diff --git a/pom.xml b/pom.xml
index c1b7e26b5cc16a5db0060b9d2f5906411bf4c090..6b114e35cf606ec8792e25266ccdf57cf6d376cb 100644
--- a/pom.xml
+++ b/pom.xml
@@ -19,6 +19,13 @@
             <artifactId>jackson-databind</artifactId>
             <version>2.9.7</version>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <version>1.7.25</version>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/src/main/java/JsonFileCompare.java b/src/main/java/JsonFileCompare.java
index 9cd4440826ab5d03c90c95b21acf431e7f5b0598..fd85c1fa1e7b489b775d52a77cc63770e27676f3 100644
--- a/src/main/java/JsonFileCompare.java
+++ b/src/main/java/JsonFileCompare.java
@@ -1,7 +1,8 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -11,10 +12,9 @@ import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
 public class JsonFileCompare {
+  private static Logger log = LoggerFactory.getLogger(JsonFileCompare.class);
 
   public static void main(String[] args) {
-
-
     try {
       ObjectMapper objectMapper = new ObjectMapper();
       Path originPath = Paths.get(args[0]);
@@ -25,12 +25,12 @@ public class JsonFileCompare {
       IntStream.range(1, args.length).forEach(i -> findMissingKeys(Paths.get(args[i]), originSet));
 
     } catch (Exception e) {
-      System.err.println(args[0] + " is not exists or not json files.");
+      log.error("{} is not exists or not json files.", args[0], e);
       System.exit(1);
     }
   }
 
-  public static void addKeys(String currentPath, JsonNode jsonNode, Set set, List<Integer> suffix) {
+  private static void addKeys(String currentPath, JsonNode jsonNode, Set<String> set, List<Integer> suffix) {
     if (jsonNode.isObject()) {
       ObjectNode objectNode = (ObjectNode) jsonNode;
       Iterator<Map.Entry<String, JsonNode>> iter = objectNode.fields();
@@ -40,29 +40,19 @@ public class JsonFileCompare {
         Map.Entry<String, JsonNode> entry = iter.next();
         addKeys(pathPrefix + entry.getKey(), entry.getValue(), set, suffix);
       }
-    } else if (jsonNode.isArray()) {
-      ArrayNode arrayNode = (ArrayNode) jsonNode;
-
-      for (int i = 0; i < arrayNode.size(); i++) {
-        suffix.add(i + 1);
-        addKeys(currentPath, arrayNode.get(i), set, suffix);
-
-        if (i + 1 < arrayNode.size()) {
-          suffix.remove(arrayNode.size() - 1);
-        }
-      }
 
     } else if (jsonNode.isValueNode()) {
+      StringBuilder sb = new StringBuilder(currentPath);
       if (currentPath.contains("-")) {
-        for (int i = 0; i < suffix.size(); i++) {
-          currentPath += "-" + suffix.get(i);
+        for (Integer suffix1 : suffix) {
+          sb.append("-").append(suffix1);
         }
       }
-      set.add(currentPath);
+      set.add(sb.toString());
     }
   }
 
-  public static void findMissingKeys(Path targetPath, Set<String> originSet) {
+  private static void findMissingKeys(Path targetPath, Set<String> originSet) {
     if (!targetPath.toFile().exists()) return;
     try {
       Set<String> targetSet = new HashSet<>();
@@ -76,13 +66,11 @@ public class JsonFileCompare {
               .filter(key -> !targetSet.contains(key))
               .collect(Collectors.toSet());
       if (!missingKey.isEmpty()) {
-        System.err.println("Missing Key on " + targetPath.toString());
-        System.err.println("Missing Keys: ");
-        missingKey.stream().sorted().forEach(System.err::println);
+        log.error("Missing Key on {} \n Missing Keys: {}", targetPath, missingKey.stream().sorted().collect(Collectors.toList()));
         System.exit(1);
       }
     } catch (Exception e) {
-      System.err.println(targetPath.toString() + " is not json files.");
+      log.error("{} is not json files.", targetPath, e);
       System.exit(1);
     }
   }