Implement Scheduler component for cron jobs

Author: obasekiosa

src/main/java/org/commonwl/view/Scheduler.java

@@ -1,26 +1,58 @@
-package org.commonwl.view.workflow;
+package org.commonwl.view;
 
 
+import org.commonwl.view.workflow.QueuedWorkflowRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Component;
 
+import java.util.Calendar;
 import java.util.Date;
 
+/**
+ * Scheduler class for recurrent processes.
+ */
 @Component
 public class Scheduler {
 
+    private final Logger logger = LoggerFactory.getLogger(this.getClass());
     private final QueuedWorkflowRepository queuedWorkflowRepository;
 
+    @Value("${queuedWorkflowAgeLimitHours}")
+    private Integer QUEUED_WORKFLOW_AGE_LIMIT_HOURS;
+
     @Autowired
     public Scheduler(QueuedWorkflowRepository queuedWorkflowRepository) {
         this.queuedWorkflowRepository = queuedWorkflowRepository;
     }
 
-    @Scheduled(cron = "* * * * * ?")
+
+    /**
+     * A Scheduled function to delete old queued workflow entries
+     * from the queue. Age is determined by DELETE_INTERVAL_HOUR
+     */
+    @Scheduled(cron = "${cron.deleteOldQueuedWorkflows}")
     public void removeOldQueuedWorkflowEntries() {
+        Calendar calendar = Calendar.getInstance();
         Date now = new Date();
-        System.out.println("The time is " + now);
-        System.out.println("The repository is " + queuedWorkflowRepository.toString());
+        calendar.setTime(now);
+
+        if (QUEUED_WORKFLOW_AGE_LIMIT_HOURS == null) {
+            QUEUED_WORKFLOW_AGE_LIMIT_HOURS = 24;
+        }
+
+        // calculate time QUEUED_WORKFLOW_AGE_LIMIT_HOURS before now
+        calendar.add(Calendar.HOUR, -QUEUED_WORKFLOW_AGE_LIMIT_HOURS);
+        Date removeTime = calendar.getTime();
+
+        logger.info("The time is " + now);
+        logger.info("Delete time interval is : OLDER THAN " + QUEUED_WORKFLOW_AGE_LIMIT_HOURS + " HOURS");
+        logger.info("Deleting queued workflows older than or equal to " + removeTime);
+
+        logger.info(queuedWorkflowRepository.deleteByTempRepresentation_RetrievedOnLessThanEqual(removeTime)
+                + " Old queued workflows removed");
     }
 }