#13 download files

src/main/java/ru/ulstu/file/service/FileService.java

@@ -13,6 +13,7 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.Date;
 import java.util.List;
+import java.util.UUID;
 import java.util.stream.Collectors;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -39,7 +40,7 @@ public class FileService {
     }
 
     public String uploadToTmpDir(MultipartFile multipartFile) throws IOException {
-        String tmpFileName = String.valueOf(System.currentTimeMillis());
+        String tmpFileName = String.valueOf(System.currentTimeMillis()) + UUID.randomUUID();
         Files.write(getTmpFilePath(tmpFileName), multipartFile.getBytes());
         String meta = multipartFile.getOriginalFilename() + "\n" + multipartFile.getSize();
         Files.write(getTmpFileMetaPath(tmpFileName), meta.getBytes(UTF_8));

src/main/resources/public/js/core.js

@@ -2,6 +2,8 @@
 /* global urlVersions */
 
 var urlFileUpload = "/api/1.0/files/uploadTmpFile";
+var urlFileDownload = "/api/1.0/files/download/";
+var urlFileDownloadTmp = "/api/1.0/files/download-tmp/";
 
 /* exported MessageTypesEnum */
 var MessageTypesEnum = {

src/main/resources/templates/papers/paper.html

@@ -107,8 +107,17 @@
                                                     <span aria-hidden="true"><i class="fa fa-times"/></span>
                                                 </a>
                                             </div>
-                                            <div class="col-10">
+                                            <div class="col-10" th:if="${file.id==null}">
-                                                <div th:text="*{files[__${rowStat.index}__].name}"></div>
+                                                <a th:onclick="|downloadFile('${file.tmpFileName}',null,'${file.name}') |"
+                                                   href="javascript:void(0)"
+                                                   th:text="*{files[__${rowStat.index}__].name}">
+                                                </a>
+                                            </div>
+                                            <div class="col-10" th:unless="${file.id==null}">
+                                                <a th:onclick="|downloadFile(null,${file.id},'${file.name}') |"
+                                                   href="javascript:void(0)"
+                                                   th:text="*{files[__${rowStat.index}__].name}">
+                                                </a>
                                             </div>
                                         </div>
                                     </th:block>
@@ -251,12 +260,43 @@
 
             var nameDiv = $("<div/>")
                 .addClass("col-10")
-                .append($("<div/>").text(fileNames[1]));
+                .append($("<a/>").text(fileNames[1])
+                    .attr("href", 'javascript:void(0)')
+                    .attr("onclick", "downloadFile('" + fileNames[0] + "',null,'" + fileNames[1] + "')"));
             newFileRow.append(nameDiv);
 
             $("#files-list").append(newFileRow);
 
         }
+
+        function downloadFile(tmpName, fileId, downloadName) {
+            let xhr = new XMLHttpRequest();
+            if (fileId != null) xhr.open('GET', urlFileDownload + fileId);
+            if (tmpName != null) xhr.open('GET', urlFileDownloadTmp + tmpName);
+            xhr.responseType = 'blob';
+
+            var formData = new FormData();
+            if (fileId != null) formData.append("file-id", fileId);
+            if (tmpName != null) formData.append("tmp-file-name", tmpName);
+
+            xhr.send(formData);
+
+            xhr.onload = function () {
+                if (this.status == 200) {
+                    console.debug(this.response);
+                    var blob = new Blob([this.response], {type: '*'});
+                    let a = document.createElement("a");
+                    a.style = "display: none";
+                    document.body.appendChild(a);
+                    let url = window.URL.createObjectURL(blob);
+                    a.href = url;
+                    a.download = downloadName;
+                    a.click();
+                    window.URL.revokeObjectURL(url);
+                } else {
+                }
+            }
+        }
     </script>
 </div>