[#2523]fix problem when client api do not provide file parameter

common/common-rest/src/main/java/org/apache/servicecomb/common/rest/codec/param/RestClientRequestImpl.java

@@ -32,7 +32,6 @@
 import javax.servlet.http.Part;
 import javax.ws.rs.core.MediaType;
 
-import com.google.common.annotations.VisibleForTesting;
 import org.apache.servicecomb.common.rest.codec.RestClientRequest;
 import org.apache.servicecomb.common.rest.codec.RestObjectMapperFactory;
 import org.apache.servicecomb.foundation.common.utils.PartUtils;
@@ -44,6 +43,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.Multimap;
 
@@ -63,7 +63,7 @@ public class RestClientRequestImpl implements RestClientRequest {
   protected AsyncResponse asyncResp;
 
   @VisibleForTesting
-  final Multimap<String, Part> uploads = ArrayListMultimap.create();
+  protected Multimap<String, Part> uploads;
 
   protected HttpClientRequest request;
 
@@ -101,8 +101,11 @@ public Buffer getBodyBuffer() throws Exception {
   @Override
   @SuppressWarnings("unchecked")
   public void attach(String name, Object partOrList) {
+    if (uploads == null) {
+      uploads = ArrayListMultimap.create();
+    }
+
     if (null == partOrList) {
-      LOGGER.debug("null file is ignored, file name = [{}]", name);
       return;
     }
 
@@ -126,7 +129,7 @@ public void attach(String name, Object partOrList) {
   public Future<Void> end() {
     writeCookies();
 
-    if (!uploads.isEmpty()) {
+    if (uploads != null) {
       return doEndWithUpload();
     }
 

common/common-rest/src/test/java/org/apache/servicecomb/common/rest/codec/param/TestRestClientRequestImpl.java

@@ -161,6 +161,7 @@ public void doEndWithUploadForJre8() {
     try (MockedStatic<UUID> mockedStatic = Mockito.mockStatic(UUID.class)) {
       mockedStatic.when(UUID::randomUUID).thenReturn(uuid);
       RestClientRequestImpl restClientRequest = new RestClientRequestImpl(request, context, null);
+      restClientRequest.attach("file", null);
       restClientRequest.doEndWithUpload();
 
       Assertions.assertEquals("multipart/form-data; charset=UTF-8; boundary=boundarynull-null-null-null-null",
@@ -181,6 +182,7 @@ public void doEndWithUploadAfterJre8() {
     try (MockedStatic<UUID> mockedStatic = Mockito.mockStatic(UUID.class)) {
       mockedStatic.when(UUID::randomUUID).thenReturn(uuid);
       RestClientRequestImpl restClientRequest = new RestClientRequestImpl(request, context, null);
+      restClientRequest.attach("file", null);
       restClientRequest.doEndWithUpload();
 
       Assertions.assertEquals("multipart/form-data; charset=UTF-8; boundary=boundary00000000-0000-0000-0000-000000000000",

demo/demo-spring-boot-transport/demo-spring-boot-springmvc-client/src/main/java/org/apache/servicecomb/springboot/springmvc/client/UploadDownloadSchemaTest.java

