spring boot application does not exit after all tasks are completed

Question

This is my Application class -

@EnableAutoConfiguration
@SpringBootApplication
@Configuration
public class Application implements CommandLineRunner {
private static final Logger log = LoggerFactory.getLogger(Application.class);

@Autowired
private ITestService3 testService3;

public static void main(String[] args) {
    System.exit(SpringApplication.exit(SpringApplication.run(Application.class, args)));

    @Override
    public void run(String... strings) throws Exception {
        testService3.multiThreadTest();
    }
}

Method -

public void multiThreadTest() {
    ThreadPoolExecutor readExecutor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10);
    List<String> files = listFiles(new File("/Users/admin/filesList"), new ArrayList<>());
    for (String file : files) {
        readExecutor.execute(new FileParser(file));
    }
}

Even after all the files are read, the application is not terminated However when i use

System.exit(SpringApplication.exit(SpringApplication.run(Application.class, args)));

Application is terminated and all the threads are killed.

And when i use -

SpringApplication.run(Application.class, args).close();

Threads continue to run even after the application says this -

org.springframework.context.annotation.AnnotationConfigApplicationContext@6eda5c9: startup date [Mon Aug 15 04:42:02 IST 2016]; root of context hierarchy 2016-08-15 04:42:05.390 INFO 36600 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown

And then i have to manually kill the application. And the application exits with code 130

Can someone please help me with a way to gracefully shutdown the application.

Thanks

Answer 1

First off, you are not closing the ExecutorService properly, your multiThreadTest should look like:

public void multiThreadTest() throws InterruptedException {
    ThreadPoolExecutor readExecutor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10);
    List<String> files = listFiles(new File("/Users/admin/filesList"), new ArrayList<>());
    for (String file : files) {
        readExecutor.execute(new FileParser(file));
    }

    readExecutor.shutdown();
    readExecutor.awaitTermination(5, TimeUnit.MINUTES); // wait for tasks to complete
    readExecutor.shutdownNow();
}