feat: add support for multipart downloading of a translated file to Files API

smartling-files-api/src/main/java/com/smartling/api/files/v2/FilesApi.java

@@ -20,6 +20,7 @@
 import com.smartling.api.v2.client.exception.server.DetailedErrorMessage;
 import com.smartling.api.v2.response.EmptyData;
 import com.smartling.api.v2.response.ListResponse;
+import com.smartling.api.files.v2.resteasy.ext.TranslatedFileMultipart;
 import org.jboss.resteasy.annotations.providers.multipart.MultipartForm;
 
 import javax.ws.rs.BeanParam;
@@ -36,6 +37,7 @@
 import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
 import static javax.ws.rs.core.MediaType.MULTIPART_FORM_DATA;
 import static javax.ws.rs.core.MediaType.WILDCARD;
+import static org.jboss.resteasy.plugins.providers.multipart.MultipartConstants.MULTIPART_MIXED;
 
 @Produces(APPLICATION_JSON)
 @Consumes(APPLICATION_JSON)
@@ -66,6 +68,11 @@ public interface FilesApi
     @Produces(WILDCARD)
     InputStream downloadTranslatedFile(@PathParam("projectId") String projectId, @PathParam("localeId") String localeId, @BeanParam DownloadTranslationPTO downloadTranslationPTO);
 
+    @GET
+    @Path("/projects/{projectId}/locales/{localeId}/file")
+    @Produces(MULTIPART_MIXED)
+    TranslatedFileMultipart downloadTranslatedFileMultipart(@PathParam("projectId") String projectId, @PathParam("localeId") String localeId, @BeanParam DownloadTranslationPTO downloadTranslationPTO);
+
     @GET
     @Path("/projects/{projectId}/locales/all/file/zip")
     @Produces(WILDCARD)

smartling-files-api/src/main/java/com/smartling/api/files/v2/FilesApiFactory.java

@@ -1,11 +1,14 @@
 package com.smartling.api.files.v2;
 
 import com.smartling.api.files.v2.exceptions.FilesApiExceptionMapper;
+import com.smartling.api.files.v2.resteasy.ext.TranslatedFileMultipartReader;
 import com.smartling.api.v2.client.AbstractApiFactory;
 import com.smartling.api.v2.client.ClientConfiguration;
 import com.smartling.api.v2.client.ClientFactory;
 import com.smartling.api.v2.client.DefaultClientConfiguration;
 import com.smartling.api.v2.client.auth.AuthorizationRequestFilter;
+import org.jboss.resteasy.client.jaxrs.internal.ResteasyClientBuilderImpl;
+import org.jboss.resteasy.spi.ResteasyProviderFactory;
 
 public class FilesApiFactory extends AbstractApiFactory<FilesApi>
 {
@@ -28,13 +31,18 @@ protected Class<FilesApi> getApiClass()
     @Override
     public FilesApi buildApi(final AuthorizationRequestFilter authFilter, ClientConfiguration config)
     {
+        ResteasyProviderFactory resteasyProviderFactory = config.getResteasyProviderFactory();
+        if (null == resteasyProviderFactory)
+            resteasyProviderFactory = new ResteasyClientBuilderImpl().getProviderFactory();
+        resteasyProviderFactory.register(TranslatedFileMultipartReader.class);
+
         ClientConfiguration filesConfig = DefaultClientConfiguration.builder()
             .baseUrl(config.getBaseUrl())
             .clientRequestFilters(config.getClientRequestFilters())
             .clientResponseFilters(config.getClientResponseFilters())
             .libNameVersionHolder(config.getLibNameVersionHolder())
             .httpClientConfiguration(config.getHttpClientConfiguration())
-            .resteasyProviderFactory(config.getResteasyProviderFactory())
+            .resteasyProviderFactory(resteasyProviderFactory)
             .exceptionMapper(new FilesApiExceptionMapper())
             .build();
 

smartling-files-api/src/main/java/com/smartling/api/files/v2/resteasy/ext/TranslatedFileMetadata.java

@@ -0,0 +1,10 @@
+package com.smartling.api.files.v2.resteasy.ext;
+
+import lombok.Data;
+
+@Data
+public class TranslatedFileMetadata
+{
+    // Now we leave the class empty and will use it as an end marker for the file body only.
+    // In the future we will expand this object with additional metadata associated with the downloaded file.
+}

smartling-files-api/src/main/java/com/smartling/api/files/v2/resteasy/ext/TranslatedFileMultipart.java

@@ -0,0 +1,29 @@
+package com.smartling.api.files.v2.resteasy.ext;
+
+import lombok.Getter;
+import org.apache.commons.io.IOUtils;
+import org.jboss.resteasy.plugins.providers.multipart.MultipartInput;
+
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.MultivaluedMap;
+import java.io.InputStream;
+
+public class TranslatedFileMultipart
+{
+    @Getter
+    InputStream fileBody;
+    @Getter
+    MultivaluedMap<String, String> fileHeaders;
+    @Getter
+    MediaType fileMediaType;
+    @Getter
+    TranslatedFileMetadata translatedFileMetadata;
+    MultipartInput multipartInput;
+
+    public void close()
+    {
+        IOUtils.closeQuietly(fileBody);
+        if (null != multipartInput)
+            multipartInput.close();
+    }
+}

smartling-files-api/src/main/java/com/smartling/api/files/v2/resteasy/ext/TranslatedFileMultipartReader.java

