項目目錄結構
項目下載
https://github.com/cbeann/Demoo/tree/master/async-demo
實踐
pom
<!-- https://mvnrepository.com/artifact/cglib/cglib -->
<!--cglib依賴-->
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>2.2.2</version>
</dependency>
自定義標註註解
沒有方法參數的註解成爲標註註解
//Async註解
@Target(ElementType.METHOD)//方法註解
@Retention(RetentionPolicy.RUNTIME)//運行時註解
public @interface MyAsyncInterface {
}
自定義執行器
package com.imooc.demo.executor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
import java.util.concurrent.FutureTask;
public class MyExecutor {
/*
動態代理的異步執行方法,參數就是 invoke(Object proxy, Method method, Object[] args)
*/
public static void submit(Object object, Method method, Object[] args) throws Exception {
//封裝成callable接口
MyDyCallable myCallable = new MyDyCallable(object, method, args);
FutureTask futureTask = new FutureTask(myCallable);
//運行線程
new Thread(futureTask).start();
}
/*
cglib的異步執行方法intercept(Object object, Method method, Object[] args, MethodProxy proxy)
*/
public static void submit(Object object, Method method, Object[] args, MethodProxy proxy) throws Exception {
//封裝成callable接口
MyCglibCallable myCglibCallable = new MyCglibCallable(object, method, args, proxy);
FutureTask futureTask = new FutureTask(myCglibCallable);
//運行線程
new Thread(futureTask).start();
}
}
實現動態代理的異步執行
IEmailService接口
public interface IEmailService {
public void sendEmail();
public void speak();
}
IEmailService接口實現類
其中帶有MyAsyncInterface我們要使其成爲異步方法
package com.imooc.demo.dyproxy;
import com.imooc.demo.myinterface.MyAsyncInterface;
public class EmailService implements IEmailService {
@MyAsyncInterface
@Override
public void sendEmail() {
System.out.println("開始發送email---------->睡10秒");
try {
//處理業務10毫秒
Thread.sleep(1000 * 2);
} catch (Exception e) {
}
System.out.println("結束髮發送email<----------");
}
public void speak() {
System.out.println("-----EmailService------");
}
}
MyAsyncHandler (動態代理知識)
package com.imooc.demo.dyproxy;
import com.imooc.demo.myinterface.MyAsyncInterface;
import com.imooc.demo.executor.MyExecutor;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
public class MyAsyncHandler implements InvocationHandler {
//目標對象
private Object target;
//傳入代碼目標對象
public MyAsyncHandler(Object object) {
this.target = object;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable, Exception {
//method參數是接口的方法,上面是不帶@MyAsyncInterface的,我們一般是定義在接口實現類上,所以我們通過接口的method獲取target(實現類)的方法,從而獲取自定義註解信息
MyAsyncInterface annotation = target.getClass().getMethod(method.getName(), method.getParameterTypes()).getAnnotation(MyAsyncInterface.class);
if (null != annotation) {
//如果該方法有自定義異步註解,啓動線程跑
MyExecutor.submit(target, method, args);
} else {
//如果該方法沒有自定義異步註解,同步執行
Object invoke = method.invoke(target, args);
}
//如果有結果返回,如果沒有就不返回
return null;
}
}
MyDyCallable:實現Callable接口(多線程知識)
目的:如果方法時異步,將參數傳入callable,並且啓動線程執行
package com.imooc.demo.executor;
import java.lang.reflect.Method;
import java.util.concurrent.Callable;
public class MyDyCallable implements Callable<Object> {
private Object target;
private Method method;
private Object[] args;
public MyDyCallable(Object object, Method method, Object[] args) {
this.target = object;
this.method = method;
this.args = args;
}
@Override
public Object call() throws Exception {
Object result = method.invoke(target, args);
return result;
}
}
ProxyStart:測試類
package com.imooc.app;
import com.imooc.demo.dyproxy.EmailService;
