[JAVA]Springboot添加fastjson用于前台数据校验

方式一，添加HttpMessageConverters实例

import com.alibaba.fastjson.support.config.FastJsonConfig;
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
import org.springframework.boot.autoconfigure.web.HttpMessageConverters;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;

/**
 * json填充到java对象
 */
@Configuration
public class MyConverter {
    @Bean
    public HttpMessageConverters fastJsonHttpMessageConverters() {
        // 1、需要先定义一个 convert 转换消息的对象;
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();

        //2、添加fastJson 的配置信息，比如：是否要格式化返回的json数据;
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        // fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);

        //3、在convert中添加配置信息.
        fastConverter.setFastJsonConfig(fastJsonConfig);

        HttpMessageConverter<?> converter = fastConverter;
        return new HttpMessageConverters(converter);
    }
}

 

方式二，继承WebMvcConfigurationSupport

import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.support.config.FastJsonConfig;
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.List;

@Configuration
public class BackendWebMvcConfig extends WebMvcConfigurationSupport {
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        //定义一个convert转换消息的对象
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        //添加fastjson的配置信息，比如是否要格式化返回的json数据；
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(
            //是否输出值为null的字段,默认为false
            SerializerFeature.WriteMapNullValue,
            //将Collection类型字段的字段空值输出为[]
            SerializerFeature.WriteNullListAsEmpty,
            //将字符串类型字段的空值输出为空字符串
            SerializerFeature.WriteNullStringAsEmpty);
        //在convert中添加配置信息
        fastConverter.setFastJsonConfig(fastJsonConfig);
        //设置支持的媒体类型
        fastConverter.setSupportedMediaTypes(Collections.singletonList(MediaType.APPLICATION_JSON));
        //设置默认字符集
        fastConverter.setDefaultCharset(StandardCharsets.UTF_8);
        //将convert添加到converters
        converters.add(0, fastConverter);
        //解决返回字符串带双引号问题
        StringHttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter();
        stringHttpMessageConverter.setSupportedMediaTypes(Collections.singletonList(MediaType.TEXT_PLAIN));
        stringHttpMessageConverter.setDefaultCharset(StandardCharsets.UTF_8);
        converters.add(0, stringHttpMessageConverter);
        super.addDefaultHttpMessageConverters(converters);
    }
}

 

问题记录：

   1、对象校验报错： 

/**
 * 用户id
 */
@JSONField(name = "user_id")
@NotEmpty()
private Long userId;

报：No validator could be found for constraint 'javax.validation.constraints.NotEmpty' validating type 'java.lang.Long'. Check configuration for 'userId'

NotEmpty只能用于string判空，Long类型不支持，改成@NotNull

说明：
1、restful接口中使用注解@Validate和Valid都可用，Validated支持分组

@PostMapping(value = "edit")
@ResponseBody
public HttpResult edit(@RequestBody @Validate User user) {}