springboot笔记示例六：fastjson2集成

springboot笔记示例六：fastjson2集成

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#springboot json官方说明

https://docs.spring.io/spring-boot/docs/2.1.6.RELEASE/reference/html/boot-features-json.html

spring Boot 提供与三个 JSON 映射库的集成：

• Gson
• Jackson
• JSON-B

springboot 默认库为：Jackson

 <!-- springboot-json -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-json</artifactId>
    </dependency>

yml配置自定义序列化格式

spring:
  jackson:
    # @JsonFormat 日期格式和时区配置
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8
    property-naming-strategy: SNAKE_CASE

阿里巴巴FastJson2集成

spring5.x

<dependency>
    <groupId>com.alibaba.fastjson2</groupId>
    <artifactId>fastjson2</artifactId>
    <version>2.0.43</version>
</dependency>
<dependency>
    <groupId>com.alibaba.fastjson2</groupId>
    <artifactId>fastjson2-extension-spring5</artifactId>
    <version>2.0.43</version>
</dependency>

package com.brm.config;

import com.alibaba.fastjson2.JSONReader;
import com.alibaba.fastjson2.JSONWriter;
import com.alibaba.fastjson2.support.config.FastJsonConfig;
import com.alibaba.fastjson2.support.spring.http.converter.FastJsonHttpMessageConverter;
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;

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

@Configuration
public class FastjsonConfiguration {

    @Bean
    public HttpMessageConverters fastJsonConfigure() {

        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        //fastjson2 默认格式为yyyy-MM-dd HH:mm 无需重新设置
        fastJsonConfig.setDateFormat("yyyy-MM-dd HH:mm:ss");
        //fastjson2 默认StandardCharsets.UTF_8 无需重新设置
//        fastJsonConfig.setCharset(StandardCharsets.UTF_8);

        fastJsonConfig.setReaderFeatures(
                //字段如 vBtn  会被转为 VBtn  处理这样的问题
                JSONReader.Feature.SupportSmartMatch,
                JSONReader.Feature.FieldBased,
                //初始化String字段为空字符串""
//                JSONReader.Feature.InitStringFieldAsEmpty,
                //对读取到的字符串值做trim处理
                JSONReader.Feature.TrimString);

        fastJsonConfig.setWriterFeatures(
                //字段如 vBtn  会被转为 VBtn  处理这样的问题
                JSONWriter.Feature.FieldBased,
                //long 转 string 丢失精度问题
                JSONWriter.Feature.WriteLongAsString,
                // 保留map空的字段
                JSONWriter.Feature.WriteMapNullValue,
                //将List类型的null转成[]
                JSONWriter.Feature.WriteNullListAsEmpty,
                //将String类型的null转成""
                JSONWriter.Feature.WriteNullStringAsEmpty,
                //将Boolean类型的null转成false
//                JSONWriter.Feature.WriteNullBooleanAsFalse,
                //日期格式转换
                JSONWriter.Feature.PrettyFormat
                //将空置输出为缺省值，Number类型的null都输出为0，String类型的null输出为""，数组和Collection类型的输出为[]
//                JSONWriter.Feature.NullAsDefaultValue
        );

        fastJsonHttpMessageConverter.setFastJsonConfig(fastJsonConfig);
        List<MediaType> supportedMediaTypes = new ArrayList<>();
        supportedMediaTypes.add(MediaType.APPLICATION_JSON);
//        supportedMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        supportedMediaTypes.add(MediaType.APPLICATION_ATOM_XML);
        supportedMediaTypes.add(MediaType.APPLICATION_FORM_URLENCODED);
        supportedMediaTypes.add(MediaType.APPLICATION_OCTET_STREAM);
        supportedMediaTypes.add(MediaType.APPLICATION_PDF);
        supportedMediaTypes.add(MediaType.APPLICATION_RSS_XML);
        supportedMediaTypes.add(MediaType.APPLICATION_XHTML_XML);
        supportedMediaTypes.add(MediaType.APPLICATION_XML);
        supportedMediaTypes.add(MediaType.IMAGE_GIF);
        supportedMediaTypes.add(MediaType.IMAGE_JPEG);
        supportedMediaTypes.add(MediaType.IMAGE_PNG);
        supportedMediaTypes.add(MediaType.TEXT_EVENT_STREAM);
        supportedMediaTypes.add(MediaType.TEXT_HTML);
        supportedMediaTypes.add(MediaType.TEXT_MARKDOWN);
        supportedMediaTypes.add(MediaType.TEXT_PLAIN);
        supportedMediaTypes.add(MediaType.TEXT_XML);
        
        fastJsonHttpMessageConverter.setSupportedMediaTypes(supportedMediaTypes);
        fastJsonHttpMessageConverter.setDefaultCharset(StandardCharsets.UTF_8);

        return new HttpMessageConverters(fastJsonHttpMessageConverter);
    }
}