import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;

import java.io.IOException;

/**
* @author Dongguabai
* @date 2018/10/19 17:13
*/
public class JsonObjectMapper extends ObjectMapper {
private static final long serialVersionUID = 1L;

public JsonObjectMapper() {
super();
this.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
@Override
public void serialize(Object value, JsonGenerator jg, SerializerProvider sp) throws IOException, JsonProcessingException {
jg.writeString("");
}
});
}
}

SpringMVC配置文件:

<bean id="mappingJacksonHttpMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/html;charset=UTF-8</value>
</list>
</property>
<property name="objectMapper">
<bean class="com.api.framwork.converter.JsonObjectMapper"/>
</property>
</bean>

其实这里方法有很多,可以自行扩展:

SpringMVC Jackson为null转化为空串处理_java