= code cleanup

- for loop replaceable with enhanced 'for' loop
  - using diamond in generic type
  - collapse try catch exception
  - using try-with-resource
  - using  List#sort instead of Collections#sort
  - replaced lambda with method reference
  - using native compare method to compare numbers
  - using switch instead of if for in ESSyncUtil

meta/src/main/java/com/alibaba/otter/canal/meta/ZooKeeperMetaManager.java

@@ -191,7 +191,7 @@ public class ZooKeeperMetaManager extends AbstractCanalLifeCycle implements Cana
         }
 
         // 找到最小的Id
-        ArrayList<Long> batchIds = new ArrayList<Long>(nodes.size());
+        ArrayList<Long> batchIds = new ArrayList<>(nodes.size());
         for (String batchIdString : nodes) {
             batchIds.add(Long.valueOf(batchIdString));
         }