如何在 Jackson xml 解析器中将八位字节流解析为 json？

Question

我有时会收到设置了content-type=application/octet-stream 的网络服务响应，但实际上它是application/xml。

由于我无法控制 web 服务，我仍然想告诉 jackson（我与 spring-boot 一起使用）将这些响应解析为 xml。但是怎么做呢？

我首先尝试为 jackson 映射器完全允许八位字节流，它目前有效：

@Bean
public RestTemplateCustomizer customizeJackson2MessageConverter() {
    return restTemplate -> {
        for (var converter : restTemplate.getMessageConverters()) {
            if (converter instanceof MappingJackson2HttpMessageConverter) { 
                jackson.getSupportedMediaTypes().add((MediaType.APPLICATION_OCTET_STREAM);
            }
        }
    };
}

但是：当涉及到解析时，我如何告诉杰克逊忽略/重写内容类型，并且仍然将其解析为普通 json？

Caused by: org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unexpected character ('<' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null'); nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character ('<' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
 at [Source: (ByteArrayInputStream); line: 1, column: 2]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:245) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:227) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:102) ~[spring-web-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 113 more

Answer 1

我按照@chrylis 的建议做了：

public class ContentTypeInterceptor implements ClientHttpRequestInterceptor {
    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        ClientHttpResponse http = execution.execute(request, body);

        HttpHeaders headers = http.getHeaders();
        if (headers.getContentType() == MediaType.APPLICATION_OCTET_STREAM) {
            headers.setContentType(MediaType.APPLICATION_XML);
        }

        return http;
    }
}