spring boot2 修改默认json解析器Jackson为fastjson

        <dependency>
            <groupid>com.alibaba</groupid>
            <artifactid>fastjsonlt;/artifactid>
            <version>1.2.62lt;/version>
        </dependency>

注意：Springboot2.0以后，WebMvcConfigurerAdapter 过时了， 以前1版本继承WebMvcConfigurerAdapter 来实现的方法不推荐了。下面介绍两种配置方式，还有一种实现WebMvcConfigurationSupport的方式就不介绍了，道路千万条，选一条就足够了：

方式一（推荐）：用bean替代默认解析器

package com.anson.config;

import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.support.config.FastJsonConfig;
import com.alibaba.fastjson.support.spring.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 org.springframework.http.converter.HttpMessageConverter;

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

@Configuration
public class WebConfig {

    /**
     * @Author anson
     * @Description 配置消息转换器
     * @Date: 2019-12-8 11:23:33
     * @version: 1.0
     * new HttpMessageConverters(true, converters);
     * 一定要设为true才能替换否则不会替换
     * @return 返回一个消息转换的bean
     */
    @Bean
    public HttpMessageConverters fastJsonMessageConverters() {
        List> converters = new ArrayList<>();
        //需要定义一个convert转换消息的对象;
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        //添加fastJson的配置信息;
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);
        //全局时间配置
        fastJsonConfig.setDateFormat("yyyy-MM-dd HH:mm:ss");
        fastJsonConfig.setCharset(Charset.forName("UTF-8"));
        //处理中文乱码问题
        List fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        //在convert中添加配置信息.
        fastConverter.setSupportedMediaTypes(fastMediaTypes);
        fastConverter.setFastJsonConfig(fastJsonConfig);

        converters.add(0, fastConverter);
        return new HttpMessageConverters(converters);
    }
}

方式二、实现WebMvcConfigurer

@Configuration
public class WebConfigure implements WebMvcConfigurer{
 
    /**
     * 配置消息转换器
     * @param converters
     */
    @Override
    public void configureMessageConverters(List> converters) {
       //需要定义一个convert转换消息的对象;
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        //添加fastJson的配置信息;
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);
        //全局时间配置
        fastJsonConfig.setDateFormat("yyyy-MM-dd HH:mm:ss");
        fastJsonConfig.setCharset(Charset.forName("UTF-8"));
        //处理中文乱码问题
        List fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        //在convert中添加配置信息.
        fastConverter.setSupportedMediaTypes(fastMediaTypes);
        fastConverter.setFastJsonConfig(fastJsonConfig);
        converters.add(0,fastConverter);
    }
}