diff --git a/lib/generator.dart b/lib/generator.dart
index 2fc616c..9c1ad55 100644
--- a/lib/generator.dart
+++ b/lib/generator.dart
@@ -4,17 +4,15 @@ import 'package:json2dart_serialization/template.dart';
 
 class Generator {
   String jsonString;
-  String fileName;
   String entityName;
 
-  Generator(this.jsonString, this.fileName, [this.entityName]);
+  Generator(this.jsonString, [this.entityName]);
 
   List<DefaultTemplate> templateList = [];
 
   String makeDartCode() {
     var entityName = this.entityName ?? "Entity";
-    DefaultTemplate template =
-        DefaultTemplate(srcJson: jsonString, className: entityName);
+    DefaultTemplate template = DefaultTemplate(srcJson: jsonString, className: entityName);
     StringBuffer resultSb = StringBuffer();
     templateList.add(template);
     refreshTemplate(template);
@@ -32,14 +30,12 @@ class Generator {
     fieldList.forEach((filed) {
       if (filed is MapField) {
 //        filed.typeString
-        DefaultTemplate template = DefaultTemplate(
-            srcJson: json.encode(filed.map), className: filed.typeString);
+        DefaultTemplate template = DefaultTemplate(srcJson: json.encode(filed.map), className: filed.typeString);
         templateList.add(template);
         refreshTemplate(template);
       } else if (filed is ListField) {
         if (filed.childIsObject) {
-          DefaultTemplate template = DefaultTemplate(
-              srcJson: json.encode(filed.list[0]), className: filed.typeName);
+          DefaultTemplate template = DefaultTemplate(srcJson: json.encode(filed.list[0]), className: filed.typeName);
           templateList.add(template);
           refreshTemplate(template);
         }
@@ -47,12 +43,21 @@ class Generator {
     });
   }
 
-  static const String importString =
-      "import 'package:json_annotation/json_annotation.dart';";
+  String get fileName => camelCase2UnderScoreCase(entityName);
+
+  static const String importString = "import 'package:json_annotation/json_annotation.dart';";
 
   String get header => """$importString 
   
-part $fileName.g.dart;
+part '$fileName.g.dart';
 
 """;
 }
+
+String camelCase2UnderScoreCase(String name) {
+  return name[0].toLowerCase() +
+      name.substring(1).replaceAllMapped(RegExp("[A-Z]"), (match) {
+        var str = match.group(0);
+        return "_" + str.toLowerCase();
+      });
+}
diff --git a/lib/json_generator.dart b/lib/json_generator.dart
index 36ccfba..3950d47 100644
--- a/lib/json_generator.dart
+++ b/lib/json_generator.dart
@@ -75,6 +75,14 @@ void main() {
   });
 
   refreshData();
+
+  querySelector("#copy").onClick.listen((event) {
+    TextAreaElement result = querySelector("#result");
+    result.focus();
+    result.setSelectionRange(0, result.textLength);
+    document.execCommand("copy", null, "");
+    result.blur();
+  });
 }
 
 void refreshData() {
@@ -95,8 +103,10 @@ void refreshData() {
     entityClassName = entityName;
   }
 
-  var generator = Generator(string, 'test.dart', entityClassName);
+  var generator = Generator(string, entityClassName);
   var dartCode = generator.makeDartCode();
+  var dartFileName = ("${generator.fileName}.dart");
+  querySelector("#file_name").text = "应该使用的文件名为: $dartFileName";
 
   result.value = dartCode;
 }
diff --git a/lib/template.dart b/lib/template.dart
index 8549bd1..fddc430 100644
--- a/lib/template.dart
+++ b/lib/template.dart
@@ -60,7 +60,7 @@ class $className extends Object with _\$${className}SerializerMixin {""";
       }
       String nameString;
       if (main.isCamelCase) {
-        nameString = camelCase(f.nameString);
+        nameString = firstLetterLower(camelCase(f.nameString));
       } else {
         nameString = f.nameString;
       }
diff --git a/lib/test.dart b/lib/test.dart
index 70610ba..19d38ed 100644
--- a/lib/test.dart
+++ b/lib/test.dart
@@ -1,3 +1,8 @@
-void main() {
-  print(1.0 is int);
+void main() {}
+
+String camelCase2UnderScoreCase(String name) {
+  return name.replaceAllMapped(RegExp("[A-Z]"), (match) {
+    var str = match.group(0);
+    return "_" + str.toLowerCase();
+  });
 }
diff --git a/web/index.html b/web/index.html
index d6bba0b..9c471d2 100644
--- a/web/index.html
+++ b/web/index.html
@@ -33,7 +33,9 @@
             <input type="checkbox" id="use_json_key"/><span id="check_label">jsonKey annotation</span>
             <input type="checkbox" id="camelCase"/><span id="camelCaseLabel">use camelCase</span>
         </div>
+        <div id="file_name"></div>
         <textarea id="result" title="结果"></textarea>
+        <div><button id="copy">复制</button></div>
     </div>
 
 </div>
diff --git a/web/styles.css b/web/styles.css
index 2a56106..480fc80 100644
--- a/web/styles.css
+++ b/web/styles.css
@@ -24,13 +24,18 @@ body {
 
 textarea {
     width: 90%;
-    height: 90vh;
+    height: 80vh;
 }
 
 .result_title {
     padding-bottom: 15px;
 }
 
-.out_entity_name{
+#result {
+    width: 90%;
+    height: 70vh;
+}
+
+.out_entity_name {
     height: 40px;
 }
\ No newline at end of file