SpringCloud : Feign 使用 FastJson 解析數據

Fastjson 版本1.2.60

Spring 版本 5.1.5.RELEASE

SpringBoot 版本 2.1.5.RELEASE

SpringCloud 版本 2.1.1.RELEASE

 

SpringCloud 中配置 FastJson 如下：

@Configuration
public class FastJsonConverterConfig extends WebMvcConfigurationSupport {

    /**
     * 使用fastjson代替jackson
     */
    @Override
    protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        //先把JackSon的消息轉換器刪除.
        //(1)源碼分析可知，返回json的過程為:
        //  Controller調用結束后返回一個數據對象，for循環遍歷conventers，找到支持application/json的HttpMessageConverter，然后將返回的數據序列化成json。
        //  具體參考org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor的writeWithMessageConverters方法
        //(2)由於是list結構，我們添加的fastjson在最后。因此必須要將jackson的轉換器刪除，不然會先匹配上jackson，導致沒使用fastjson
        for (int i = converters.size() - 1; i >= 0; i--) {
            if (converters.get(i) instanceof MappingJackson2HttpMessageConverter) {
                converters.remove(i);
            }
        }

        //自定義fastjson配置
        FastJsonConfig config = new FastJsonConfig();
        config.setSerializerFeatures(
                // 是否輸出值為null的字段,默認為false,我們將它打開
                SerializerFeature.WriteMapNullValue,
                // 將Collection類型字段的字段空值輸出為[]
                SerializerFeature.WriteNullListAsEmpty,
                // 將字符串類型字段的空值輸出為空字符串
                SerializerFeature.WriteNullStringAsEmpty,
                // 將數值類型字段的空值輸出為0
                SerializerFeature.WriteNullNumberAsZero,
                SerializerFeature.WriteDateUseDateFormat,
                // 禁用循環引用
                SerializerFeature.DisableCircularReferenceDetect
        );

        // 添加支持的MediaTypes;不添加時默認為*/*,也就是默認支持全部
        // 但是MappingJackson2HttpMessageConverter里面支持的MediaTypes為application/json
        List<MediaType> fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON);
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);

        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();
        fastJsonHttpMessageConverter.setFastJsonConfig(config);
        fastJsonHttpMessageConverter.setSupportedMediaTypes(fastMediaTypes);
        converters.add(fastJsonHttpMessageConverter);
        //支持XML格式的請求
        converters.add(new StringHttpMessageConverter());
    }
}

 

 

但是，在使用Feign的Spring Cloud微服務項目中，要特別注意需要為Feign單獨配置。因為Feign並不共用Spring MVC的消息轉換器鏈，默認使用的是Jackson Json解析庫。

所以需要單獨如下配置：

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.support.config.FastJsonConfig;
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
import com.alibaba.fastjson.support.springfox.SwaggerJsonSerializer;
import feign.Logger;
import feign.codec.Decoder;
import feign.codec.Encoder;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
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.MediaType;

import java.util.ArrayList;
import java.util.List;

/**
 * Feign 客戶端配置
 *
 * @author xushiling
 * @date 2018/8/13
 */
@Configuration
public class FeignConfig {

    @Bean
    Logger.Level feignLoggerLevel() {
        //這里記錄所有，根據實際情況選擇合適的日志level
        return Logger.Level.FULL;
    }

    @Bean
    public Encoder feignEncoder() {
        return new SpringEncoder(feignHttpMessageConverter());
    }

    @Bean
    public Decoder feignDecoder() {
        return new SpringDecoder(feignHttpMessageConverter());
    }

    /**
     * 設置解碼器為fastjson
     *
     * @return
     */
    private ObjectFactory<HttpMessageConverters> feignHttpMessageConverter() {
        final HttpMessageConverters httpMessageConverters = new HttpMessageConverters(this.getFastJsonConverter());
        return () -> httpMessageConverters;
    }

    private FastJsonHttpMessageConverter getFastJsonConverter() {
        FastJsonHttpMessageConverter converter = new FastJsonHttpMessageConverter();

        List<MediaType> supportedMediaTypes = new ArrayList<>();
        MediaType mediaTypeJson = MediaType.valueOf(MediaType.APPLICATION_JSON_UTF8_VALUE);
        supportedMediaTypes.add(mediaTypeJson);
        converter.setSupportedMediaTypes(supportedMediaTypes);
        FastJsonConfig config = new FastJsonConfig();
        config.getSerializeConfig().put(JSON.class, new SwaggerJsonSerializer());
        config.setSerializerFeatures(SerializerFeature.DisableCircularReferenceDetect);
        converter.setFastJsonConfig(config);

        return converter;
    }
}

 

 

PS：

https://blog.csdn.net/lppl010_/article/details/94215233

https://www.jianshu.com/p/b3b93a32cb05