLoader loader = calculator.getClass().getClassLoader();
            //被代理对象的所有接口
            Class<?>[] interfaces = calculator.getClass().getInterfaces();
            //用来执行被代理类需要执行的方法
            InvocationHandler handler = new InvocationHandler() {
                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                   Object result = null;
                   try{
    ================================ 只改这里 =====================================
                 开始：LogUtil.start(method,args);
                       //开始调用被代理类的方法
                       result = method.invoke(calculator,args);
                 结束：LogUtil.stop(method,result);
                   }catch (Exception e){
                       System.out.println(method.getName()+"方法抛出异常："
    +e.getMessage());
                       LogUtil.logException(method,e);
                   }finally {
                       System.out.println(method.getName()+"方法执行结束。。。。。over");
                       LogUtil.logFinally(method);
                   }
    ===============================================================================
                   return result;
                }
            };
            Object o = Proxy.newProxyInstance(loader, interfaces, handler);
            return (Calculator) o; 
        }
    }

**java****文件：****LogUtil****（日志工具）**

**添加：**

![20200706214944901.png][]![20200706214948438.png][]** //该行未报错**

![20200706215006409.png][]

**java****文件：****MyTest****（测试）**

![20200706215013815.png][]

**===========================================================**

## **案例二：** ##

![2020070621503174.png][]

### **反射：** ###

**java****文件：****SecondCalculator****（****第二个计算器）**

public class SecondCalculator implements Calculator {
        public Integer add(Integer i, Integer j) throws NoSuchMethodException {
            return null;
        }
        public Integer sub(Integer i, Integer j) throws NoSuchMethodException {
            return null;
        }
        public Integer mul(Integer i, Integer j) throws NoSuchMethodException {
            return null;
        }
        public Integer div(Integer i, Integer j) throws NoSuchMethodException {
            return null;
        }
    }

**java****文件：****MyInterface****（接口）**

public interface MyInterface {
        
        public void show();
    }

**java****文件：****MySubClass****（下标类）**

**添加：**

![20200706215136514.png][]

**java****文件：****MyTest****（测试）**

**添加：**

![20200706215146780.png][]

**1****、**必须要有接口，如果没有接口，不能使用，这种方式是用jdk提供的reflect（反射）包下的类

**2****、**但是在生产环境中不能保证每个类都有实现的接口，所以有第二种方式cglib（基于类的代理），cglib在实现的时候有没有接口都无所谓  
**3****、**在spring中使用了两种动态代理的方式，一种是jdk提供的reflect（反射）下面写的，另外一种就是cglib（基于类的代理）

**java****文件：****MyTest****（测试）**

![20200706215244193.png][]![20200706215247487.png][]

**========================================================**

![20200706215259639.png][]

### **一般这样写：** ###

**java****文件：****DynamicProxy****（动态代理）**

public class DynamicProxy implements InvocationHandler {
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
            return null;
        }
    }

**=============================================================**

**java****文件：****MyInterface****（接口）**

public interface MyInterface {
    
        public void show(Integer i);
    }

**java****文件：****MySubClass****（下标类）**

public class MySubClass implements MyInterface {
        public void show(Integer i) {
            System.out.println("show.......");
        }
    }

![20200706215428111.png][]![20200706215430993.png][]

**java****文件：****MyTest****（测试）**

System.out.println("------------------");
      MyInterface proxy = (MyInterface) CalculatorProxy.getProxy(new MySubClass());
      proxy.show(100);
    }

![20200706215502470.png][]

**=======================================================================**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 5][]

![2020070621552015.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200706214141192.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ==,size_16,color_FFFFFF,t_70
[20200706214140253.png]: https://img-blog.csdnimg.cn/20200706214140253.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/2020070621414183.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200706214140942.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ==,size_16,color_FFFFFF,t_70
[20200706214140224.png]: https://img-blog.csdnimg.cn/20200706214140224.png
[20200706214140196.png]: https://img-blog.csdnimg.cn/20200706214140196.png
[20200706214406655.png]: https://img-blog.csdnimg.cn/20200706214406655.png
[20200706214412327.png]: https://img-blog.csdnimg.cn/20200706214412327.png
[20200706214429663.png]: https://img-blog.csdnimg.cn/20200706214429663.png
[20200706214437315.png]: https://img-blog.csdnimg.cn/20200706214437315.png
[20200706214524965.png]: https://img-blog.csdnimg.cn/20200706214524965.png
[20200706214618752.png]: https://img-blog.csdnimg.cn/20200706214618752.png
[20200706214628925.png]: https://img-blog.csdnimg.cn/20200706214628925.png
[20200706214641528.png]: https://img-blog.csdnimg.cn/20200706214641528.png
[20200706214654359.png]: https://img-blog.csdnimg.cn/20200706214654359.png
[20200706214657251.png]: https://img-blog.csdnimg.cn/20200706214657251.png
[20200706214720194.png]: https://img-blog.csdnimg.cn/20200706214720194.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20200706214731498.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ==,size_16,color_FFFFFF,t_70
[20200706214757483.png]: https://img-blog.csdnimg.cn/20200706214757483.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20200706214806319.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ==,size_16,color_FFFFFF,t_70
[20200706214837590.png]: https://img-blog.csdnimg.cn/20200706214837590.png
[20200706214912129.png]: https://img-blog.csdnimg.cn/20200706214912129.png
[20200706214944901.png]: https://img-blog.csdnimg.cn/20200706214944901.png
[20200706214948438.png]: https://img-blog.csdnimg.cn/20200706214948438.png
[20200706215006409.png]: https://img-blog.csdnimg.cn/20200706215006409.png
[20200706215013815.png]: https://img-blog.csdnimg.cn/20200706215013815.png
[2020070621503174.png]: https://img-blog.csdnimg.cn/2020070621503174.png
[20200706215136514.png]: https://img-blog.csdnimg.cn/20200706215136514.png
[20200706215146780.png]: https://img-blog.csdnimg.cn/20200706215146780.png
[20200706215244193.png]: https://img-blog.csdnimg.cn/20200706215244193.png
[20200706215247487.png]: https://img-blog.csdnimg.cn/20200706215247487.png
[20200706215259639.png]: https://img-blog.csdnimg.cn/20200706215259639.png
[20200706215428111.png]: https://img-blog.csdnimg.cn/20200706215428111.png
[20200706215430993.png]: https://img-blog.csdnimg.cn/20200706215430993.png
[20200706215502470.png]: https://img-blog.csdnimg.cn/20200706215502470.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ_size_16_color_FFFFFF_t_70 5]: https://img-blog.csdnimg.cn/20200706215515232.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTA0MjU2OQ==,size_16,color_FFFFFF,t_70
[2020070621552015.png]: https://img-blog.csdnimg.cn/2020070621552015.png