附加上傳、下載自己沒有真正在項目中自己寫過,都是直接調用的框架內現成的方法,所以每次遇到項目框架不提供方法時自己心裏發怯,此處記錄一下項目中自己寫的附件上傳,下載方法,以及下載時前段遇到的坑;
附件上傳
這裏提供的是個接口,前段採用異步的方式進行的上傳;
我們項目的接口書寫方式有些奇怪,和經常用的方法不太一樣;
前段用的是layui的附件上傳組件,寫起來比較方便;
/**
* 附件上傳 單文件上傳
* @param request
* @param response
* @param
*/
@RequestMapping(value = "uploadFile", method = RequestMethod.POST)
public void uploadFile(HttpServletRequest request, HttpServletResponse response){
{
Result result = new Result();
String json = "";
Claims b = JWTUtil.parseJWT(request.getParameter("token"), ConfigLoader.baseSecurity);
String accountName = (String) b.get("accountName");
Accounts account = accountServicesImpl.getEntityBySql("select * from accounts where account_name = '" + accountName + "' and del_flag = 0", null, Accounts.class);
User user = accountServicesImpl.getUserByAccount(account.getId());
File file = null;
try{
// MultipartResolver resolver = new CommonsMultipartResolver(request.getSession().getServletContext());
// MultipartHttpServletRequest multipartRequest = resolver.resolveMultipart(request);
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
MultipartFile multipartFilefile = multipartRequest.getFile("file");
String filename = "";
Long size = 0l;
// MultipartFile multipartFilefile=null;
// Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
// for (Map.Entry<String, MultipartFile> entry : fileMap.entrySet()) {
// multipartFilefile = entry.getValue();
filename = multipartFilefile.getOriginalFilename();
size = multipartFilefile.getSize();
// }
// 從數據字典中獲取上傳路徑
String upconfigPath = "";
List<CategoryAttributes> leiMuAtt = new ArrayList<CategoryAttributes>();
leiMuAtt = ConfCache.attributeConfMap.get("Path_Upload");
if (leiMuAtt != null && leiMuAtt.size() > 0) {
for (CategoryAttributes tr : leiMuAtt) {
CategoryAttributes c = (CategoryAttributes) tr;
if (c.getCategoryAttributesName().equals("上傳公共路徑")) {
upconfigPath = c.getCategoryAttributesValue();
}
}
}
// String downconfigPath = upconfigPath.substring(upconfigPath.lastIndexOf("/") + 1);
// 從數據字典中獲取下載路徑
// String downconfigPath = "";
// List<CategoryAttributes> leiMuAttt=new ArrayList<CategoryAttributes>();
// leiMuAttt=ConfCache.attributeConfMap.get("Path_Download");
// if(leiMuAtt!=null && leiMuAttt.size()>0){
// for (CategoryAttributes tr : leiMuAttt) {
// CategoryAttributes c = (CategoryAttributes)tr;
// downconfigPath=c.getCategoryAttributesValue();
// break;
// }
// }
// 獲取日期時間
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
String date = sdf.format(new Date());
SimpleDateFormat sdft = new SimpleDateFormat("HHmmssSSS");
String timeValue = sdft.format(new Date());
// 上傳到服務器的路徑(數據字典上傳配置+“/attachment/”附件文件夾+日期)
String dir = "";
dir = upconfigPath + "/taskfiles/" + date + "/";
// downconfigPath = downconfigPath + "/taskfiles";
File directory = new File(dir);
// 目錄不存在,創建目錄
if (!directory.exists()) {
directory.mkdir();
}
// 原文件信息
System.out.println(filename);
try {
filename = java.net.URLDecoder.decode(filename, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
System.out.println(filename);
String oldfilename = filename.substring(filename.lastIndexOf("\\") + 1);
String sourcename = oldfilename.substring(0, oldfilename.lastIndexOf(".")); // 文件名
String ofileType = oldfilename.substring(oldfilename.lastIndexOf(".") + 1); // 文件後綴
Long ofileSize = size;
// 新路徑(dir配置路徑+時間戳.格式後綴)
String newfile = dir + timeValue + "." + ofileType;
file = new File(newfile);
Attachment attachment = new Attachment();// 記錄上傳的信息
try {
if (!file.exists()) {
// Accounts account = (Accounts) ss.getAttribute("login_user");
attachment.setFileName(sourcename);
attachment.setDir(dir); // 下載時的相對路徑
attachment.setFileSize(ofileSize);
attachment.setPhysicalName(timeValue + "");
attachment.setCreateTime(new Date());
attachment.setCreateUserId(account.getId());
// attachment.setAttachedTable(attachedTable);
attachment.setStatus(0);
attachment.setFileType(0);
// attachment.setRecordId(recordId);
attachment.setExt(ofileType);
attachment.setUploadPath(dir + timeValue + "." + ofileType);
attachmentServicesImpl.save(attachment);
}
// FileUtils.copyFile((File) files.get(0), file);// 上傳 (複製文件)
FileUtils.copyInputStreamToFile(multipartFilefile.getInputStream(),file);
} catch (IOException e1) {
e1.printStackTrace();
throw new RuntimeException("文件上傳失敗!");
}
StringBuffer sb = new StringBuffer();
sb.append("{");
