我该如何创建一个Jersey的FormDataContentDisposition对象？

Question

我有一个服务中的以下方法：

public interface MyService {    
    @POST
    @Path("/upload-file")
    @Consumes(MediaType.MULTIPART_FORM_DATA)
    void uploadFile(@FormDataParam("file") InputStream inputStream,
                    @FormDataParam("file") FormDataContentDisposition contentDisposition);
}

我使用WebResourceFactory创建此接口的一个实例：

final MyService buildProxy() {
    final ClientBuilder clientBuidler = ClientBuilder.newBuilder();
    // register components, trust manager, etc.
    final WebTarget target = clientBuilder.build().target("http://myservice.example.com");
    return WebResourceFactory.newResource(
            MyService.class, target, false, ImmutableMultivaluedMap.empty(), 
            Collections.emptyList(), new Form());
}

我想使用这个代理来调用我的方法，但是我找不到一个方便的方法来创建FormDataContentDisposition。难道我的最佳选择真的是创建头字符串，然后将其传递给new FormDataContentDisposition(String header)吗？我能否放宽类型限制以获取更方便的构造函数？在文件上传中，是否有不同的更方便的接口可以使用？我主要在我的接口中包含内容规定，以便在将整个文件保存到磁盘之前拒绝过大的文件。

- Andrew Rueckert

Answer 1

您可以在客户端和服务器参数中都使用FormDataMultipart。FormDataMultiPart以编程方式访问所有主体部分，而不是声明性地访问。这将使您在客户端上拥有更多的自由。请参见下面完整的测试用例。

public class ProxyMultiPartTest extends JerseyTest {

    public static interface IUploadResource {
        @POST
        @Consumes(MediaType.MULTIPART_FORM_DATA)
        String upload(FormDataMultiPart multipart) throws Exception;
    }

    @Path("upload")
    public static class UploadResource implements IUploadResource {
        @Override
        public String upload(FormDataMultiPart multiPart) throws Exception {
            FormDataBodyPart bodyPart = multiPart.getField("file");
            FormDataContentDisposition fdcd = bodyPart.getFormDataContentDisposition();
            System.out.println("filename: " + fdcd.getFileName());
            System.out.println("size: " + fdcd.getSize());
            InputStream body = bodyPart.getValueAs(InputStream.class);
            StringWriter writer = new StringWriter();
            ReaderWriter.writeTo(new InputStreamReader(body), writer);
            return writer.toString();
        }
    }

    @Override
    public ResourceConfig configure() {
        return new ResourceConfig()
                .register(UploadResource.class)
                .register(MultiPartFeature.class)
                .register(new LoggingFilter(Logger.getAnonymousLogger(), true));

    }

    @Test
    public void testProxyClientUpload() throws Exception {
        try (Writer writer = new BufferedWriter(new FileWriter("demo.txt"))) {
            writer.write("Hello World");
        }
        WebTarget target = target("upload").register(MultiPartFeature.class);
        IUploadResource resource = WebResourceFactory.newResource(IUploadResource.class, target);
        FileDataBodyPart filePart = new FileDataBodyPart("file", new File("demo.txt"));
        FormDataMultiPart multiPart = new FormDataMultiPart();
        multiPart.bodyPart(filePart);

        String response = resource.upload(multiPart);
        assertEquals("Hello World", response);
    }
}

- Paul Samsotha