@@ -0,0 +1,72 @@
+package com.smartling.api.files.v2.resteasy.ext;
+
+import org.apache.commons.lang3.StringUtils;
+import org.jboss.resteasy.plugins.providers.multipart.InputPart;
+import org.jboss.resteasy.plugins.providers.multipart.MultipartInputImpl;
+import org.jboss.resteasy.plugins.providers.multipart.i18n.Messages;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.ext.MessageBodyReader;
+import javax.ws.rs.ext.Provider;
+import javax.ws.rs.ext.Providers;
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
+import static java.lang.String.format;
+import static org.jboss.resteasy.plugins.providers.multipart.MultipartConstants.MULTIPART_MIXED;
+
+@Provider
+@Consumes(MULTIPART_MIXED)
+public class TranslatedFileMultipartReader implements MessageBodyReader<TranslatedFileMultipart>
+{
+    private static final String BOUNDARY_PARAMETER = "boundary";
+
+    protected @Context Providers workers;
+
+    @Override
+    public boolean isReadable(Class<?> clazz, Type type, Annotation[] annotations, MediaType mediaType)
+    {
+        return type.equals(TranslatedFileMultipart.class);
+    }
+
+    @Override
+    public TranslatedFileMultipart readFrom(Class<TranslatedFileMultipart> clazz, Type type, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, String> multivaluedMap, InputStream inputStream) throws IOException, WebApplicationException
+    {
+        final String boundary = mediaType.getParameters().get(BOUNDARY_PARAMETER);
+        if (null == boundary)
+            throw new IOException(Messages.MESSAGES.unableToGetBoundary());
+        final MultipartInputImpl multipartInput = new MultipartInputImpl(mediaType, workers);
+        multipartInput.parse(inputStream);
+
+        if (multipartInput.getParts().size() != 2)
+            throw new IOException(format("The response contains unexpected number of parts (%d). Two parts are expected. The first one is file's body, the second one is metadata object.", multipartInput.getParts().size()));
+
+        final InputPart filePart = multipartInput.getParts().get(0);
+        final InputPart metadataPart = multipartInput.getParts().get(1);
+
+        final TranslatedFileMultipart translatedFileMultipart = new TranslatedFileMultipart();
+        translatedFileMultipart.multipartInput = multipartInput;
+        translatedFileMultipart.fileBody = filePart.getBody(InputStream.class, null);
+        translatedFileMultipart.fileHeaders = filePart.getHeaders();
+        translatedFileMultipart.fileMediaType = filePart.getMediaType();
+
+        final MediaType metadataPartMediaType = metadataPart.getMediaType();
+        if (null == metadataPartMediaType)
+            throw new IOException("Missing content type of metadata part.");
+
+        if (!StringUtils.equalsIgnoreCase(MediaType.APPLICATION_JSON_TYPE.getType(), metadataPartMediaType.getType()) || !StringUtils.equalsIgnoreCase(MediaType.APPLICATION_JSON_TYPE.getSubtype(), metadataPartMediaType.getSubtype()))
+            throw new IOException(format("Unexpected content type of metadata part (%s). Expected (%s) metadata part.", metadataPart.getMediaType(), MediaType.APPLICATION_JSON_TYPE));
+
+        translatedFileMultipart.translatedFileMetadata = metadataPart.getBody(TranslatedFileMetadata.class, TranslatedFileMetadata.class);
+        if (null == translatedFileMultipart.translatedFileMetadata)
+            throw new IOException("Cannot construct metadata json object.");
+
+        return translatedFileMultipart;
+    }
+}

smartling-files-api/src/test/java/com/smartling/api/files/v2/FilesApiIntTest.java

@@ -7,6 +7,7 @@
 import com.smartling.api.files.v2.pto.GetFileLastModifiedPTO;
 import com.smartling.api.files.v2.pto.UploadFilePTO;
 import com.smartling.api.files.v2.pto.UploadFileResponse;
+import com.smartling.api.files.v2.resteasy.ext.TranslatedFileMultipart;
 import com.smartling.api.v2.client.ClientConfiguration;
 import com.smartling.api.v2.client.DefaultClientConfiguration;
 import com.smartling.api.v2.client.auth.BearerAuthStaticTokenFilter;
@@ -87,6 +88,44 @@ public void shouldRetrieveTranslation() throws Exception
         assertEquals(IOUtils.toString(response, UTF_8), rawBody);
     }
 
+    @Test
+    public void shouldRetrieveTranslationMultipart() throws Exception
+    {
+        final String boundary = UUID.randomUUID().toString();
+        final String responseBody = "--" + boundary + "\r\n"
+            + "Content-Type: application/octet-stream; charset=UTF-8\r\n"
+            + "Content-Disposition: attachment; filename=\"myfile.properties\";\r\n"
+            + "\r\n"
+            + "key1=value1\nkey2=value2\r\n"
+            + "--" + boundary + "\r\n"
+            + "Content-Type: application/json; charset=UTF-8\r\n"
+            + "\r\n"
+            + "{\"key\":\"value\"}\r\n"
+            + "--" + boundary + "--";
+
+        smartlingApi.stubFor(get(urlPathMatching("/files-api/v2/projects/.+/locales/zh-CN/file.*"))
+            .withQueryParam("fileUri", equalTo(FILE_URI))
+            .withQueryParam("retrievalType", equalTo(PUBLISHED.toString()))
+            .willReturn(aResponse()
+                .withHeader("Content-Type", "multipart/mixed; boundary=" + boundary)
+                .withBody(responseBody)
+            )
+        );
+
+        TranslatedFileMultipart response = filesApi.downloadTranslatedFileMultipart(
+            PROJECT_ID,
+            "zh-CN",
+            DownloadTranslationPTO.builder()
+                .fileUri(FILE_URI)
+                .retrievalType(PUBLISHED)
+                .build()
+        );
+
+        InputStream stream = response.getFileBody();
+
+        assertEquals(IOUtils.toString(stream, UTF_8), "key1=value1\nkey2=value2");
+    }
+
     @Test
     public void shouldUploadFile() throws Exception
     {