站在SpringMVC源码角度分析@async失效之谜

发布于:2023-01-09 ⋅ 阅读:(455) ⋅ 点赞:(0)

1.基于Jdk动态代理纯手写@async实现异步操作
2.基于SpringAop纯手写@async实现异步操作
3.Spring中如何综合使用@Cglib与Jdk动态代理
4.站在代理分析为什么this不能经过代理类拦截?
5.错用@async会导致SpringMVC控制类无法注入,你有了解过吗?
6.站在SpringMVC源码角度分析,为什么@async异步注解会失效

设计模式的分类
创建型模式
工厂方法模式、抽象工厂模式、单例模式、建造者模式、原型模式。
结构型模式
适配器模式、装饰器模式、代理模式、外观模式、桥接模式、组合模式、享元模式
行为模式
策略模式、模板方法模式、观察者模式、迭代子模式、责任链模式、命令模式、备忘录模式、状态模式、访问者模式、中介者模式、解释器模式。
彻底搞懂代理模式实现原理
什么是代理模式
代理模式主要对我们方法执行之前与之后实现增强
代理模式应用场景
1.日志的采集
2.权限控制
3.实现aop
4.Mybatis mapper
5.Spring的事务
6.全局捕获异常
7.Rpc远程调用接口
8.代理数据源
代理模式实现的原理
代理模式主要包含三个角色,即抽象主题角色(Subject)、委托类角色(被代理角色,Proxied)以及代理类角色(Proxy),如上图所示:

抽象主题角色:可以是接口,也可以是抽象类;
委托类角色:真实主题角色,业务逻辑的具体执行者;
代理类角色:内部含有对真实对象RealSubject的引用,负责对真实主题角色的调用,并在真实主题角色处理前后做预处理和后处理。

代理模式创建方式
静态代理
静态代理需要自己人工编写代理类代码
基于接口实现方式

public class OrderServiceProxy  implements  OrderService{
    private OrderService orderService;

    public OrderServiceProxy(OrderService orderService) {
        this.orderService = orderService;
    }

    public String addOrder(String userName, String userPwd) {
        System.out.println("使用静态代理类打印日志开始:userName:" + userName + "," + userPwd);
        String result = orderService.addOrder(userName, userPwd);
        System.out.println("使用静态代理类打印日志结束:userName:" + userName + "," + userPwd);
        return result;
    }
}


public interface OrderService {
    /**
     * 需要被代理的方法
     * @return
     */
     String addOrder(String userName,String userPwd);
}


public class Test001 {
    public static void main(String[] args) {
        OrderService orderService = new OrderServiceProxy(new OrderServiceImpl());
        orderService.addOrder("mayikt","123456");
    }
}


基于继承的实现方式
public class OrderServiceProxy  extends OrderServiceImpl {
    private OrderService orderService;

    public OrderServiceProxy(OrderService orderService) {
        this.orderService = orderService;
    }

    public String addOrder(String userName, String userPwd) {
        System.out.println("使用静态代理类打印日志开始:userName:" + userName + "," + userPwd);
        String result = super.addOrder(userName, userPwd);
        System.out.println("使用静态代理类打印日志结束:userName:" + userName + "," + userPwd);
        return result;
    }
}

动态代理与静态代理的区别

动态代理不需要写代理类对象,通过程序自动生成,而静态代理需要我们自己写代理类对象。

动态代理
动态代理是在实现阶段不用关心代理类,而在运行阶段才指定哪一个对象。
动态代理类的源码是在程序运行期间由JVM根据反射等机制动态的生成 。

Jdk动态代理
JDK动态代理的一般步骤如下:
1.创建被代理的接口和类;
2.实现InvocationHandler接口,对目标接口中声明的所有方法进行统一处理;
3.调用Proxy的静态方法,创建代理类并生成相应的代理对象;


实现原理:利用拦截器机制必须实现InvocationHandler接口中的invoke方法实现对
我们的目标方法增强。

public class JdkInvocationHandler implements InvocationHandler {
    /**
     * 目标对象
     */
    private Object target;

    public JdkInvocationHandler(Object target) {
        this.target = target;
    }

    /**
     * @param proxy  使用jdk程序生成的代理类
     * @param method 目标方法
     * @param args   方法需要传递的参数
     * @return
     */
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("使用Jdk动态代理打印日志开始" + args[0]);
        Object result = method.invoke(target, args);
        System.out.println("使用Jdk动态代理打印日志结束" + args[1]);
        return result;
    }

