文件上传---普通文件和url文件

主要用来学习使用common-fileupload.jar和java.net.httpURLConnection

普通文件：

//上传xls文件到临时目录
        if (! ServletFileUpload.isMultipartContent(request)) return;
        DiskFileItemFactory factory = new DiskFileItemFactory();  // 建立factory
        factory.setSizeThreshold(4*1024*1024);  // 设定缓存大小
        ServletFileUpload upload = new ServletFileUpload(factory);
        upload.setFileSizeMax(5120000);//5M

        File srcFile = null;
        try {
            List<FileItem> items = upload.parseRequest(request);
            for (FileItem item : items) {
                if (!item.isFormField()) {
                    String ext = StringUtils.substringAfterLast(item.getName(), ".").toLowerCase();
                    //过滤文件格式
                    if(StringUtils.isEmpty(ext) || !"xls".equalsIgnoreCase(ext)) {
                        System.out.println("Unsupport file type: "+ext);
                        throw new Exception("Unsupport file type: "+ext);
                    }

                    String fileName = Long.toString(Calendar.getInstance().getTimeInMillis())+"."+ext;
                   //临时目录
                   String srcFilePath = "/tmp/" + fileName;
                   srcFile = new File(srcFilePath);
                   if (srcFile.exists()) {
                       continue;
                   }
                   item.write(srcFile);
                }
            }
        }catch (SizeLimitExceededException e){
            e.printStackTrace();
            return;
        }catch (FileUploadException fupEx) {
            fupEx.printStackTrace();
            return;
        }

url文件上传:

System.out.println("Upload url file begins ");
    try {
        String srcURL = request.getParameter("srcURL");
        if(srcURL==null || srcURL.trim().length()<=0) {
            throw new Exception("No url found ");
        }

        String ext = StringUtils.substringAfterLast(srcURL, ".").toLowerCase();
        //初级过滤文件格式
        if(app.getFileExts()!=null && !app.getFileExts().contains(ext)) {
            throw new Exception("Unsupport file type: "+ext);
        }

        String fileName = Long.toString(Calendar.getInstance().getTimeInMillis())+"."+ext;
        String srcFilePath = "/tmp/" + fileName;

        URL urlfile = null;
        HttpURLConnection httpUrl = null;
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        File saveFile = new File(srcFilePath);

        //file wall
        String proxy = "192.168.1.1";
        String port = "8080";
        Properties systemProperties = System.getProperties();
        systemProperties.setProperty("http.proxyHost",proxy);
        systemProperties.setProperty("http.proxyPort",port);

        try{
            urlfile = new URL(srcURL);
            httpUrl = (HttpURLConnection)urlfile.openConnection();

            httpUrl.setConnectTimeout(3000);
            httpUrl.setReadTimeout(60000);

            httpUrl.connect();
            bis = new BufferedInputStream(httpUrl.getInputStream());
        }catch(Exception e)
        {
            e.printStackTrace();
            System.out.println("Souce url connect failed:"+srcURL+" by "+e.getMessage());
            return;
        }

        try{
            int count = 0;
            int size = 0;
            bos = new BufferedOutputStream(new FileOutputStream(saveFile));
            byte[] b = new byte[1024];
            while((count=bis.read(b))!=-1) {
                bos.write(b, 0, count);
                size +=count;
                if(size>=app.getFileSize()) {
                    System.out.println("File size exceeded max limit ");
                    return;
                }
            }
        }catch(Exception e)
        {
            e.printStackTrace();
            System.out.println("Save url file failed:"+srcURL+" by "+e.getMessage());
            return;
        }finally{
            try{
                bos.flush();
                bis.close();
                httpUrl.disconnect();
            }catch(Exception e)
            {
                System.out.println(e.toString());
            }
        }

更多详细关于HttpURLConnection的学习资料请参考：

HttpURLConnection学习

JDK中的URLConnection参数详解