@@ -0,0 +1,69 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.servicecomb.springboot.springmvc.client;
+
+import java.io.File;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.servicecomb.demo.CategorizedTestCase;
+import org.apache.servicecomb.demo.TestMgr;
+import org.apache.servicecomb.provider.springmvc.reference.RestTemplateBuilder;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestOperations;
+
+@Component
+public class UploadDownloadSchemaTest implements CategorizedTestCase {
+  RestOperations restOperations = RestTemplateBuilder.create();
+
+  @Override
+  public void testRestTransport() throws Exception {
+    testEmptyFileUploadWork();
+    testNonEmptyFileUploadWorkd();
+  }
+
+  private void testNonEmptyFileUploadWorkd() throws Exception {
+    String file2Content = " bonjour";
+    File someFile = File.createTempFile("upload2", ".txt");
+    FileUtils.writeStringToFile(someFile, file2Content, StandardCharsets.UTF_8, false);
+    HttpHeaders headers = new HttpHeaders();
+    headers.setContentType(MediaType.MULTIPART_FORM_DATA);
+    Map<String, Object> params = new HashMap<>();
+    params.put("name", "test");
+    params.put("file", someFile);
+    HttpEntity<Map<String, Object>> entity = new HttpEntity<>(params, headers);
+    String url = "servicecomb://springmvc/up/down/upload";
+    String result = restOperations.postForObject(url, entity, String.class);
+    TestMgr.check("test; bonjour", result);
+  }
+
+  private void testEmptyFileUploadWork() {
+    HttpHeaders headers = new HttpHeaders();
+    headers.setContentType(MediaType.MULTIPART_FORM_DATA);
+    Map<String, Object> params = new HashMap<>();
+    params.put("name", "test");
+    HttpEntity<Map<String, Object>> entity = new HttpEntity<>(params, headers);
+    String url = "servicecomb://springmvc/up/down/upload";
+    String result = restOperations.postForObject(url, entity, String.class);
+    TestMgr.check("test;", result);
+  }
+}

demo/demo-spring-boot-transport/demo-spring-boot-springmvc-server/src/main/java/org/apache/servicecomb/springboot/springmvc/server/UploadDownloadSchema.java

@@ -0,0 +1,48 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.servicecomb.springboot.springmvc.server;
+
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+
+import javax.ws.rs.core.MediaType;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.servicecomb.provider.rest.common.RestSchema;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestPart;
+import org.springframework.web.multipart.MultipartFile;
+
+
+@RestSchema(schemaId = "UploadDownloadSchema")
+@RequestMapping(path = "/up/down")
+public class UploadDownloadSchema {
+  @PostMapping(path = "/upload", consumes = MediaType.MULTIPART_FORM_DATA)
+  public String fileUpload(@RequestPart MultipartFile file, @RequestPart(value = "name") String name) throws Exception {
+    StringBuilder result = new StringBuilder();
+    result.append(name).append(";");
+    if (file == null || file.isEmpty()) {
+      return result.toString();
+    }
+    try (InputStream is = file.getInputStream()) {
+      result.append(IOUtils.toString(is, StandardCharsets.UTF_8));
+    }
+    return result.toString();
+  }
+}

demo/demo-springmvc/springmvc-server/src/main/java/org/apache/servicecomb/demo/springmvc/server/ProducerTestsAfterBootup.java

@@ -93,7 +93,7 @@ public void testRegisteredBasePath() {
     if (DynamicPropertyFactory.getInstance().getBooleanProperty("servicecomb.test.vert.transport", true).get()) {
       TestMgr.check(22, RegistrationManager.INSTANCE.getMicroservice().getPaths().size());
     } else {
-      TestMgr.check(23, RegistrationManager.INSTANCE.getMicroservice().getPaths().size());
+      TestMgr.check(24, RegistrationManager.INSTANCE.getMicroservice().getPaths().size());
     }
   }
 

transports/transport-rest/transport-rest-client/src/main/java/org/apache/servicecomb/transport/rest/client/RestClientRequestParametersImpl.java

@@ -108,15 +108,14 @@ public Multimap<String, Part> getUploads() {
   @SuppressWarnings("unchecked")
   @Override
   public void attach(String name, Object partOrList) {
-    if (partOrList == null) {
-      LOGGER.debug("null file is ignored, file name = [{}]", name);
-      return;
-    }
-
     if (uploads == null) {
       uploads = ArrayListMultimap.create();
     }
 
+    if (partOrList == null) {
+      return;
+    }
+
     if (partOrList.getClass().isArray()) {
       for (Object part : (Object[]) partOrList) {
         uploads.put(name, PartUtils.getSinglePart(name, part));