import java.io.*;


public class FileUpload {

    /**
     *
     * @param file 檔案流
     * @param destFilePath 儲存到本地的目錄路徑
     * @return
     */
    public static String upload(MultipartFile file, String destFilePath) {
        InputStream inputStream = null;
        FileOutputStream fileOutputStream 
 
= null;
        try {
            String fileName = file.getOriginalFilename();
            String[] split = fileName.split("\\.");
            inputStream = file.getInputStream();
            // 資料緩衝
            byte[] buffer = new byte[1024 * 1024];
            //讀取到的資料長度
            int len;
            
 
// 輸出的檔案流儲存到本地檔案
            File tempFile = new File(destFilePath);
            if (!tempFile.exists()) {
                tempFile.mkdirs();
            }
            //重新命名
            fileName = Math.random() +"."+ split[split.length-1];
            fileOutputStream = new FileOutputStream(tempFile.getPath() + File.separator + fileName);
            
 
// 開始讀取
            while ((len = inputStream.read(buffer)) != -1) {
                fileOutputStream.write(buffer, 0, len);
            }
            return fileName;
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 完畢，關閉所有連結
            try {
                fileOutputStream.close();
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return "";
    }
}