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Merge pull request #9996 from sahilsingla112/feature/BAEL-4558-stopexecution

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BAEL-4558: Article for stopping execution after a certain time
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davidmartinezbarua 2020-10-24 11:20:19 -03:00 committed by GitHub
commit e459c3faa0
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core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/stopexecution/StopExecution.java Normal file
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package com.baeldung.concurrent.stopexecution;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
public class StopExecution {
private static final Logger LOG = LoggerFactory.getLogger(StopExecution.class);
public static void main(String[] args) {
StopExecution stopExecution = new StopExecution();
//stopExecution.testUsingLoop();
//stopExecution.testTimer();
stopExecution.testScheduledExecutor();
LOG.info("done");
}
public void testUsingLoop() {
long start = System.currentTimeMillis();
long end = start + 5000;
List<String> items = new ArrayList<>();
int counter = 0;
// Let this loop run only upto 5 seconds
while (System.currentTimeMillis() < end && counter < items.size()) {
// Fetch the item from the list.
// Some expensive operation on the item.
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
counter++;
}
}
public static void testThreads() {
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
LOG.info("inside run");
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
LOG.info("exit run");
}
});
thread.start();
while (thread.getState() != Thread.State.TERMINATED) {
LOG.info(thread.getState().name());
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public static void testExecutor() {
final ExecutorService service = Executors.newSingleThreadExecutor();
Future<String> f = null;
try {
f = service.submit(() -> {
// Do you long running calculation here
try {
Thread.sleep(2737); // Simulate some delay
} catch (InterruptedException e) {
LOG.info("Interrupted");
return "interrupted";
}
LOG.info("Sleep finished");
return "42";
});
LOG.info(f.get(2, TimeUnit.SECONDS));
} catch (TimeoutException e) {
f.cancel(true);
LOG.error("Calculation took to long");
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
service.shutdown();
}
}
public void testExecutor2() {
final ExecutorService service = Executors.newSingleThreadExecutor();
Future f = null;
try {
f = service.submit(new LongRunningTask());
LOG.info("testExecutor2");
f.get(1, TimeUnit.SECONDS);
} catch (final TimeoutException e) {
f.cancel(true);
LOG.error("Calculation took to long");
} catch (final Exception e) {
throw new RuntimeException(e);
} finally {
service.shutdownNow();
}
}
public void testScheduledExecutor() {
LOG.info("testScheduledExecutor");
ScheduledExecutorService executor = Executors.newScheduledThreadPool(2);
Future future = executor.submit(new LongRunningTask());
executor.schedule(new Runnable() {
public void run() {
future.cancel(true);
}
}, 1000, TimeUnit.MILLISECONDS);
executor.shutdown();
}
public void testThreadAndInterrupt() {
Thread t;
try {
t = new Thread(new LongRunningTask());
LOG.info("testExecutor3");
long end = System.currentTimeMillis() + 2000;
t.start();
while (t.isAlive() && System.currentTimeMillis() < end) {
Thread.sleep(50);
}
t.interrupt();
} catch (final Exception e) {
throw new RuntimeException(e);
}
}
public void testTimer() {
LOG.info("Timer test");
Thread t = new Thread(new LongRunningTask());
Timer timeoutTimer = new Timer();
timeoutTimer.schedule(new TimeOutTask(t, timeoutTimer), 1000);
t.start();
}
class MyRunnableTask implements Runnable {
public void run() {
try {
LOG.info("MyRunnable...");
Thread.sleep(10000);
} catch (InterruptedException ie) {
LOG.info("MyRunnable interrupted...");
}
}
}
class TimeOutTask extends TimerTask {
private Thread t;
private Timer timer;
TimeOutTask(Thread t, Timer timer) {
this.t = t;
this.timer = timer;
}
public void run() {
if (t != null && t.isAlive()) {
t.interrupt();
timer.cancel();
}
}
}
class LongRunningTask implements Runnable {
@Override
public void run() {
longRunningSort();
}
private void longRunningOperation() {
LOG.info("long Running operation started");
try {
//Thread.sleep(500);
longFileRead();
LOG.info("long running operation finished");
} catch (InterruptedException e) {
LOG.info("long Running operation interrupted");
}
}
private void longRunningSort() {
LOG.info("long Running task started");
// Do you long running calculation here
int len = 100000;
List<Integer> numbers = new ArrayList<>();
try {
for (int i = len; i > 0; i--) {
//Thread.sleep(5)
numbers.add(i);
}
int i = 0;
for (i = 0; i < len; i++) {
int minIndex = i;
for (int j = i + 1; j < len; j++) {
if (numbers.get(minIndex) > numbers.get(j))
minIndex = j;
}
if (minIndex != i) {
int temp = numbers.get(i);
numbers.set(i, numbers.get(minIndex));
numbers.set(minIndex, temp);
}
throwExceptionOnThreadInterrupt();
}
LOG.info("Index position: " + i);
LOG.info("Long running task finished");
} catch (InterruptedException e) {
LOG.info("long Running operation interrupted");
}
}
private void longFileRead() throws InterruptedException {
String file = "input.txt";
ClassLoader classloader = getClass().getClassLoader();
try (InputStream inputStream = classloader.getResourceAsStream(file)) {
Reader inputStreamReader = new InputStreamReader(inputStream);
int data = inputStreamReader.read();
while (data != -1) {
char theChar = (char) data;
data = inputStreamReader.read();
throwExceptionOnThreadInterrupt();
}
} catch (IOException e) {
LOG.error("Exception: ", e);
}
}
private void throwExceptionOnThreadInterrupt() throws InterruptedException {
if (Thread.currentThread().interrupted()) {
throw new InterruptedException();
}
}
}
}