Spring Boot-HttpMessageConverter JSONP（应用程序/javascript）

Question

我调用了一个RESTendpoint，该endpoint在响应体中返回基本JSON，但内容类型响应头设置为application/javascript。

这是我的标准RestTemboard bean：

 RestTemplateBuilder restBuilder = new RestTemplateBuilder();
    return restBuilder.setConnectTimeout(connectTimeout)
            .setReadTimeout(readTimeout)
            .build();

当我使用此模板发出getForObject请求时，默认转换器无法处理响应，我得到一个异常：

org.springframework.web.client.RestClientException：无法提取响应：没有找到合适的HttpMessageConverter的响应类型[类我的响应Obj]和内容类型[应用程序/javascript]

在通常的转换之前，是否有一些快速配置可以添加到RestTemplate中以处理此响应？

我目前的工作只是将响应转换为String而不是我的域对象，然后使用ObjectMapper手动创建我的对象，但这感觉有点脏。

Answer 1

您应该能够自定义HttpMessageConverter，以使用应用程序/javascript媒体类型：https://dzone.com/articles/customizing

这样的东西可能有用，但我没有测试这个：

    @Bean
    public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter() {
        MappingJackson2HttpMessageConverter jsonConverter = new MappingJackson2HttpMessageConverter();
        jsonConverter.getSupportedMediaTypes().add(new MediaType("application/javascript"));

        return jsonConverter;
    }

现在，我改编自的教程重点关注RestController，而不是RestTemplate。如果不起作用，可以手动创建converter对象，并在RestTemplate对象上设置HttpMessageConverters，而不是使用bean：

restTemplate.getMessageConverters().add(jsonConverter);

关键是将适当的转换器映射到正确的媒体类型，在您的应用程序/javascript中。

Answer 2

我发现的最佳选择如下：

//Create a new converter class, that it's basically the same jackson, but it works with when header is javascript
public class JavaScriptMessageConverter extends AbstractJackson2HttpMessageConverter {

    //Add a new mediatype converter
    private JavaScriptMessageConverter() {
        super(Jackson2ObjectMapperBuilder.json().build(),new MediaType("application","javascript"));
    }
}

//Other class...

//Then add the converter to your rest template
restTemplate.getMessageConverters().add(new JavaScriptMessageConverter());
//Of course you can define the class also a bean and have it as singleton

我检查了这个免费的API，这正是你的问题：http://api.coindesk.com/v1/bpi/currentprice.json

16-11-2018 12:02:06.885 [http-nio-12000-exec-1] [process,,,] [] INFO  i.z.m.w.r.ArchRestLoggingInterceptor.logResponse - BitcoinService, Response with status code: 200, headers: {Content-Type=[application/javascript], Content-Length=[672], Access-Control-Allow-Origin=[*], Cache-Control=[max-age=15], Date=[Fri, 16 Nov 2018 11:02:06 GMT], Expires=[Fri, 16 Nov 2018 11:03:07 UTC], Server=[nginx/1.12.1], X-Powered-By=[Fat-Free Framework], X-Cache=[Miss from cloudfront, MISS from ced01squidp02.replynet.prv], X-Amz-Cf-Id=[v3NAF9Z0C5SiQrgLuAsxDgUQBP1-oLWUviHvS_9mOaFk7XrSAu7ZMQ==], X-Cache-Lookup=[MISS from ced01squidp02.replynet.prv:8080], Via=[1.1 1b96443527f684c809162d975cdd968f.cloudfront.net (CloudFront), 1.1 ced01squidp02.replynet.prv (squid/3.5.21)], Connection=[keep-alive]}, raw response: {"time":{"updated":"Nov 16, 2018 11:02:00 UTC","updatedISO":"2018-11-16T11:02:00+00:00","updateduk":"Nov 16, 2018 at 11:02 GMT"},"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchan...org","chartName":"Bitcoin","bpi":{"USD":{"code":"USD","symbol":"$","rate":"5,583.3925","description":"United States Dollar","rate_float":5583.3925},"GBP":{"code":"GBP","symbol":"£","rate":"4,363.6892","description":"British Pound Sterling","rate_float":4363.6892},"EUR":{"code":"EUR","symbol":"€","rate":"4,923.4020","description":"Euro","rate_float":4923.402}}}