使用springboot進行文件上傳和下載
##文件下載功能的實現思路:
1.獲取要下載的文件的絕對路徑
2.獲取要下載的文件名
3.設置content-disposition響應頭控制瀏覽器以下載的形式打開文件
4.獲取要下載的文件輸入流
5.創建數據緩衝區//緩衝區解釋見下文
6.通過response對象獲取OutputStream流
7.將FileInputStream流寫入到buffer緩衝區
單文件上傳
// 單文件上傳
@RequestMapping(value = "/upload")
@ResponseBody
public String upload(@RequestParam("file") MultipartFile file) {
try {
if (file.isEmpty()) {
return "文件爲空";
}
// 獲取文件名
String fileName = file.getOriginalFilename();
logger.info("上傳的文件名爲:" + fileName);
// 獲取文件的後綴名
String suffixName = fileName.substring(fileName.lastIndexOf("."));
logger.info("文件的後綴名爲:" + suffixName);
// 設置文件存儲路徑
String filePath = "D://aim//";
String path = filePath + fileName + suffixName;
File dest = new File(path);
// 檢測是否存在目錄
if (!dest.getParentFile().exists()) {
dest.getParentFile().mkdirs();// 新建文件夾
}
file.transferTo(dest);// 文件寫入
return "上傳成功";
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return "上傳失敗";
}
多文件上傳
//多文件上傳
@RequestMapping(value = "/uploadMore", method = RequestMethod.POST)
@ResponseBody
public String handleFileUpload(HttpServletRequest request) {
List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
MultipartFile file = null;
BufferedOutputStream stream = null;
for (int i = 0; i < files.size(); ++i) {
file = files.get(i);
String filePath = "D://aim//";
if (!file.isEmpty()) {
try {
byte[] bytes = file.getBytes();
stream = new BufferedOutputStream(new FileOutputStream(
new File(filePath + file.getOriginalFilename())));//設置文件路徑及名字
stream.write(bytes);// 寫入
stream.close();
} catch (Exception e) {
stream = null;
return "第 " + i + " 個文件上傳失敗 ==> "
+ e.getMessage();
}
} else {
return "第 " + i
+ " 個文件上傳失敗因爲文件爲空";
}
}
return "上傳成功";
}
文件下載
//文件下載相關代碼
@RequestMapping("/download")
public String downloadFile(HttpServletRequest request, HttpServletResponse response) {
String fileName = "aim_test.txt";// 設置文件名,根據業務需要替換成要下載的文件名
if (fileName != null) {
//設置文件路徑
String realPath = "D://aim//"
File file = new File(realPath , fileName);
if (file.exists()) {
response.setContentType("application/force-download");// 設置強制下載不打開
response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);// 設置文件名
byte[] buffer = new byte[1024];
FileInputStream fis = null;
BufferedInputStream bis = null;
try {
fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
OutputStream os = response.getOutputStream();
int i = bis.read(buffer);
while (i != -1) {
os.write(buffer, 0, i);
i = bis.read(buffer);
}
System.out.println("success");
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
return null;
}
表單頁面
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<title>Getting Started: Serving Web Content</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<p>Get your greeting <a href="/greeting">here</a></p>
<form action="/upload" method="POST" enctype="multipart/form-data">
文件:<input type="file" name="test"/>
<input type="submit" />
</form>
<a href="/download">下載test</a>
<p>多文件上傳</p>
<form method="POST" enctype="multipart/form-data" action="/batch/upload">
<p>文件1:<input type="file" name="file" /></p>
<p>文件2:<input type="file" name="file" /></p>
<p><input type="submit" value="上傳" /></p>
</form>
</html>
如圖所示
ps:如果下載的文件出現亂碼問題
希望對你有所幫助!