diff --git a/src/main/java/com/yexuejc/base/util/JsonUtil.java b/src/main/java/com/yexuejc/base/util/JsonUtil.java
index 9a7ae1d..a83aa68 100644
--- a/src/main/java/com/yexuejc/base/util/JsonUtil.java
+++ b/src/main/java/com/yexuejc/base/util/JsonUtil.java
@@ -1,5 +1,14 @@
 package com.yexuejc.base.util;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.Timestamp;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.Map;
+import java.util.TimeZone;
+import java.util.logging.Logger;
+
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonParseException;
@@ -24,15 +33,6 @@ import com.yexuejc.base.converter.LocalDateTimeSerializer;
 import com.yexuejc.base.converter.TimestampDeserializer;
 import com.yexuejc.base.converter.TimestampSerializer;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.sql.Timestamp;
-import java.time.LocalDate;
-import java.time.LocalDateTime;
-import java.util.Map;
-import java.util.TimeZone;
-import java.util.logging.Logger;
-
 /**
  * json工具类，基于jackson
  *
@@ -42,7 +42,7 @@ import java.util.logging.Logger;
  * @date 2018/9/3 15:28
  */
 public class JsonUtil {
-    private static Logger log = Logger.getLogger(JsonUtil.class.getName());
+    private static final Logger log = Logger.getLogger(JsonUtil.class.getName());
 
     private JsonUtil() {
     }
@@ -50,10 +50,9 @@ public class JsonUtil {
     /**
      * 作为单例全局使用
      */
-    private static JsonMapper jsonMapper = new JsonMapper();
+    private static final JsonMapper jsonMapper = new JsonMapper();
 
     static {
-        JsonUtil.setJavaTimeModule(JsonUtil.jsonMapper);
         JsonUtil.initDefaultObjectMapper(JsonUtil.jsonMapper);
     }
 
@@ -94,14 +93,17 @@ public class JsonUtil {
      * </pre>
      *
      * @param jsonMapper
+     * @return
      */
-    private static void initDefaultObjectMapper(ObjectMapper jsonMapper) {
+    private static ObjectMapper initDefaultObjectMapper(ObjectMapper jsonMapper) {
+        JsonUtil.setJavaTimeModule(jsonMapper);
         //值为空时，NON_NULL：舍去字段；ALWAYS:保留字段
         jsonMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
         jsonMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
         jsonMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
         jsonMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
         jsonMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
+        return jsonMapper;
     }
 
     /**
@@ -121,8 +123,7 @@ public class JsonUtil {
      *
      * @return
      */
-    public static ObjectMapper acceptEmptyStringAsNullObject() {
-        JsonMapper jsonMapper = new JsonMapper();
+    public static ObjectMapper acceptEmptyStringAsNullObject(JsonMapper jsonMapper) {
         setJavaTimeModule(jsonMapper);
         //值为空时，ALWAYS:保留字段，默认字符串值为“”，对象值为null
         jsonMapper.setSerializationInclusion(JsonInclude.Include.ALWAYS);