Jersey REST-Client WebTarget - 无法找到内容类型的 MessageBodyReader

Question

这是关于参数化的请求。我的应用程序的用户应该能够为请求选择参数。然后我将从响应中读取 xml 并使用 JAXB 对其进行解析。我是这样成功完成的：

String uri = "https://cmi.zb.uzh.ch/primo/api/oaipmh?verb=ListRecords&metadataPrefix=oai_primo&set=PRIMO&from=2020-01-22T12:39:59Z&until=2020-02-28T11:40:00Z";
            URL url = new URL(uri);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.setRequestProperty("Accept", "application/xml");

            JAXBContext jaxbContext = JAXBContext.newInstance(ObjectFactory.class);
            InputStream xml = connection.getInputStream();

            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            oai = (OAIPMHtype) jaxbUnmarshaller.unmarshal(xml);

但我想动态创建请求。有一个 JSF 页面，用户可以在其中输入参数。我想到了一个 Jersey-Client，因为我可以很容易地用字段替换 queryParam 中的字符串。但是我不能 link Jersey-Client 到我的 Unmarshaller。

我的想法是将响应转换为输入流并将其提供给 Unmarshaller。

这是我试过的。

主要方法

public static void main(String[] args) {
        ClientConfig config = new ClientConfig();
        Client client = ClientBuilder.newClient(config);
            WebTarget target = client.target("https://cmi.zb.uzh.ch/primo/api/oaipmh");
             target.queryParam("verb", "ListRecords")
                    .queryParam("metadataPrefix", "oai-primo")
                    .queryParam("set", "PRIMO")
                    .queryParam("from", "2020-01-22T12:39:59Z")
                    .queryParam("until", "2020-02-28T11:40:00Z" );

            InputStream stream = target.request()
                    .accept(MediaType.TEXT_XML)
                    .get(InputStream.class);

    }
}

错误信息

Exception in thread "main" javax.ws.rs.client.ResponseProcessingException: javax.ws.rs.ProcessingException: RESTEASY003145: Unable to find a MessageBodyReader of content-type text/xml;charset=utf-8 and type class java.io.InputStream
    at org.jboss.resteasy.client.jaxrs.internal.ClientInvocation.extractResult(ClientInvocation.java:163)
    at org.jboss.resteasy.client.jaxrs.internal.ClientInvocation.invoke(ClientInvocation.java:467)
    at org.jboss.resteasy.client.jaxrs.internal.ClientInvocationBuilder.get(ClientInvocationBuilder.java:197)
    at ch.hbu.sacker.oaipmh.VogellaExample.main(VogellaExample.java:45)
Caused by: javax.ws.rs.ProcessingException: RESTEASY003145: Unable to find a MessageBodyReader of content-type text/xml;charset=utf-8 and type class java.io.InputStream
    at org.jboss.resteasy.core.interception.ClientReaderInterceptorContext.throwReaderNotFound(ClientReaderInterceptorContext.java:37)
    at org.jboss.resteasy.core.interception.AbstractReaderInterceptorContext.getReader(AbstractReaderInterceptorContext.java:80)
    at org.jboss.resteasy.core.interception.AbstractReaderInterceptorContext.proceed(AbstractReaderInterceptorContext.java:53)
    at org.jboss.resteasy.client.jaxrs.internal.ClientResponse.readFrom(ClientResponse.java:211)
    at org.jboss.resteasy.specimpl.BuiltResponse.readEntity(BuiltResponse.java:88)
    at org.jboss.resteasy.specimpl.AbstractBuiltResponse.readEntity(AbstractBuiltResponse.java:256)
    at org.jboss.resteasy.client.jaxrs.internal.ClientInvocation.extractResult(ClientInvocation.java:127)
    ... 3 more

有人知道为什么会这样吗？

Answer 1

您尝试使用 3d 派对 Http 客户端而不是使用 HttpURLConnection class 是正确的。您可以做的是尝试一些其他可用的 HTTP 客户端。受欢迎的是 Apache Http Client or OK Http client。但是，我也可以建议我自己的带有 Http 客户端的开源 MgntUtils 库。它可能不像其他库那么广泛，但非常简单，适合向同一个 URL 多次发送请求。如果您想使用我的库，您的代码将如下所示

HttpClient client = new HttpClient();
client.setConnectionUrl("https://cmi.zb.uzh.ch/primo/api/oaipmh?verb=ListRecords&metadataPrefix=oai_primo&set=PRIMO&from=2020-01-22T12:39:59Z&until=2020-02-28T11:40:00Z");
client.setRequestProperty("Accept", "application/xml");
String xmlStr = client.sendHttpRequest(HttpMethod.GET);

这是 HttpClient class. The library could be obtained as Maven artifacts or on Github 的 Javadoc（带有源代码和 Javadoc）

Answer 2

问题是 WebTarget 使用上面的代码，请求只调用了这个 URL https://cmi.zb.uzh.ch/primo/api/oaipmh?verb=ListRecords 这确实会导致错误！

<OAI-PMH>
<responseDate>2021-02-07T10:06:28Z</responseDate>
<request verb="ListRecords">https://cmi.zb.uzh.ch/primo/api/oaipmh</request>
<error code="badArgument">Unknown arguments: </error>
</OAI-PMH>

如此处所述我不得不覆盖目标。

    WebTarget target = client.target("https://cmi.zb.uzh.ch/primo/api/oaipmh?verb=ListRecords");

        target = target.queryParam("metadataPrefix", "oai_primo")
                .queryParam("set", "PRIMO")
                .queryParam("from", "2020-01-22T12:39:59Z")
                .queryParam("until", "2020-02-28T11:40:00Z" );

Jersey REST-Client WebTarget - 无法找到内容类型的 MessageBodyReader

Jersey REST-Client WebTarget - Unable to find a MessageBodyReader of content-type

java

unmarshalling

rest-client