diff --git a/src/main/java/com/reandroid/apk/SingleJsonTableInputSource.java b/src/main/java/com/reandroid/apk/SingleJsonTableInputSource.java
index 6ac7a77..1cc1129 100644
--- a/src/main/java/com/reandroid/apk/SingleJsonTableInputSource.java
+++ b/src/main/java/com/reandroid/apk/SingleJsonTableInputSource.java
@@ -1,4 +1,4 @@
- /*
+/*
   *  Copyright (C) 2022 github.com/REAndroid
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -52,22 +52,22 @@ public class SingleJsonTableInputSource extends InputSource {
         return outputStream.getCrcValue();
     }
     public TableBlock getTableBlock() throws IOException{
-        if(mCache!=null){
+        if(mCache != null){
             return mCache;
         }
-        logMessage("Building resources table: "+inputSource.getAlias());
+        logMessage("Building resources table: " + inputSource.getAlias());
         TableBlock tableBlock=newInstance();
-        InputStream inputStream=inputSource.openStream();
+        InputStream inputStream = inputSource.openStream();
         try{
-            StringPoolBuilder poolBuilder=new StringPoolBuilder();
-            JSONObject jsonObject=new JSONObject(inputStream);
+            StringPoolBuilder poolBuilder = new StringPoolBuilder();
+            JSONObject jsonObject = new JSONObject(inputStream);
             poolBuilder.build(jsonObject);
             poolBuilder.apply(tableBlock);
             tableBlock.fromJson(jsonObject);
         }catch (JSONException ex){
-            throw new IOException(inputSource.getAlias()+": "+ex.getMessage());
+            throw new IOException(inputSource.getAlias(), ex);
         }
-        mCache=tableBlock;
+        mCache = tableBlock;
         return tableBlock;
     }
     TableBlock newInstance(){
diff --git a/src/main/java/com/reandroid/apk/StringPoolBuilder.java b/src/main/java/com/reandroid/apk/StringPoolBuilder.java
index 6e7c328..2182582 100644
--- a/src/main/java/com/reandroid/apk/StringPoolBuilder.java
+++ b/src/main/java/com/reandroid/apk/StringPoolBuilder.java
@@ -1,4 +1,4 @@
- /*
+/*
   *  Copyright (C) 2022 github.com/REAndroid
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/src/main/java/com/reandroid/arsc/item/StringItem.java b/src/main/java/com/reandroid/arsc/item/StringItem.java
index 1e6269e..bf3271c 100755
--- a/src/main/java/com/reandroid/arsc/item/StringItem.java
+++ b/src/main/java/com/reandroid/arsc/item/StringItem.java
@@ -254,15 +254,17 @@ public class StringItem extends BlockItem implements JSONConvert<JSONObject> {
         if(isNull()){
             return null;
         }
+        StyleItem styleItem=getStyle();
+        if(styleItem == null){
+            return null;
+        }
         JSONObject jsonObject=new JSONObject();
         jsonObject.put(NAME_string, get());
-        StyleItem styleItem=getStyle();
-        if(styleItem!=null){
-            JSONObject styleJson=styleItem.toJson();
-            if(styleJson!=null){
-                jsonObject.put(NAME_style, styleJson);
-            }
+        JSONObject styleJson = styleItem.toJson();
+        if(styleJson == null){
+            return null;
         }
+        jsonObject.put(NAME_style, styleJson);
         return jsonObject;
     }
     @Override
diff --git a/src/main/java/com/reandroid/arsc/pool/JsonStringPoolHelper.java b/src/main/java/com/reandroid/arsc/pool/JsonStringPoolHelper.java
index da20b00..2f69fbc 100644
--- a/src/main/java/com/reandroid/arsc/pool/JsonStringPoolHelper.java
+++ b/src/main/java/com/reandroid/arsc/pool/JsonStringPoolHelper.java
@@ -1,3 +1,18 @@
+/*
+ *  Copyright (C) 2022 github.com/REAndroid
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.reandroid.arsc.pool;
 
 import com.reandroid.arsc.array.StringArray;
@@ -88,15 +103,21 @@ class JsonStringPoolHelper<T extends StringItem> {
         }
         static List<StyledString> fromJson(JSONArray jsonArray){
             int length = jsonArray.length();
-            List<StyledString> results=new ArrayList<>();
-            for(int i=0;i<length;i++){
-                StyledString styledString=fromJson(jsonArray.getJSONObject(i));
-                results.add(styledString);
+            List<StyledString> results = new ArrayList<>(length);
+            for(int i=0; i < length; i++){
+                StyledString styledString =
+                        fromJson(jsonArray.getJSONObject(i));
+                if(styledString != null){
+                    results.add(styledString);
+                }
             }
             return results;
         }
-        static StyledString fromJson(JSONObject jsonObject){
-            String text= jsonObject.getString(StringItem.NAME_string);
+        private static StyledString fromJson(JSONObject jsonObject){
+            if(!jsonObject.has(StringItem.NAME_style)){
+                return null;
+            }
+            String text = jsonObject.getString(StringItem.NAME_string);
             JSONObject style=jsonObject.getJSONObject(StringItem.NAME_style);
             JSONArray spansArray=style.getJSONArray(StyleItem.NAME_spans);
             List<StyleSpanInfo> spanInfoList = toSpanInfoList(spansArray);
@@ -107,7 +128,7 @@ class JsonStringPoolHelper<T extends StringItem> {
             List<StyleSpanInfo> results=new ArrayList<>(length);
             for(int i=0;i<length;i++){
                 JSONObject jsonObject = jsonArray.getJSONObject(i);
-                StyleSpanInfo spanInfo=new StyleSpanInfo(null, 0,0);
+                StyleSpanInfo spanInfo = new StyleSpanInfo(null, 0,0);
                 spanInfo.fromJson(jsonObject);
                 results.add(spanInfo);
             }