feat(util): add json util class

src/main/java/com/elephant/framework/galaxy/aroad/util/JsonUtil.java

+package com.elephant.framework.galaxy.aroad.util;
+
+import org.codehaus.jackson.map.ObjectMapper;
+
+import java.util.List;
+
+/**
+ * @program:
+ * @description: 序列化工具类
+ * @author: songwenjie
+ * @create: 2019-04-23 17:26
+ **/
+public class JsonUtil {
+    static ObjectMapper objectMapper = new ObjectMapper();
+
+    public static String toJson (Object obj) throws Exception{
+        String json = objectMapper.writeValueAsString(obj);
+        return json;
+    }
+
+    public static Object toObject (String json) throws Exception{
+        Object obj = objectMapper.readValue(json, Object.class);
+        return obj;
+    }
+
+    public static List toList (String json) throws Exception{
+        List list = objectMapper.readValue(json, List.class);
+        return list;
+    }
+}