public static String toJson(Object value) {
try {
return mapper.writeValueAsString(value);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

public static <T> T toObject(String json, Class<T> valueType) {
Assert.hasText(json);
Assert.notNull(valueType);
try {
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
mapper.setDateFormat(dateFormat);
return mapper.readValue(json, valueType);
} catch (Exception e) {
e.printStackTrace();
}
return null;