Springboot接收前端的Json但是为null问题
作者：无相孤君
这篇文章主要介绍了Springboot接收前端的Json但是为null问题,具有很好的参考价值,希望对大家有所帮助,如有错误或未考虑完全的地方,望不吝赐教<BR>
Springboot接收前端的Json但是为null
接收前端传过来的Json，
{
"id": 94,
"nickname": "王明",
"username": "萧强",
"password": "nulla",
"email": "p.tplfsayobt@qq.com",
"avatar": "http://dummyimage.com/100x100",
"type": 47,
"createTime": "2007-12-03 08:23:55",
"updateTime": "1972-02-26 05:02:56"
}然后反序列化转化成User实体类，打印实体类为空，仔细检查了一下。
@PostMapping(value = "/register")
public Result registerUser(User user) {
userService.register(user);
return ResultGenerator.getSuccessResult(user);
}
少了@RequestBody注解
@PostMapping(value = "/register")
public Result registerUser(@RequestBody User user) {
userService.register(user);
return ResultGenerator.getSuccessResult(user);
}现在实体类就有数据了。
Springboot将返回前端的null值变为固定值
做了个项目 当我给前端返回null值时需求要把 null值都返回成 “–” 记录一下子
在springboot上配置一下就好
import com.fasterxml.jackson.core.JsonGenerator;
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;
/**
* @author : Nan
* @date : 2021/06/20
* @description :
*/
@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, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, IOException {
// 这里可以给任意值 将返回null的值替换 但是目前不知道还想返回null怎么办
jsonGenerator.writeString("--");
}
});
return objectMapper;
}
}
总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。