详解Spring Boot如何使用多线程

@Configuration
@EnableAsync
public class AsyncConfiguration {

 @Bean("doSomethingExecutor")
 public Executor doSomethingExecutor() {
  ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
  // 核心线程数：线程池创建时候初始化的线程数
  executor.setCorePoolSize(10);
  // 最大线程数：线程池最大的线程数，只有在缓冲队列满了之后才会申请超过核心线程数的线程
  executor.setMaxPoolSize(20);
  // 缓冲队列：用来缓冲执行任务的队列
  executor.setQueueCapacity(500);
  // 允许线程的空闲时间60秒：当超过了核心线程之外的线程在空闲时间到达之后会被销毁
  executor.setKeepAliveSeconds(60);
  // 线程池名的前缀：设置好了之后可以方便我们定位处理任务所在的线程池
  executor.setThreadNamePrefix("do-something-");
  // 缓冲队列满了之后的拒绝策略：由调用线程处理（一般是主线程）
  executor.setRejectedExecutionHandler(new ThreadPoolExecutor.DiscardPolicy());
  executor.initialize();
  return executor;
 }
}

@RestController
public class AsyncController {

 @Autowired
 private AsyncService asyncService;

 @GetMapping("/open/something")
 public String something() {
  int count = 10;
  for (int i = 0; i < count; i++) {
   asyncService.doSomething("index = " + i);
  }
  return "success";
 }
}


@Slf4j
@Service
public class AsyncService {

 // 指定使用beanname为doSomethingExecutor的线程池
 @Async("doSomethingExecutor")
 public String doSomething(String message) {
  log.info("do something, message={}", message);
  try {
   Thread.sleep(1000);
  } catch (InterruptedException e) {
   log.error("do something error: ", e);
  }
  return message;
 }
}

@RestController
public class AsyncController {

 @Autowired
 private AsyncService asyncService;

 @SneakyThrows
 @ApiOperation("异步 有返回值")
 @GetMapping("/open/somethings")
 public String somethings() {
  CompletableFuture<String> createOrder = asyncService.doSomething1("create order");
  CompletableFuture<String> reduceAccount = asyncService.doSomething2("reduce account");
  CompletableFuture<String> saveLog = asyncService.doSomething3("save log");
  
  // 等待所有任务都执行完
  CompletableFuture.allOf(createOrder, reduceAccount, saveLog).join();
  // 获取每个任务的返回结果
  String result = createOrder.get() + reduceAccount.get() + saveLog.get();
  return result;
 }
}


@Slf4j
@Service
public class AsyncService {

 @Async("doSomethingExecutor")
 public CompletableFuture<String> doSomething1(String message) throws InterruptedException {
  log.info("do something1: {}", message);
  Thread.sleep(1000);
  return CompletableFuture.completedFuture("do something1: " + message);
 }

 @Async("doSomethingExecutor")
 public CompletableFuture<String> doSomething2(String message) throws InterruptedException {
  log.info("do something2: {}", message);
  Thread.sleep(1000);
  return CompletableFuture.completedFuture("; do something2: " + message);
 }

 @Async("doSomethingExecutor")
 public CompletableFuture<String> doSomething3(String message) throws InterruptedException {
  log.info("do something3: {}", message);
  Thread.sleep(1000);
  return CompletableFuture.completedFuture("; do something3: " + message);
 }
}

C:\Users\Administrator>curl -X GET "http://localhost:8200/open/somethings" -H "accept: */*"
do something1: create order; do something2: reduce account; do something3: save log