    /**
     * 生成代理类
     *
     * @param <T>
     * @return
     */
    public <T> T getProxy() {
        return (T) Proxy.newProxyInstance(target.getClass().getClassLoader(),
                target.getClass().getInterfaces(), this);
    }

}






public class JdkInvocationHandler implements InvocationHandler {
    /**
     * 目标对象
     */
    private Object target;

    public JdkInvocationHandler(Object target) {
        this.target = target;
    }

    /**
     * @param proxy  使用jdk程序生成的代理类
     * @param method 目标方法
     * @param args 方法需要传递的参数
     * @return
     */
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("使用Jdk动态代理打印日志开始" + args[0]);
        Object result = method.invoke(target, args);
        System.out.println("使用Jdk动态代理打印日志结束" + args[1]);
        return result;
    }

    public <T> T getProxy() {
        return (T) Proxy.newProxyInstance(target.getClass().getClassLoader(),
                target.getClass().getInterfaces(), this);
    }

}


JdkInvocationHandler jdkInvocationHandler = new JdkInvocationHandler(new OrderServiceImpl());
OrderServiceImpl orderService = jdkInvocationHandler.getProxy();
orderService.addOrder("mayikt", "meite");


加上该代码:


1.获取代理的生成的class文件
System.getProperties().put("sun.misc.ProxyGenerator.saveGeneratedFiles", "true");

2.使用反编译工具该Proxy0.class


注意:继承了Proxy类,实现了代理的接口,由于java不能多继承,这里已经继承了Proxy类了,不能再继承其他的类,所以JDK的动态代理不支持对实现类的代理,只支持接口的代理。

纯手写Jdk动态代理

思路分析:
1.定义InvocationHandler类 回调方法
2.使用java反射技术获取接口下所有的方法,拼接 $Proxy0.java代码
3.在将$Proxy0.java编译成class文件,读取到内存中


public class $Proxy0 implements com.mayikt.service.OrderService {

    private MayiktJdkInvocationHandler h;
    private static Method m3;

    public $Proxy0(MayiktJdkInvocationHandler mayiktJdkInvocationHandler) {
        this.h = mayiktJdkInvocationHandler;
    }

    @Override
    public String addOrder(String ver1, String var2) {
        try {
            return (String) h.invoke(this, m3, new Object[]{ver1, var2});
        } catch (RuntimeException | Error var4) {
            throw var4;
        } catch (Throwable var5) {
            throw new UndeclaredThrowableException(var5);
        }
    }

    static {
        try {
            m3 = Class.forName("com.mayikt.service.OrderService").getMethod("addOrder", Class.forName("java.lang.String"), Class.forName("java.lang.String"));
        } catch (NoSuchMethodException var2) {
            throw new NoSuchMethodError(var2.getMessage());
        } catch (ClassNotFoundException var3) {
            throw new NoClassDefFoundError(var3.getMessage());
        }
    }
}


public class MyJdkInvocationHandler implements MayiktJdkInvocationHandler {
    /**
     * 目标对象
     */
    private Object target;

    public MyJdkInvocationHandler(Object target) {
        this.target = target;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("使用Jdk动态代理打印日志开始" + args[0]);
        Object result = method.invoke(target, args);
        System.out.println("使用Jdk动态代理打印日志结束" + args[1]);
        return result;
    }
    public <T> T getProxy() {
        return (T) new $Proxy0(this);
    }
}

MyJdkInvocationHandler myJdkInvocationHandler = new MyJdkInvocationHandler(new OrderServiceImpl());
OrderService orderService = myJdkInvocationHandler.getProxy();
orderService.addOrder("mayikt", "meite");

public class MyProxy {
    private static String rt = "\r\t";

