java并发学习第二章springboot实现线程的创建

//开启同步线程必须加上注解
@EnableAsync
@SpringBootApplication
public class ThemApplication {
public static void main(String[] args) {
SpringApplication.run(ThemApplication.class, args);
}
}

/**
* 线程池的配置
*
* 需要加上这两个注解
*/
@Configuration
@EnableAsync
public class Pool implements AsyncConfigurer {
@Bean("thread")
public Executor taskExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
// 设置核心线程数
executor.setCorePoolSize(5);
// 设置最大线程数
executor.setMaxPoolSize(10);
// 设置队列容量
executor.setQueueCapacity(20);
// 设置线程活跃时间（秒）
executor.setKeepAliveSeconds(60);
// 设置线程名称
executor.setThreadNamePrefix("hello-");
// 设置拒绝策略
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
// 等待所有任务结束后再关闭线程池
executor.setWaitForTasksToCompleteOnShutdown(true);
return executor;
}
}

@Configuration
public class UseTask {
@Async
public void show(int i) {
System.out.println("线程" +i + " 执行异步任务：" );
}
}

@Configuration
public class UseTask {
//带返回值的线程
@Async
public Future showSum(int i,int j) {
int x=i+j;
System.out.println("当前执行的是第"+i+"线程");
return new AsyncResult(x);
}
}

　　@Test
public void thread() throws ExecutionException, InterruptedException {
int j = 0;
for (int i = 0; i <10; i++) {
//返回的类型
Future num = useTask.showSum(i, i);
//get方法获取返回值
j = num.get();
System.out.println("计算结果是" + j);
}
}

/**
* 监控线程的类很简单，只需要继承ThreadPoolTaskExecutor
*
*/
@Configuration
public class Monitor extends ThreadPoolTaskExecutor {
/**
* 创建一个线程安全的ConcurrentHashMap，存储监控的信息
*/
public ConcurrentHashMap threadPoolMap = new ConcurrentHashMap<>();
}

/**
* 线程池的配置
*
* 需要加上这两个注解
*/
@Configuration
@EnableAsync
public class Pool implements AsyncConfigurer {
@Autowired
Monitor monitor;
@Bean("thread")
public Executor taskExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
// 设置核心线程数
executor.setCorePoolSize(5);
// 设置最大线程数
executor.setMaxPoolSize(10);
// 设置队列容量
executor.setQueueCapacity(20);
// 设置线程活跃时间（秒）
executor.setKeepAliveSeconds(60);
// 设置线程名称
executor.setThreadNamePrefix("hello-");
// 设置拒绝策略
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
// 等待所有任务结束后再关闭线程池
executor.setWaitForTasksToCompleteOnShutdown(true);
//配置线程池到线程监控类中，第一个参数为线程池的名称
monitor.threadPoolMap.put("thread", executor);
return executor;
}
}

@RestController
public class Test {
@Autowired
UseTask useTask;
@Autowired
Monitor monitor;
@RequestMapping(value="/test",method= RequestMethod.GET)
public void meetInitMain() throws InterruptedException {
　　　　//线程任务的创建
useTask.show(1);
useTask.show(2);
useTask.show(3);
useTask.show(4);
useTask.show(5);
//获取监控的信息,从threadPoolMap中得到在线程池配置类中put进去的线程池名称
ThreadPoolTaskExecutor mOnitorTask= monitor.threadPoolMap.get("thread");
　　　　　//threadPoolExecutor才是线程监控的信息存储类
ThreadPoolExecutor threadPoolExecutor= monitorTask.getThreadPoolExecutor();
//当前线程池中的工作线程数
int poolSize=threadPoolExecutor.getPoolSize();
//队列中的任务
int queueSize=threadPoolExecutor.getQueue().size();
//线程正在执行的任务
int activeCount=threadPoolExecutor.getActiveCount();
//已经执行完成的任务
Long completedTaskCount=threadPoolExecutor.getCompletedTaskCount();
//全部的任务数
Long taskCount=threadPoolExecutor.getTaskCount();
//线程池中曾经最大的线程数量
int largestPoolSize= threadPoolExecutor.getLargestPoolSize();
Thread.sleep(100);
System.out.println("当前线程池中的工作线程数:"+poolSize+" 队列中的任务有："
+queueSize+" 正在执行的任务："+activeCount
+" 已经执行完成的任务:"+completedTaskCount+" 全部的任务数:"+taskCount
+"线程池中曾经最大的线程数量:"+largestPoolSize);
}
}