SpringBoot配置FastJson的时候，报错：

java.lang.IllegalArgumentException: Content-Type cannot contain wildcard type '*'
    at org.springframework.util.Assert.isTrue(Assert.java:116) ~[spring-core-5.0.13.RELEASE.jar!/:5.0.13.RELEASE]
    at org.springframework.http.HttpHeaders.setContentType(HttpHeaders.java:861) ~[spring-web-5.0.13.RELEASE.jar!/:5.0.13.RELEASE]
    at org.springframework.http.converter.AbstractHttpMessageConverter.addDefaultHeaders(AbstractHttpMessageConverter.java:255) ~[spring-web-5.0.13.RELEASE.jar!/:5.0.13.RELEASE]
    at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:210) ~[spring-web-5.0.13.RELEASE.jar!/:5.0.13.RELEASE]
    at com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter.write(FastJsonHttpMessageConverter.java:244) ~[fastjson-1.2.57.jar!/:?]

看FastJson初始化：

public static final MediaType ALL = valueOf("*/*");
public FastJsonHttpMessageConverter() {
    super(MediaType.ALL);  // */*
}

看来不能有通配符，所以需要像下面配置：

@Bean
public HttpMessageConverters fastJsonHttpMessageConverters() {
    //创建FastJson信息转换对象
    FastJsonHttpMessageConverter fastJsonHttpMessageConverter =
            new FastJsonHttpMessageConverter();

    List<MediaType> supportedMediaTypes = Lists.newArrayList();
    //从1.1.41升级到1.2.之后的版本必须配置，否则会报错
    supportedMediaTypes.add(MediaType.APPLICATION_JSON);
    supportedMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
    fastJsonHttpMessageConverter.setSupportedMediaTypes(supportedMediaTypes);

    //创建FastJson对象并设定序列化规则
    FastJsonConfig fastJsonConfig = new FastJsonConfig();
    //添加自定义valueFilter
    //规则赋予转换对象
    fastJsonHttpMessageConverter.setFastJsonConfig(fastJsonConfig);
    StringHttpMessageConverter stringHttpMessageConverter =
            new StringHttpMessageConverter(Charset.defaultCharset());

    fastJsonConfig.setSerializerFeatures(
            //消除对同一对象循环引用的问题，默认为false（如果不配置有可能会进入死循环）
            SerializerFeature.DisableCircularReferenceDetect,
            //是否输出值为null的字段,默认为false
            SerializerFeature.WriteMapNullValue
    );

    return new HttpMessageConverters(fastJsonHttpMessageConverter, stringHttpMessageConverter);
}