Java 启动以前关闭的ExecutionService时获取RejectedExecutionException
我试图实现生产者-消费者模式,我希望能够阻止消费者。到目前为止,我写道:Java 启动以前关闭的ExecutionService时获取RejectedExecutionException,java,multithreading,Java,Multithreading,我试图实现生产者-消费者模式,我希望能够阻止消费者。到目前为止,我写道: import java.util.concurrent.BlockingQueue; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.LinkedBlockingQueue; public class Test { public stat
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
public class Test {
public static void main(final String[] args) throws InterruptedException {
final BlockingQueue<String> messages = new LinkedBlockingQueue<>(100);
final ExecutorService producer = Executors.newSingleThreadExecutor();
final Consumer consumer = new Consumer(messages);
producer.execute(new Runnable() {
@Override
public void run() {
for (int i = 0;; i++) {
try {
messages.put("Message " + i);
Thread.sleep(500);
} catch (final InterruptedException e) {
Thread.currentThread().interrupt();
}
}
}
});
consumer.start();
consumer.stop();
consumer.start();
}
private static class Consumer {
private final ExecutorService consumer = Executors.newSingleThreadExecutor();
private final BlockingQueue<String> messages;
public Consumer(final BlockingQueue<String> m) {
messages = m;
}
public void start() {
consumer.execute(new Runnable() {
@Override
public void run() {
while (!Thread.currentThread().isInterrupted()) {
try {
System.out.println(messages.take());
} catch (final InterruptedException e) {
Thread.currentThread().interrupt();
break;
}
}
}
});
}
public void stop() {
consumer.shutdownNow();
}
}
}
为什么我不能“重启”执行人,或者我如何才能做到这一点
提前谢谢 这是因为当您的类
Consumer
尝试Consumer.execute(new Runnable(){
)时,它的执行器已经关闭。为什么?因为在第行Consumer.start();
之后,您的程序立即终止:您不必等待任务执行
您应该这样修改您的代码:
submit
方法,而不是execute
:producer.submit(新的Runnable(){…}
execute()
方法Future
对象接收:
Future f=producer.submit(新的Runnable(){…}
consumer.start();
f.get();
更新根据相关的更新代码,我们应该讨论这两个新的行:
consumer.start();
consumer.stop();
consumer.start();
您应该知道,在您的执行器停止一次之后,您将无法在其中执行新任务。因此,这就解释了为什么您在最后一行consumer.start();
中收到此异常
启动有序关机,在该关机过程中,以前提交的任务将被删除
已执行,但不会接受新任务
因此,在修改JDK代码之前,无法重新启动。对不起,我忘记了这一行后面的两行。我已经对问题进行了更新。我在第一次启动调用之后调用stop和start。
consumer.start();
consumer.stop();
consumer.start();