Could not extract response: no suitable HttpMessageConverter found for content type [xxx]

当我们使用Spring RestTemplate进行HTTP请求时，有时会遇到"Could not extract response: no suitable HttpMessageConverter found for content type [xxx]"的错误。这是因为RestTemplate默认使用的HttpMessageConverter无法处理返回的数据类型。解决这个问题的方法是添加一个能够处理该数据类型的HttpMessageConverter。

以下是两种解决方法：

1.使用MappingJackson2HttpMessageConverter

RestTemplate restTemplate = new RestTemplate();
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
converter.setSupportedMediaTypes(Collections.singletonList(MediaType.valueOf("application/vnd.github.v3+json")));
restTemplate.getMessageConverters().add(converter);

2.自定义HttpMessageConverter

public class MyHttpMessageConverter extends AbstractHttpMessageConverter<Object> {

    public MyHttpMessageConverter() {
        super(MediaType.valueOf("application/vnd.github.v3+json"));
    }

    @Override
    protected boolean supports(Class<?> clazz) {
        return true;
    }

    @Override
    protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
        // 处理返回的数据
        return null;
    }

    @Override
    protected void writeInternal(Object o, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException {
        // 处理发送的数据
    }
}

然后将自定义的HttpMessageConverter添加到RestTemplate中：

RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new MyHttpMessageConverter());