import com.imooc.demo.dyproxy.IEmailService;
import com.imooc.demo.dyproxy.MyAsyncHandler;
import java.lang.reflect.Proxy;
public class ProxyStart {
public static void main(String[] args) {
IEmailService emailService = new EmailService();
MyAsyncHandler asyncHandler = new MyAsyncHandler(emailService);
Class cls = emailService.getClass();
//創建動態代理對象
IEmailService newProxyInstance = (IEmailService) Proxy.newProxyInstance(
cls.getClassLoader(), cls.getInterfaces(), asyncHandler);
//此方法時異步
newProxyInstance.sendEmail();
//此方法時同步
newProxyInstance.speak();
// 執行結果如下:
// -----EmailService------ newProxyInstance.speak()方法
// 開始發送email---------->睡10秒 newProxyInstance.sendEmail();方法
// 結束髮發送email<----------
}
}
實現cglib的異步執行
MQService
方法setMessage方法,我們使其成爲異步方法
package com.imooc.demo.cglibproxy;
import com.imooc.demo.myinterface.MyAsyncInterface;
public class MQService {
@MyAsyncInterface
public void setMessage(String messgae) {
System.out.println("開始發送MQmessage--------->睡3秒");
try {
Thread.sleep(1000 * 3);
} catch (Exception e) {
}
System.out.println("結束髮送MQmessage<-------------");
}
}
CGlibProxy (動態代理cglib知識)
package com.imooc.demo.cglibproxy;
import com.imooc.demo.executor.MyExecutor;
import com.imooc.demo.myinterface.MyAsyncInterface;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
public class CGlibProxy implements MethodInterceptor {
private Enhancer enhancer = new Enhancer();
public Object getProxy(Class clz) {
enhancer.setSuperclass(clz);
enhancer.setCallback(this);
return enhancer.create();
}
/**
* @param object 目標類的實例
* @param method 目標方法的反射對象
* @param args 目標方法的參數
* @param proxy 代理類的實例
* @return
* @throws Throwable
*/
@Override
public Object intercept(Object object, Method method, Object[] args, MethodProxy proxy) throws Throwable {
if (method.getAnnotation(MyAsyncInterface.class) != null) {
MyExecutor.submit(object, method, args, proxy);
} else {
proxy.invokeSuper(object, args);
}
return null;
}
}
MyCglibCallable (多線程知識)
package com.imooc.demo.executor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
import java.util.concurrent.Callable;
public class MyCglibCallable implements Callable {
private Object object;
private Method method;
private Object[] args;
private MethodProxy proxy;
//參數是intercept(Object object, Method method, Object[] args, MethodProxy proxy)
public MyCglibCallable(Object object, Method method, Object[] args, MethodProxy proxy) {
this.object = object;
this.args = args;
this.method = method;
this.proxy = proxy;
}
@Override
public Object call() {
try {
proxy.invokeSuper(object, args);
} catch (Throwable throwable) {
throwable.printStackTrace();
}
return null;
}
}
CGlibStart 測試類
package com.imooc.app;
import com.imooc.demo.cglibproxy.CGlibProxy;
import com.imooc.demo.cglibproxy.MQService;
public class CGlibStart {
public static void main(String[] args) {
// MQService mqService = new MQService();
// mqService.setMessage("123123");
CGlibProxy cGlibProxy = new CGlibProxy();
MQService proxy = (MQService) cGlibProxy.getProxy(MQService.class);
proxy.setMessage("123");
System.out.println("-----------------------");
// 執行結果
// ----------------------- System.out.println("-----------------------");
// 開始發送MQmessage--------->睡3秒 proxy.setMessage("123");
// 結束髮送MQmessage<-------------
}
}
總結
1)需要了解動態代理、多線程知識
2)上面都是按照方法沒有返回結果算的,實際情況下是很多是有結果的
3)多線程中Callable是有返回結果的