builder.setVersion(version.doubleValue());
// if (StringUtil.isEmpty(datePattern))
// datePattern = DEFAULT_DATE_PATTERN;
builder.setDateFormat(datePattern);
if (excludesFieldsWithoutExpose)
builder.excludeFieldsWithoutExposeAnnotation();
String result = null;
Gson gson = builder.create();
try {
if (targetType != null) {
result = gson.toJson(target, targetType);