无法从Play框架2.4中的cron作业加载application.conf

Question

I have created a cron job that start during application restart but when i tried to create db connection i am geeting null pointer exception. I am able to create and use db from other module using same configuration.

Below is my Application.conf

db.abc.driver=com.mysql.jdbc.Driver
db.abc.url="jdbc:mysql://localhost:3306/db_name?useSSL=false"
db.abc.username=root
db.abc.password=""
db.abc.autocommit=false
db.abc.isolation=READ_COMMITTED

And code that tried to access db is

public class SchduleJob extends AbstractModule{
    @Override
    protected void configure() {
        bind(JobOne.class)
        .to(JobOneImpl.class)
        .asEagerSingleton();
    }    }

@ImplementedBy(JobOneImpl.class)
public interface JobOne {}

@Singleton
public class JobOneImpl implements JobOne {
    final ActorSystem actorSystem = ActorSystem.create("name");
    final ActorRef alertActor = actorSystem.actorOf(AlertActor.props);

    public JobOneImpl() {
        scheduleJobs();
    }

    private Cancellable scheduleJobs() {
        return actorSystem.scheduler().schedule(
                Duration.create(0, TimeUnit.MILLISECONDS), //Initial delay 0 milliseconds
                Duration.create(6, TimeUnit.MINUTES),     //Frequency 30 minutes
                alertActor,
                "alert",
                actorSystem.dispatcher(),
                null
                );
    }
}

public class AlertActor  extends UntypedActor{

public static Props props = Props.create(AlertActor.class);
final ActorSystem actorSystem = ActorSystem.create("name");
final ActorRef messageActor = actorSystem.actorOf(MessageActor.props());

@Override
public void onReceive(Object message) throws Exception {
    if(message != null && message instanceof String) {
        RequestDAO requestDAO = new RequestDAO();
        try {
            List<DBRow> rows = requestDAO.getAllRow();  
        } catch(Exception exception) {
            exception.printStackTrace();
        }
    }
}

}

public class RequestDAO {
public List<DBRow> getAllRow() throws Exception {
        List<DBRow> rows = new ArrayList<DBRow>();
        Connection connection = null;    
        try {
            connection = DB.getDataSource("abc").getConnection();
            connection.setAutoCommit(false);
} catch(Exception exception) {
            exception.printStackTrace();
            if(connection != null) {
                connection.rollback();
            } else {
                System.out.println("in else***********");
            }
            return null;
        } finally {
            if(connection != null)
                connection.close();
        }
        return schools; 
    }

When i am calling method getAllRow() of RequestDAO class it's throwing

java.lang.NullPointerException
    at play.api.Application$$anonfun$instanceCache$1.apply(Application.scala:235)
    at play.api.Application$$anonfun$instanceCache$1.apply(Application.scala:235)
    at play.utils.InlineCache.fresh(InlineCache.scala:69)
    at play.utils.InlineCache.apply(InlineCache.scala:55)
    at play.api.db.DB$.db(DB.scala:22)
    at play.api.db.DB$.getDataSource(DB.scala:41)
    at play.api.db.DB.getDataSource(DB.scala)
    at play.db.DB.getDataSource(DB.java:33)

But same code is working without cron job. What should i do to remove this error

Answer 1

Play uses the Typesafe config library for configuration.

I suspect your current working directory from the cron script isn't set, so it's probably not finding your application.conf ( application.properties ) file.

However, Config is nice in that it allows you to specify where to look for the file, either by its base name (to choose among .conf | .properties | .json extensions) or the filename including the extension on the java command line:

• To specify the base name, use -Dconfig.resource=/path/to/application
• To specify the full name, use -Dconfig.file=/path/to/application.properties