?? ?@Bean
?? ?public ObjectMapper jacksonObjectMapper() {
?? ??? ?ObjectMapper objectMapper = new ObjectMapper();
?? ??? ?// objectMapper.setSerializationInclusion(Include.NON_NULL);
?? ??? ?objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
?? ??? ??? ?@Override
?? ??? ??? ?public void serialize(Object value, JsonGenerator jg, SerializerProvider sp)
?? ??? ??? ??? ?throws IOException, JsonProcessingException {
?? ??? ??? ??? ?jg.writeString("");
?? ??? ??? ??? ?sp.getDefaultNullKeySerializer();
?? ??? ??? ?}
?? ??? ?});
?? ??? ?objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
?? ??? ?return objectMapper;
?? ?}

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
import org.springframework.cloud.openfeign.support.ResponseEntityDecoder;
import org.springframework.cloud.openfeign.support.SpringDecoder;
import org.springframework.cloud.openfeign.support.SpringEncoder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import feign.codec.Decoder;
import feign.codec.Encoder;
@Configuration
public class CustomFeignConfig {
? ? @Bean
? ? public Decoder feignDecoder() {
? ? ? ? HttpMessageConverter jacksonConverter = new MappingJackson2HttpMessageConverter(customObjectMapper());
? ? ? ? ObjectFactory<HttpMessageConverters> objectFactory = () -> new HttpMessageConverters(jacksonConverter);
? ? ? ? return new ResponseEntityDecoder(new SpringDecoder(objectFactory));
? ? }
? ? @Bean
? ? public Encoder feignEncoder(){
? ? ? ? HttpMessageConverter jacksonConverter = new MappingJackson2HttpMessageConverter(customObjectMapper());
? ? ? ? ObjectFactory<HttpMessageConverters> objectFactory = () -> new HttpMessageConverters(jacksonConverter);
? ? ? ? return new SpringEncoder(objectFactory);
? ? }
? ? public ObjectMapper customObjectMapper(){
? ? ? ? ObjectMapper objectMapper = new ObjectMapper();
? ? ? ? //Customize as much as you want
? ? ? ? objectMapper.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
? ? ? ? return objectMapper;
? ? }
}

public ObjectMapper customObjectMapper(){
? ? ? ? ObjectMapper objectMapper = new ObjectMapper();
? ? ? ? //Customize as much as you want
?? ??? ?objectMapper.registerModule(new StringSanitizerModule());
? ? ? ? return objectMapper;
}
public class StringSanitizerModule extends SimpleModule {
? ? public StringSanitizerModule() {
? ? ? ? addDeserializer(String.class, new StdScalarDeserializer<String>(String.class) {
? ? ? ? ? ? @Override
? ? ? ? ? ? public String deserialize(JsonParser jsonParser, DeserializationContext ctx) throws IOException {
? ? ? ? ? ? ? ?return StringUtils.trimToNull(jsonParser.getValueAsString());
? ? ? ? ? ? }
? ? ? ? });
? ? }
}