    public static Object newProxyInstance(JavaClassLoader classLoader, Class classInfo, MayiktInvocationHandler mayiktInvocationHandler) {
        try {
            // 1.拼接java代理代理源代码
            Method[] methods = classInfo.getMethods();
            String proxyClass = "package com.mayikt.service;" + rt
                    + "import java.lang.reflect.Method;" + rt
                    + "import com.mayikt.service.proxy.MayiktInvocationHandler;" + rt
                    + "import java.lang.reflect.UndeclaredThrowableException;" + rt
                    + "public class $Proxy0 implements " + classInfo.getName() + "{" + rt
                    + "MayiktInvocationHandler h;" + rt
                    + "public $Proxy0(MayiktInvocationHandler h)" + "{" + rt
                    + "this.h= h;" + rt + "}"
                    + getMethodString(methods, classInfo) + rt + "}";
            // 2.将该源代码写入到本地文件中
            String filename = "d:/code/$Proxy0.java";
            File f = new File(filename);
            FileWriter fw = new FileWriter(f);
            fw.write(proxyClass);
            fw.flush();
            fw.close();
            // 3.编译为class文件
            JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
            StandardJavaFileManager fileMgr = compiler.getStandardFileManager(null, null, null);
            Iterable units = fileMgr.getJavaFileObjects(filename);
            JavaCompiler.CompilationTask t = compiler.getTask(null, fileMgr, null, null, null, units);
            t.call();
            fileMgr.close();
            // 4.将class文件加入到内存中
            Class proxy0Class = classLoader.findClass("$Proxy0");
            //5.使用java反射机制给函数中赋值
            Constructor m = proxy0Class.getConstructor(MayiktInvocationHandler.class);
            Object object = m.newInstance(mayiktInvocationHandler);
            return object;
        } catch (Exception e) {
            return null;
        }
    }

    public static String getMethodString(Method[] methods, Class intf) {
        String proxyMe = "";

        for (Method method : methods) {
            Class<?>[] parameterTypes = method.getParameterTypes();
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < parameterTypes.length; i++) {
                sb.append(parameterTypes[i].getName() + " ver" + (i + 1));
                if (i < parameterTypes.length - 1) {
                    sb.append(" ,");
                }
            }
            String parameterStr = sb.toString();
            proxyMe = "public " + method.getReturnType().getName() + " " + method.getName() + " ( " + parameterStr + " ) { " +
                    "try {   Method m3 = Class.forName(\"com.mayikt.service.OrderService\").getMethod(\"addOrder\", Class.forName(\"java.lang.String\"), Class.forName(\"java.lang.String\"));" +
                    "return (String) h.invoke(this, m3, new Object[]{ver1, ver2}); } catch (RuntimeException | Error var4) {  throw var4;  } catch (Throwable var5) {   throw new UndeclaredThrowableException(var5); } " +
                    "" +
                    " } ";

        }
        return proxyMe;
    }

    public static void main(String[] args) {
        newProxyInstance(null, OrderService.class, null);
    }
}




public class JavaClassLoader extends ClassLoader {

    private File classPathFile;

    public JavaClassLoader(){
//        String classPath=JavaClassLoader.class.getResource("").getPath();
        String classPath="D:\\code";
        this.classPathFile=new File(classPath);
    }

    @Override
    public Class<?> findClass(String name) throws ClassNotFoundException {
        String className= JavaClassLoader.class.getPackage().getName()+"."+name;
        if(classPathFile!=null){
          File classFile=new File(classPathFile,name.replaceAll("\\.","/")+".class");
          if(classFile.exists()){
              FileInputStream in=null;
              ByteArrayOutputStream out=null;
              try {
                  in=new FileInputStream(classFile);
                  out=new ByteArrayOutputStream();
                  byte[] buff=new byte[1024];
                  int len;
                  while ((len=in.read(buff))!=-1){
                     out.write(buff,0,len);
                  }
                  return defineClass(className,out.toByteArray(),0,out.size());
              }catch (Exception e){
                  e.printStackTrace();
              }finally {
                  if(in!=null){
                      try {
                          in.close();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  }
                  if(out!=null){
                      try {
                          out.close();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  }
              }
          }
        }
        return null;
    }
}


public class MyJdkInvocationHandler implements MayiktJdkInvocationHandler {
    /**
     * 目标对象
     */
    private Object target;

    public MyJdkInvocationHandler(Object target) {
        this.target = target;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("使用Jdk动态代理打印日志开始" + args[0]);
        Object result = method.invoke(target, args);
        System.out.println("使用Jdk动态代理打印日志结束" + args[1]);
        return result;
    }


    public <T> T getProxy() {
        return (T) MyProxy.newProxyInstance(new JavaClassLoader(), target.getClass().getInterfaces()[0], this);
    }
}


