add spotless plugin
diff --git a/service_discovery/interface/java-client/src/main/java/org/apache/dubbo/samples/Main.java b/service_discovery/interface/java-client/src/main/java/org/apache/dubbo/samples/Main.java
index 6cbdb9e..8609f1b 100644
--- a/service_discovery/interface/java-client/src/main/java/org/apache/dubbo/samples/Main.java
+++ b/service_discovery/interface/java-client/src/main/java/org/apache/dubbo/samples/Main.java
@@ -17,13 +17,13 @@
 
 package org.apache.dubbo.samples;
 
+import java.io.IOException;
+
 import org.apache.dubbo.samples.proto.GreetRequest;
 import org.apache.dubbo.samples.proto.GreetResponse;
 import org.apache.dubbo.samples.proto.GreetService;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 
-import java.io.IOException;
-
 public class Main {
 
     public static void main(String[] args) throws InterruptedException, IOException {
diff --git a/service_discovery/service/java-client/src/main/java/org/apache/dubbo/samples/Main.java b/service_discovery/service/java-client/src/main/java/org/apache/dubbo/samples/Main.java
index 0e0ea74..73c281c 100644
--- a/service_discovery/service/java-client/src/main/java/org/apache/dubbo/samples/Main.java
+++ b/service_discovery/service/java-client/src/main/java/org/apache/dubbo/samples/Main.java
@@ -17,13 +17,13 @@
 
 package org.apache.dubbo.samples;
 
+import java.io.IOException;
+
 import org.apache.dubbo.samples.proto.GreetRequest;
 import org.apache.dubbo.samples.proto.GreetResponse;
 import org.apache.dubbo.samples.proto.GreetService;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 
-import java.io.IOException;
-
 public class Main {
 
     public static void main(String[] args) throws InterruptedException, IOException {