private ObjectMapper getObjectMapper() throws IOException {
if (this.objectMapper == null) {
ObjectMapper objectMapper = new ObjectMapper();
AnnotationIntrospector introspector = new JaxbAnnotationIntrospector();
SerializationConfig serializationConfig = objectMapper.getSerializationConfig();
serializationConfig = serializationConfig.without(SerializationConfig.Feature.WRAP_ROOT_VALUE)
.with(SerializationConfig.Feature.INDENT_OUTPUT)
.withSerializationInclusion(JsonSerialize.Inclusion.NON_NULL)
.withSerializationInclusion(JsonSerialize.Inclusion.NON_EMPTY)
.withAnnotationIntrospector(introspector);
objectMapper.setSerializationConfig(serializationConfig);