SpringBoot Return to the JSON data on the page. If there is a data null, return the empty string.

SpringBoot uses Jackson to resolve JSON data.

Let’s do the configuration:

Package com.yhcode.config; 

 Import com.fasterxml.jackson.core.jsongnerator; 
 Import com.fasterxml.jackson.databind.jsonserializer; 
 Import com.fasterxml.jackson.dataBind.objectMapper; 
 Import com.fasterxml.jackson.databind.serializerProvider; 
 Import org.SpringFramework.Boot.autoConfigure.Condition.ConditionalonMissingBean; 
 Import org.springframework.context.annotation.bean; 
 Import org.springframework.context.annotation.configuration; 
 Import org.springframework.context.annotation.primary; 
 Import org.Springframework.http.converter.json.jackson2ObjectMapperbuilder; 

 Import java.io.ioException; 

 /** 
  * Process Null value returned by Jackson 
  * 
  */ 
 @Configuration 
 Public Class JacksonConfig { 

     @Bean 
     @Primary 
     @ConditionalonMissingBean (ObjectMapper.Class) 
     Public ObjectMapper JacksonObjectMapper (Jackson2ObjectMapperBuilder Builder) { 
         ObjectMapper objectMapper = Builder.createxmlMapper (false) .build (); 
         objectMapper.getSerializerProvider (). SetnullValueSerializer (New JSONSERIALIZER <object> () {{ 
             @Override 
             Public Void Serialize (Object O, JSONGENARTOR JSONGENATOR, SerializerProvider Serprovider) Throws IOEXception { 
                 jsongenerator.writeString (""); 
             } 
         }); 
         Return objectmapper; 
     } 
 }

This can turn the NULL value back to JSON into an empty string.