diff --git a/src/main/java/com/thinker/main/App.java b/src/main/java/com/thinker/main/App.java
index 977d205..168a862 100644
--- a/src/main/java/com/thinker/main/App.java
+++ b/src/main/java/com/thinker/main/App.java
@@ -14,6 +14,11 @@ public class App {
 
     public static final class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {
 
+        /**
+         *
+         */
+        private static final long serialVersionUID = -8040066741965799728L;
+
         @Override
         public void flatMap(String s, Collector<Tuple2<String, Integer>> collector) throws Exception {
             String[] tokens = s.toLowerCase().split("\\W+");
diff --git a/src/main/java/com/thinker/sql/SourceFromMySQL.java b/src/main/java/com/thinker/sql/SourceFromMySQL.java
index 0814b44..c1992de 100644
--- a/src/main/java/com/thinker/sql/SourceFromMySQL.java
+++ b/src/main/java/com/thinker/sql/SourceFromMySQL.java
@@ -18,6 +18,10 @@ import java.sql.ResultSet;
 public class SourceFromMySQL extends RichSourceFunction<Student> {
 
 
+    /**
+     *
+     */
+    private static final long serialVersionUID = 1L;
     private PreparedStatement ps;
     private Connection connection;