上文已经讲过@EnableAsync的bean构建过程，这里继续分解@Async执行过程，以及spring 的AOP调用过程。
先上demo
public class ApiGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(ApiGatewayApplication.class, args);
AsyncTest test = BeanUtils.getBean("asyncTest");
test.test();//1
}
}
@Configuration
public class WorkPool {
@Bean("WorkPool")
public ThreadPoolTaskExecutor taskExecutor(){
ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
threadPoolTaskExecutor.initialize();
return threadPoolTaskExecutor;
}
}
@Component
public class AsyncTest {
@Async
public void test() {
System.out.printf("test");
}
}
1、这一步是下面的重点，底层是怎么调用。
private static class DynamicAdvisedInterceptor implements MethodInterceptor, Serializable {
@Nullable
public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
List2、如果没有AOP行为，直接调用原bean。
3、如果有AOP行为，构造一个 Cglib的CglibMethodInvocation 方法回调对象。
public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Cloneable {
public Object proceed() throws Throwable {
Object interceptorOrInterceptionAdvice = this.interceptorsAndDynamicMethodMatchers.get(++this.currentInterceptorIndex);
if (interceptorOrInterceptionAdvice instanceof InterceptorAndDynamicMethodMatcher) {
InterceptorAndDynamicMethodMatcher dm = (InterceptorAndDynamicMethodMatcher)interceptorOrInterceptionAdvice;
Class targetClass = this.targetClass != null ? this.targetClass : this.method.getDeclaringClass();
return dm.methodMatcher.matches(this.method, targetClass, this.arguments) ? dm.interceptor.invoke(this) : this.proceed();
} else {
return ((MethodInterceptor)interceptorOrInterceptionAdvice).invoke(this);//4
}
}
}4、找到AsyncExecutionInterceptor执行器
public class AsyncExecutionInterceptor extends AsyncExecutionAspectSupport implements MethodInterceptor, Ordered {
@Nullable
public Object invoke(MethodInvocation invocation) throws Throwable {
return this.doSubmit(task, executor, invocation.getMethod().getReturnType());//4
}
public class ThreadPoolTaskExecutor extends ExecutorConfigurationSupport implements AsyncListenableTaskExecutor, SchedulingTaskExecutor {
public Future submit(Callable task) { //5
ThreadPoolExecutor executor = this.getThreadPoolExecutor();
try {
return executor.submit(task);
} catch (RejectedExecutionException var4) {
throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, var4);
}
}
} 4、通过doSubmit将任务发给TaskExecutor，实现Async异步的功能。
5、ThreadPoolTaskExecutor就是在demo中定义的WorkPool。
最终实现Asyn异步调用。