use dropwizard built-in executor service facilities

src/main/java/com/commafeed/backend/task/ScheduledTask.java

@@ -0,0 +1,32 @@
+package com.commafeed.backend.task;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public abstract class ScheduledTask {
+	protected abstract void run();
+
+	protected abstract long getInitialDelay();
+
+	protected abstract long getPeriod();
+
+	protected abstract TimeUnit getTimeUnit();
+
+	public void register(ScheduledExecutorService executor) {
+		Runnable runnable = new Runnable() {
+			@Override
+			public void run() {
+				try {
+					ScheduledTask.this.run();
+				} catch (Exception e) {
+					log.error(e.getMessage(), e);
+				}
+			}
+		};
+		executor.scheduleWithFixedDelay(runnable, getInitialDelay(), getPeriod(), getTimeUnit());
+	}
+
+}