一、多线程
Springt通过任务执行器（TaskExecutor）来实现多线程和并发编程。使用ThreadPoolTaskExecutor可实现一个基于线程池的TaskExecutor。而实际开发中任务一般是非阻碍的，即异步的，所以我们要在配置类中通过@EnableAsync 开启对异步任务的支持，并通过实际执行Bean的方法中使用@Async注解来声明其是一个异步任务。
示例：
1.配置类。
package com.ecworking.async; import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.AsyncConfigurer;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor; import java.util.concurrent.Executor; @Configuration
@ComponentScan("com.ecworking.async")
@EnableAsync // 利用@EnableAsync注解开启异步任务支持
public class AsyncTaskConfig implements AsyncConfigurer{
@Override
public Executor getAsyncExecutor() { // 配置类实现AsyncConfigurer接口并重写 getAsyncExecutor 方法,并返回一个 ThreadPoolTaskExecutor,这样我们就获得了一个线程池 taskExecutor
ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
taskExecutor.setCorePoolSize(5);
taskExecutor.setMaxPoolSize(10);
taskExecutor.setQueueCapacity(25);
taskExecutor.initialize(); return taskExecutor;
} @Override
public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
return null;
}
}
2.任务执行类
package com.ecworking.async; import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service; @Service
public class AsyncTaskService { @Async // 通过@Async注解表明该方法是一个异步方法，如果注解在类级别，表明该类下所有方法都是异步方法，而这里的方法自动被注入使用ThreadPoolTaskExecutor 作为 TaskExecutor
public void executeAsyncTask(Integer i){
System.out.println("执行异步任务：" + i);
} @Async
public void executeAsyncTaskPlus(Integer i){
System.out.println("执行异步任务+1：" + (i+1));
}
}
3.运行
package com.ecworking.async;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class Mian {
public static void main(String[] args){
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AsyncTaskConfig.class);
AsyncTaskService asyncTaskService = context.getBean(AsyncTaskService.class);
for(int i = 0; i < 10; i++){
asyncTaskService.executeAsyncTask(i);
asyncTaskService.executeAsyncTaskPlus(i);
}
}
}
运行结果是并发执行而不是顺序执行