sb.append("\"code\":");
sb.append(0 + ",");
sb.append("\"msg\":");
sb.append("\"上傳成功!\",");
sb.append("\"data\":");
sb.append(JsonUtil.object2json(attachment));
sb.append("}");
json = sb.toString();
}catch(Exception e){
StringBuffer sb = new StringBuffer();
sb.append("{");
sb.append("\"code\":");
sb.append(1 + ",");
sb.append("\"msg\":");
sb.append("\"上傳失敗!\",");
sb.append("}");
json = sb.toString();
}
this.print(json,response);
}
其中的難點在於如何從HttpServletRequest 中獲取到附件信息,也就是MultipartFile,一開始用的是下面的方法
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
List<MultipartFile> files = multipartRequest.getFiles("files");
但是這個方法會報錯,提示不能直接轉換成MultipartHttpServletRequest ,所以就換成了最上邊的方法轉換,這樣換過之後還是不行,又提示multipartRequest.getFiles("files")內的數量爲0,也就是沒有附件,所以就用以下方法:
MultipartFile multipartFilefile=null;
Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
for (Map.Entry<String, MultipartFile> entry : fileMap.entrySet()) {
multipartFilefile = entry.getValue();
filename = multipartFilefile.getOriginalFilename();
size = multipartFilefile.getSize();
}
上傳路徑是直接到數據字典內取得;
注:上邊兩個是上傳多文件的方法,後期做了修改,代碼中的纔是單文件上傳;
這裏用到了一個工具類org.apache.commons.io包下的FileUtils,裏面有很多操作文件的方法,可以在網上查到,這裏就不列舉了;
這邊從數據字典中獲取的上傳路徑是/u06/upload,所以文件上傳後入庫的路徑也是這個;另外數據庫中還存入和/u06/upload/日期/文件名.houzhui,下載時就直接取用這個字段了,文件上傳成功後,最後上傳到了與我項目workspace同級的/u06/upload文件夾下;
附件下載
先貼上後臺controller代碼:
/**
* 附件下載
* @param request
* @param response
* @param
*/
@RequestMapping(value = "downloadFile")
public void downloadFile(HttpServletRequest request, HttpServletResponse response, String id){
Result result = new Result();
try{
Base base = new Attachment();
base.setId(id);
String ids = request.getParameter("id");
Attachment attachment = (Attachment) attachmentServicesImpl.getBean(base);
String fileName = attachment.getFileName() + "." + attachment.getExt();
// String dir = attachment.getDir();
String path = attachment.getUploadPath();
File sourceFile = new File(path);
if (!sourceFile.exists()) { throw new Exception("您下載的資源已不存在"); }
BufferedInputStream in = null;
ServletOutputStream out = null;
try {
// fileName = URLEncoder.encode(fileName, "UTF-8"); //解決下載文件名亂碼
response.reset();
response.setCharacterEncoding("UTF-8");
// response.setContentType("application/octet-stream");
response.setContentType("application/force-download");
response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
in = new BufferedInputStream(new FileInputStream(sourceFile));
out = response.getOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while ((len = in.read(buffer)) != -1) {
out.write(buffer, 0, len);
}
out.flush();
} catch (Exception e) {
e.printStackTrace();
throw new Exception(fileName + " 下載出錯,若有問題請與管理員聯繫");
} finally {
out.close();
in.close();
}
result.setSuccess(true);
result.setMessage("下載成功");
}catch(Exception e){
e.printStackTrace();
result.setSuccess(false);
result.setMessage("下載失敗!"+e.getMessage());
}
// this.print(result.toString(),response);
}
說一說下載時遇到的坑吧,下載時我是通過點擊<a>標籤,然後觸發一個ajax調用後臺下載的,但是這樣頁面沒有提示任何下載提示,也不報錯,但是response 內有文件的內容,在網上查了一下才知道,附件下載是不能用ajax來搞的,好像ajax返回的是字符類型的結果,瀏覽器沒辦法解析response內的附件,所以必須換方法了,看了別人的方法有用window.href.location的,也有用a標籤內使用download 屬性的,我也試了一下這個屬性,下載的不是原文件,是以download 命名的空文件,然後又在href屬性內直接寫後臺映射地址的,導致頁面跳轉了,也沒有附件下載;最後就用了formdata提交的方式請求,這樣頁面也不會跳轉,還能下載到附件了;
粘上前段代碼;
<div class="layui-upload-list">
<table class="layui-table">
<thead>
<tr><th>文件名</th>
<th>大小</th>
<th>狀態</th>
<th>操作</th>
</tr></thead>
<tbody id="demoList"></tbody>
</table>
</div>
$("#demoList").append('<tr>' +
'<td><a href="#">'+data.list[i].fileName+'.'+data.list[i].ext+'</a></td>' +
'<td>'+((data.list[i].fileSize)/1014).toFixed(1)+'kb</td>' +
'<td><span style="color: #5FB878;">上傳成功</span></td>' +
'<td>' +
'<button class="layui-btn layui-btn-xs demo-reload layui-hide">重傳</button>'+
'<button class="layui-btn layui-btn-xs layui-btn-danger demo-delete-exist">刪除</button>' +
'</td>' +
'<td class="layui-hide">'+data.list[i].id+'</td>' +
'</tr>')
$("#demoList").find("a").on('click',function (e) {
var p_tr = $(this).parent().parent();
//刪除附件數組內的附件id
var tds = p_tr.children();
//找到該附件的主鍵
var id = tds.eq(4).text();
var $eleForm = $("<form method='get'></form>");
$eleForm.attr("action","/CenterChainTaskController/downloadFile");
$(document.body).append($eleForm);
$eleForm.append('<input type="text" name="id" value="'+id+'">')
//提交表單,實現下載
$eleForm.submit();
})