CGLIB动态代理
利用asm字节码技术,生成子类实现对目标方法实现增强
实现方式
Maven依赖
<dependencies>
    <dependency>
        <groupId>cglib</groupId>
        <artifactId>cglib</artifactId>
        <version>3.2.12</version>
    </dependency>
</dependencies>


核心代码
```java
public class CglibMethodInterceptor implements MethodInterceptor {
    public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
        System.out.println("<<<<<日志收集开始...>>>>>>>");
        Object reuslt = proxy.invokeSuper(obj, args);
        System.out.println("<<<<<日志收集结束...>>>>>>>");
        return reuslt;
    }
}
System.setProperty(DebuggingClassWriter.DEBUG_LOCATION_PROPERTY, "D:\\code");
CglibMethodInterceptor cglibMethodInterceptor = new CglibMethodInterceptor();
Enhancer enhancer = new Enhancer();
// 设置代理类的付类
enhancer.setSuperclass(MemberServiceImpl.class);
// 设置回调对象
enhancer.setCallback(cglibMethodInterceptor);
// 创建代理对象
MemberServiceImpl orderServiceImpl = (MemberServiceImpl) enhancer.create();
orderServiceImpl.getMember();

Cglib动态代理底层源码分析
Cglib依赖于ASM字节码技术,直接生成class文件,在采用类加载器读取到程序中,
使用fastclass对被代理类的方法建立索引文件不需要依赖于反射查找到目标方法,所以效率比Jdk动态代理要高。

public class OrderServiceImpl$$EnhancerByCGLIB$$1dd3a71c extends OrderServiceImpl {

    static void CGLIB$STATICHOOK1() throws ClassNotFoundException {
        Method amethod[];
        Method amethod1[];
        CGLIB$THREAD_CALLBACKS = new ThreadLocal();
        CGLIB$emptyArgs = new Object[0];
        Class class1 = Class.forName("com.mayikt.service.impl.OrderServiceImpl$$EnhancerByCGLIB$$1dd3a71c");
        Class class2;
        amethod = ReflectUtils.findMethods(new String[]{
                "addOrder", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;"
        }, (class2 = Class.forName("com.mayikt.service.impl.OrderServiceImpl")).getDeclaredMethods());
        Method[] _tmp = amethod;
        CGLIB$addOrder$0$Method = amethod[0];
        CGLIB$addOrder$0$Proxy = MethodProxy.create(class2, class1, "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;", "addOrder", "CGLIB$addOrder$0");
        amethod1 = ReflectUtils.findMethods(new String[]{
                "equals", "(Ljava/lang/Object;)Z", "toString", "()Ljava/lang/String;", "hashCode", "()I", "clone", "()Ljava/lang/Object;"
        }, (class2 = Class.forName("java.lang.Object")).getDeclaredMethods());
        Method[] _tmp1 = amethod1;
        CGLIB$equals$1$Method = amethod1[0];
        CGLIB$equals$1$Proxy = MethodProxy.create(class2, class1, "(Ljava/lang/Object;)Z", "equals", "CGLIB$equals$1");
        CGLIB$toString$2$Method = amethod1[1];
        CGLIB$toString$2$Proxy = MethodProxy.create(class2, class1, "()Ljava/lang/String;", "toString", "CGLIB$toString$2");
        CGLIB$hashCode$3$Method = amethod1[2];
        CGLIB$hashCode$3$Proxy = MethodProxy.create(class2, class1, "()I", "hashCode", "CGLIB$hashCode$3");
        CGLIB$clone$4$Method = amethod1[3];
        CGLIB$clone$4$Proxy = MethodProxy.create(class2, class1, "()Ljava/lang/Object;", "clone", "CGLIB$clone$4");
    }

    final String CGLIB$addOrder$0(String s, String s1) {
        return super.addOrder(s, s1);
    }


    final boolean CGLIB$equals$1(Object obj) {
        return super.equals(obj);
    }


    final String CGLIB$toString$2() {
        return super.toString();
    }


    final int CGLIB$hashCode$3() {
        return super.hashCode();
    }


    public static void CGLIB$SET_THREAD_CALLBACKS(Callback acallback[]) {
        CGLIB$THREAD_CALLBACKS.set(acallback);
    }

    public final String addOrder(String paramString1, String paramString2) {
        MethodInterceptor tmp4_1 = this.CGLIB$CALLBACK_0;
        if (tmp4_1 == null) {

            CGLIB$BIND_CALLBACKS(this);
        }
        try {
            MethodInterceptor tmp17_14 = this.CGLIB$CALLBACK_0;
            if (tmp17_14 != null) {
