SUPPORT-8381: add file upload service impl and file upload client

backend/src/main/java/ervu/client/fileupload/ErvuFileUploadClient.java

@@ -0,0 +1,10 @@
+package ervu.client.fileupload;
+
+import org.springframework.web.multipart.MultipartFile;
+
+/**
+ * @author Alexandr Shalaginov
+ */
+public interface ErvuFileUploadClient {
+  boolean uploadFile(MultipartFile multipartFile);
+}

backend/src/main/java/ervu/client/fileupload/impl/ErvuFileUploadClientImpl.java

@@ -0,0 +1,51 @@
+package ervu.client.fileupload.impl;
+
+import ervu.client.fileupload.ErvuFileUploadClient;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestClientException;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.multipart.MultipartFile;
+
+/**
+ * @author Alexandr Shalaginov
+ */
+@Component
+public class ErvuFileUploadClientImpl implements ErvuFileUploadClient {
+  @Value("${file.upload.url:#{null}}")
+  private String url;
+  private final RestTemplate restTemplate;
+  private static final Logger logger = LoggerFactory.getLogger(ErvuFileUploadClientImpl.class);
+
+  public ErvuFileUploadClientImpl() {
+    this.restTemplate = new RestTemplate();
+  }
+
+  @Override
+  public boolean uploadFile(MultipartFile multipartFile) {
+    if (this.url == null) {
+      throw new RuntimeException("Property file.upload.url is null");
+    }
+    try {
+      HttpHeaders headers = new HttpHeaders();
+      headers.setContentType(MediaType.MULTIPART_FORM_DATA);
+      MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
+      body.add("file", multipartFile.getResource());
+      HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);
+      ResponseEntity<?> response = this.restTemplate.postForEntity(url, requestEntity, Object.class);
+      return response.getStatusCode().is2xxSuccessful();
+    }
+    catch (RestClientException e) {
+      logger.error("Upload file failed", e);
+      return false;
+    }
+  }
+}

backend/src/main/java/ervu/service/fileupload/impl/ErvuFileUploadV2ServiceImpl.java

@@ -0,0 +1,23 @@
+package ervu.service.fileupload.impl;
+
+import ervu.client.fileupload.ErvuFileUploadClient;
+import ervu.service.fileupload.FileUploadV2Service;
+import org.springframework.stereotype.Service;
+import org.springframework.web.multipart.MultipartFile;
+
+/**
+ * @author Alexandr Shalaginov
+ */
+@Service
+public class ErvuFileUploadV2ServiceImpl implements FileUploadV2Service {
+  private final ErvuFileUploadClient ervuFileUploadClient;
+
+  public ErvuFileUploadV2ServiceImpl(ErvuFileUploadClient ervuFileUploadClient) {
+    this.ervuFileUploadClient = ervuFileUploadClient;
+  }
+
+  @Override
+  public boolean saveFile(MultipartFile multipartFile) {
+    return this.ervuFileUploadClient.uploadFile(multipartFile);
+  }
+}