在java中运行异步作业时实现优雅取消的最佳方法
假设我有一个这样的接口，可以让应用程序中的组件运行作业-在java中运行异步作业时实现优雅取消的最佳方法,java,java.util.concurrent,Java,Java.util.concurrent,假设我有一个这样的接口，可以让应用程序中的组件运行作业- IJob { IResult execute(); void cancel(); } 我想设置我的应用程序，以便异步运行这些作业。我们期望调用cancel会立即返回execute，结果表明它已被取消 最好的设置方法是什么？我可以创建一个Thread对象来运行它，它有额外的方法可以取消，但我也在研究我新接触的未来接口 FutureTask的问题是取消不合适，不允许我调用job.cancel（）。扩展FutureTask并实
IJob {
IResult execute();
void cancel();
}
FutureTask的问题是取消不合适，不允许我调用job.cancel（）。扩展FutureTask并实现我自己对它的处理是一个好主意吗？当您在任务中调用
cancelif (Thread.interrupted()) {
performNecessaryCleanup();
return;
}
在任务中调用
cancelif (Thread.interrupted()) {
performNecessaryCleanup();
return;
}
在使用并发时，使用语言提供的内容，而不是手工实现 据我所知，应该是适合您的工具，因为您可以：
- 提供将异步运行并可能返回结果的it作业
- 关闭执行器，以便取消所有正在运行的作业
public static void main(String[] args) {
ExecutorService executor = Executors.newSingleThreadExecutor();
List<Future<IResult>> results = new ArrayList<>();
for (int i = 0; i < 10; i++) {
results.add(executor.submit(new Job(i))); //start jobs
}
executor.shutdownNow(); //attempts to stop all running jobs
//program flow immediatly continues
}
在使用并发时，使用语言提供的内容，而不是手工实现 据我所知，应该是适合您的工具，因为您可以：
- 提供将异步运行并可能返回结果的it作业
- 关闭执行器，以便取消所有正在运行的作业
public static void main(String[] args) {
ExecutorService executor = Executors.newSingleThreadExecutor();
List<Future<IResult>> results = new ArrayList<>();
for (int i = 0; i < 10; i++) {
results.add(executor.submit(new Job(i))); //start jobs
}
executor.shutdownNow(); //attempts to stop all running jobs
//program flow immediatly continues
}
调用IJob.execute（）或FutureTask.run（）将阻止当前线程，您需要调用IJob或FutureTask 安排FutureTask是最好的选择，消费者可以调用FutureTask.get（）并等待结果（即使您调用IJob.cancel（）） 我对IJob和IResult进行了一些演示，它使用普通线程进行调度，在生产中，您应该像前面的帖子示例一样拥有一个执行服务 如您所见，主线程可以检查状态调用FutureTask.isDone（），基本上是检查结果是否已设置。设置结果意味着IJob的线程已完成 如果方法与您的评论中的行为相同，您几乎可以在任何时候调用IJob.cancel（）来完成FutureTask中包装的IJob 模拟作业：
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
调用IJob.execute（）或FutureTask.run（）将阻止当前线程，您需要调用IJob或FutureTask 安排FutureTask是最好的选择，消费者可以调用FutureTask.get（）并等待结果（即使您调用IJob.cancel（）） 我对IJob和IResult进行了一些演示，它使用普通线程进行调度，在生产中，您应该像前面的帖子示例一样拥有一个执行服务 如您所见，主线程可以检查状态调用FutureTask.isDone（），基本上是检查结果是否已设置。设置结果意味着IJob的线程已完成 如果方法与您的评论中的行为相同，您几乎可以在任何时候调用IJob.cancel（）来完成FutureTask中包装的IJob 模拟作业：
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
public class MockJob implements IJob {
private boolean cancelled;
public MockJob() {
}
@Override
public IResult execute() {
int count = 0;
while (!cancelled) {
try {
count++;
System.out.println("Mock Job Thread: count = " + count);
if (count >= 10) {
break;
}
Thread.sleep(1000);
} catch (InterruptedException e) {
cancelled = true;
}
}
return new MockResult(cancelled, count);
}
@Override
public void cancel() {
cancelled = true;
}
}
public class MockResult implements IResult {
private boolean cancelled;
private int result;
public MockResult(boolean cancelled, int result) {
this.cancelled = cancelled;
this.result = result;
}
public boolean isCancelled() {
return cancelled;
}
public int getResult() {
return result;
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
// Job
IJob mockJob = new MockJob();
// Async task
FutureTask<IResult> asyncTask = new FutureTask<>(mockJob::execute);
Thread mockJobThread = new Thread(asyncTask);
// Show result
Thread showResultThread = new Thread(() -> {
try {
IResult result = asyncTask.get();
MockResult mockResult = (MockResult) result;
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: isCancelled = %s, result = %d",
thread.getName(),
mockResult.isCancelled(),
mockResult.getResult()
));
} catch (InterruptedException | ExecutionException ex) {
// NO-OP
}
});
// Check status
Thread monitorThread = new Thread(() -> {
try {
while (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
Thread.sleep(1000);
}
} catch (InterruptedException ex) {
// NO-OP
}
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: asyncTask.isDone = %s",
thread.getName(),
asyncTask.isDone()
));
});
// Async cancel
Thread cancelThread = new Thread(() -> {
try {
// Play with this Thread.sleep, set to 15000
Thread.sleep(5000);
if (!asyncTask.isDone()) {
Thread thread = Thread.currentThread();
System.out.println(String.format("%s: job.cancel()",
thread.getName()
));
mockJob.cancel();
}
} catch (InterruptedException ex) {
// NO-OP
}
});
monitorThread.start();
showResultThread.start();
cancelThread.setDaemon(true);
cancelThread.start();
mockJobThread.start();
}
}
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-3: job.cancel()
Thread-2: asyncTask.isDone = false
Thread-1: isCancelled = true, result = 5
Thread-2: asyncTask.isDone = true
Thread-2: asyncTask.isDone = false
Thread-0: count = 1
Thread-2: asyncTask.isDone = false
Thread-0: count = 2
Thread-2: asyncTask.isDone = false
Thread-0: count = 3
Thread-2: asyncTask.isDone = false
Thread-0: count = 4
Thread-2: asyncTask.isDone = false
Thread-0: count = 5
Thread-2: asyncTask.isDone = false
Thread-0: count = 6
Thread-2: asyncTask.isDone = false
Thread-0: count = 7
Thread-2: asyncTask.isDone = false
Thread-0: count = 8
Thread-2: asyncTask.isDone = false
Thread-0: count = 9
Thread-2: asyncTask.isDone = false
Thread-0: count = 10
Thread-1: isCancelled = false, result = 10
Thread-2: asyncTask.isDone = true
未来的“不优雅”是怎么回事？多线程是很难的，试图改变未来的实现很可能会引入bug。确定“不优雅”可能不是最好的选择。我的意思是cancel（）发送了一个线程中断，但实际上并没有给我时间来正确调用job.cancel（）。如果我创建了一个调用job.execute（）的FutureTask（阻塞调用），那么我将如何处理取消请求以便调用job.cancel（）？什么？对不起，我一点也不明白。您必须向我们展示一些代码，解释为什么您没有时间做某事。（为了响应您的编辑：have
execute（）InterruptedExceptionexecuterservice