调用python服务,创建一个线程,提交到线程池。等待返回。如果超时则终止,返回err,并记录日志。
方法二:Future.get(long million, TimeUnit unit) 配合Future.cancle(true)
Future系列(它的子类)的都可以实现,这里采用最简单的Future接口实现。
public class FutureTest { static class Task implements Callable{ public String name; private int time; public Task(String s,int t) { name=s; time=t; } @Override public Boolean call() throws Exception { for(int i=0;i<time;++i){ System.out.println("task "+name+" round "+(i+1)); try { Thread.sleep(1000); } catch (InterruptedException e) { System.out.println(name+" is interrupted when calculating, will stop..."); return false; //注意这里如果不return的话,线程还会继续执行,所以任务超时后在这里处理结果然后返回 } } return true; } }
public static void main(String[] args) { ExecutorService executor=Executors.newCachedThreadPool(); Task task1=new Task("one", 5); Future f1=executor.submit(task1); try { if(f1.get(2, TimeUnit.SECONDS)){ //future将在2秒之后取结果 System.out.println("one complete successfully"); } } catch (InterruptedException e) { System.out.println("future在睡着时被打断"); executor.shutdownNow(); } catch (ExecutionException e) { System.out.println("future在尝试取得任务结果时出错"); executor.shutdownNow(); } catch (TimeoutException e) { System.out.println("future时间超时");
f1.cancel(true); //executor.shutdownNow(); //executor.shutdown(); }finally{
executor.shutdownNow();
} } } ————————————————
ForkJoinPool package com.baeldung.controllers;
import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.http.HttpStatus; import org.springframework.http.ResponseEntity; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.context.request.async.DeferredResult;
import java.util.concurrent.ForkJoinPool;
@RestController public class DeferredResultController {
private final static Logger LOG = LoggerFactory.getLogger(DeferredResultController.class);
@GetMapping("/async-deferredresult")
public DeferredResult<ResponseEntity<?>> handleReqDefResult(Model model) {
LOG.info("Received async-deferredresult request");
DeferredResult<ResponseEntity<?>> output = new DeferredResult<>();
ForkJoinPool.commonPool().submit(() -> {
LOG.info("Processing in separate thread");
try {
Thread.sleep(6000);
} catch (InterruptedException e) {
}
output.setResult(ResponseEntity.ok("ok"));
});
LOG.info("servlet thread freed");
return output;
}
public DeferredResult<ResponseEntity<?>> handleReqWithTimeouts(Model model) {
LOG.info("Received async request with a configured timeout");
DeferredResult<ResponseEntity<?>> deferredResult = new DeferredResult<>(500l);
deferredResult.onTimeout(new Runnable() {
@Override
public void run() {
deferredResult.setErrorResult(
ResponseEntity.status(HttpStatus.REQUEST_TIMEOUT).body("Request timeout occurred."));
}
});
ForkJoinPool.commonPool().submit(() -> {
LOG.info("Processing in separate thread");
try {
Thread.sleep(600l);
deferredResult.setResult(ResponseEntity.ok("ok"));
} catch (InterruptedException e) {
LOG.info("Request processing interrupted");
deferredResult.setErrorResult(ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
.body("INTERNAL_SERVER_ERROR occurred."));
}
});
LOG.info("servlet thread freed");
return deferredResult;
}
public DeferredResult<ResponseEntity<?>> handleAsyncFailedRequest(Model model) {
DeferredResult<ResponseEntity<?>> deferredResult = new DeferredResult<>();
ForkJoinPool.commonPool().submit(() -> {
try {
// Exception occurred in processing
throw new Exception();
} catch (Exception e) {
LOG.info("Request processing failed");
deferredResult.setErrorResult(ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
.body("INTERNAL_SERVER_ERROR occurred."));
}
});
return deferredResult;
}
}