                return (String) tmp17_14.intercept(this, CGLIB$addOrder$0$Method, new Object[]{paramString1, paramString2}, CGLIB$addOrder$0$Proxy);
            }
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        }
        return super.addOrder(paramString1, paramString2);
    }


    public Object newInstance(Callback acallback[]) {
        CGLIB$SET_THREAD_CALLBACKS(acallback);
        CGLIB$SET_THREAD_CALLBACKS(null);
        return new OrderServiceImpl$$EnhancerByCGLIB$$1dd3a71c();
    }

    public Object newInstance(Callback callback) {
        CGLIB$SET_THREAD_CALLBACKS(new Callback[]{
                callback
        });
        CGLIB$SET_THREAD_CALLBACKS(null);
        return new OrderServiceImpl$$EnhancerByCGLIB$$1dd3a71c();
    }


    public void setCallback(int i, Callback callback) {
        switch (i) {
            case 0: // '\0'
                CGLIB$CALLBACK_0 = (MethodInterceptor) callback;
                break;
        }
    }


    private boolean CGLIB$BOUND;
    public static Object CGLIB$FACTORY_DATA;
    private static ThreadLocal CGLIB$THREAD_CALLBACKS = null;
    private static final Callback CGLIB$STATIC_CALLBACKS[] = null;
    private MethodInterceptor CGLIB$CALLBACK_0;
    private static Object CGLIB$CALLBACK_FILTER;
    private static Method CGLIB$addOrder$0$Method = null;
    private static MethodProxy CGLIB$addOrder$0$Proxy = null;
    private static Object[] CGLIB$emptyArgs = null;
    private static Method CGLIB$equals$1$Method = null;
    private static MethodProxy CGLIB$equals$1$Proxy = null;
    private static Method CGLIB$toString$2$Method = null;
    private static MethodProxy CGLIB$toString$2$Proxy = null;
    private static Method CGLIB$hashCode$3$Method = null;
    private static MethodProxy CGLIB$hashCode$3$Proxy = null;
    private static Method CGLIB$clone$4$Method = null;
    private static MethodProxy CGLIB$clone$4$Proxy = null;

    static {
        try {
            CGLIB$STATICHOOK1();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    public OrderServiceImpl$$EnhancerByCGLIB$$1dd3a71c() {
        CGLIB$BIND_CALLBACKS(this);
    }

    private void CGLIB$BIND_CALLBACKS(OrderServiceImpl$$EnhancerByCGLIB$$1dd3a71c orderServiceImpl$$EnhancerByCGLIB$$1dd3a71c) {
    }
}

FastClass机制

public class MayiktFastclass {

    /**
     * 根据索引查找到目标方法
     *
     * @param index
     * @param obj
     * @param args
     * @return
     */
    public static Object invoke(int index, Object obj, Object[] args) {
        OrderServiceImpl orderService = (OrderServiceImpl) obj;
        switch (index) {
            case 1:
                return orderService.addOrder(String.valueOf(args[0]), String.valueOf(args[1]));
        }
        return null;
    }

    /**
     * 根据签名简历索引文件
     *
     * @param sign
     * @return
     */
    public static int getIndex(String sign) {
        switch (sign.hashCode()) {
            case 1763340254:
                return 1;
            case 20:
                return 2;
        }
        return -1;
    }

    public static void main(String[] args) {
        System.out.println("addOrder()String,String".hashCode());
        Object result = invoke(getIndex("addOrder()String,String"), new OrderServiceImpl(), new String[]{"mayikt", "meite"});
    }
}

Jdk与Cglib动态代理的区别
1.Jdk动态代理利用反射技术生成匿名的代理类走InvokeHandler回调方法实现增强,同时也是一种基于接口的方式实现代理。
2.Cglib动态代理利用asm字节码技术生成一个子类覆盖其中的方法实现增强,同时采用fastClass机制对整个代理类建立索引比反射效率要高
3.在Spring中如果需要被代理的对象如果实现了接口采用Jdk动态代理,没有实现接口则使用Cglib动态代理。

Springboot @async失效之谜
@async异步主要 在方法加上该注解可以实现异步的效果

注意:
1.必须将异步回调的方法单独使用一个类调用或者从容器中获取对象,如果在没有调用代理类情况下
@async否则会失效。
2.如果SpringMVC控制类实现了接口,在该类中加上个了@Async会导致将该对象注入到
SpringMVC容器中 AbstractHandlerMethodMapping

@RestController
@Slf4j
public class MemberServiceImpl {
    @Autowired
    private MemberServiceManage memberServiceManage;

