diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
index 75ea2af9d62..8016f516b45 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
@@ -1216,7 +1216,9 @@ public class DefaultCodegen {
         if (mappedType != null) {
             addImport(m, mappedType);
         }
-    }    /**
+    }
+
+    /**
      * Underscore the given word.
      *
      * @param word The word
@@ -1307,11 +1309,6 @@ public class DefaultCodegen {
     }
 
     public static String camelize(String word, boolean lowercaseFirstLetter) {
-        // throw exception if method name is empty
-        if (StringUtils.isEmpty(word)) {
-            throw new RuntimeException("Empty method name (operationId) not allowed");
-        }
-
         // Replace all slashes with dots (package separator)
         Pattern p = Pattern.compile("\\/(.?)");
         Matcher m = p.matcher(word);
diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java
index f753e63f5f7..f272343a795 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java
@@ -13,6 +13,8 @@ import java.io.File;
 import java.util.Arrays;
 import java.util.HashSet;
 
+import org.apache.commons.lang.StringUtils;
+
 public class JavaClientCodegen extends DefaultCodegen implements CodegenConfig {
     protected String invokerPackage = "io.swagger.client";
     protected String groupId = "io.swagger";
@@ -234,6 +236,11 @@ public class JavaClientCodegen extends DefaultCodegen implements CodegenConfig {
 
     @Override
     public String toOperationId(String operationId) {
+        // throw exception if method name is empty
+        if (StringUtils.isEmpty(operationId)) {
+            throw new RuntimeException("Empty method name (operationId) not allowed");
+        }
+
         // method name cannot use reserved keyword, e.g. return
         if (reservedWords.contains(operationId)) {
             throw new RuntimeException(operationId + " (reserved word) cannot be used as method name");