方法必须是线程安全的？

Question

@PostMapping
public ResponseEntity<?> <name> (<args>) {
<do something>
<do something very time consuming>
<return response>
}

@PostMapping
public ResponseEntity<?> <name> (<args>) {
<do something>

CompletableFuture.runAsync(() -> {
   new <NewClass>.<NewMethod>(<args>);
});

<return response>
}

看起来它工作得很好，但我想知道我是否必须确保新代码需要线程安全？这里有什么意见吗？抱歉用了假名字，提前致谢。

Answer 1

如果您需要对将来的任务进行同步，您可以简单地在将来的相关方法上添加已同步的关键工作，例如：

public class SafeFuture {

    public void doWorkSynced() {
        System.out.println("doing something quick starting");
        CompletableFuture.runAsync(this::doWorkInBackground);
        System.out.println("doing something quick done");
    }

    private synchronized void doWorkInBackground() {
        try {
            System.out.println("doing something slower starting");
            Thread.sleep(1000);
            System.out.println("doing something slower done");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

    public static void main(String[] args) throws Exception {
        SafeFuture safeFuture = new SafeFuture();
        safeFuture.doWorkSynced();
        safeFuture.doWorkSynced();
        Thread.sleep(5000);
    }
}

输出为：

doing something quick starting
doing something quick done
doing something quick starting
doing something quick done
doing something slower starting
doing something slower done
doing something slower starting
doing something slower done

如您所见，不在运行的耗时任务是并行的