    @GetMapping("/addUser")
    public String addUser() {
        log.info(">>>流程1");
        memberServiceManage.addUserLog();
        log.info(">>>流程3");
        return "success";
    }
}


@Component
public class SpringUtils implements ApplicationContextAware {


    private static ApplicationContext applicationContext = null;

    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }


    public static <T> T getBean(String beanId) {
        return (T) applicationContext.getBean(beanId);
    }

    public static <T> T getBean(Class<T> requiredType) {
        return (T) applicationContext.getBean(requiredType);
    }


    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringUtils.applicationContext = applicationContext;
    }

}

4.方法名称必须要是公有的
基于Aop手写异步注解框架

自定义注解

Java注解是Jdk1.5推出一个重大特性 可以标记在类、方法、属性上面

内置注解:
1.@Override - 检查该方法是否是重写方法。如果发现其父类,或者是引用的接口中并没有该方法时,会报编译错误。
2.@Deprecated - 标记过时方法。如果使用该方法,会报编译警告。

元注解:
@Retention - 标识这个注解怎 么保存,是只在代码中,还是编入class文件中,或者是在运行时可以通过反射访问。
@Documented - 标记这些注解是否包含在用户文档中。
@Target - 标记这个注解应该是哪种 Java 成员。
@Inherited - 标记这个注解是继承于哪个注解类(默认 注解并没有继承于任何子类)

基于Jdk动态代理手写异步注解
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExtAsync {
}

public class JdkInvocationHandler implements InvocationHandler {
    /**
     * 目标对象
     */
    private Object target;
    private ExecutorService executorService;

    public JdkInvocationHandler(Object target) {
        this.target = target;
        executorService = Executors.newFixedThreadPool(10);
    }

    public Object invoke(Object proxy, final Method method, final Object[] args) throws Throwable {
        // 执行我们的目标方法
//        ExtAsync extAsync = method.getDeclaredAnnotation(ExtAsync.class);
        // 获取对应子类上是否有加上 @注解ExtAsync
        Method methodImpl = target.getClass().getMethod(method.getName(), method.getParameterTypes());
        ExtAsync extAsync = methodImpl.getDeclaredAnnotation(ExtAsync.class);
        Object result = null;


        if (extAsync != null) {
            // 则开启线程执行目标方法
            try {
                executorService.execute(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            method.invoke(target, args);
                            return;
                        } catch (IllegalAccessException e) {
                            e.printStackTrace();
                        } catch (InvocationTargetException e) {
                            e.printStackTrace();
                        }
                    }
                });

            } catch (Exception e) {

            }
        } else {
            result = method.invoke(target, args);
        }
        return result;
    }

    /**
     * 生成代理类
     *
     * @param <T>
     * @return
     */
    public <T> T getProxy() {
        return (T) Proxy.newProxyInstance(target.getClass().getClassLoader(),
                target.getClass().getInterfaces(), this);
    }
}
OrderServiceImpl orderServiceImpl = new OrderServiceImpl();
JdkInvocationHandler jdkInvocationHandler = new JdkInvocationHandler(orderServiceImpl);
OrderService orderService = jdkInvocationHandler.getProxy();
orderServiceImpl.setProxy(orderService);
orderService.addOrder();



基于SpringAop动态代理手写异步注解

@Component
@Slf4j
@Aspect
public class ExtAsyncAop {

    private ExecutorService executorService;

    public ExtAsyncAop() {
        executorService = Executors.newFixedThreadPool(2);
    }

    @Around(value = "@annotation(com.mayikt.service.ext.ExtAsync)")
    public void doBefore(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println(">>>开始拦截到注解");
        executorService.execute(new Runnable() {
            @SneakyThrows
            @Override
            public void run() {
                joinPoint.proceed();
            }
        });


    }
}

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