添加JSON helper

src/src/main/java/com/my/graphiteDigesterBg/diframe/util/DiJsonHelper.java

@@ -0,0 +1,13 @@
+package com.my.graphiteDigesterBg.diframe.util;
+import com.fasterxml.jackson.databind.ObjectMapper;
+public class DiJsonHelper {
+    // object to json
+    public static String objectToJson( Object obj ) {
+        ObjectMapper mapper = new ObjectMapper();
+        try {
+            return mapper.writeValueAsString(obj);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}