Question

我正在开发一个黑莓应用，我从网络服务获得了一个pdf-url。我需要使用该URL下载该PDF并将其保存到我的SD卡中。

请告诉我，是否有可能。

Answer 1

我很抱歉回复很晚，我在这项任务中取得了成功。我知道这不是一项“努力工作”，但对我来说这是一个教训。我使用以下线程代码完成此任务。

private class DownloadCombiner extends Thread {
        private String remoteName;
        private String localName;
        private int connection;
        private int chunksize;
        public DownloadCombiner(String remoteName, 
                String localName, int connection, int chunksize) {
            this.remoteName = remoteName;
            this.localName = localName;
            this.connection = connection;
            this.chunksize = chunksize;
        }
        public void run() {
            try {
                int chunkIndex = 0;
                int totalSize = 0;
                /*
                 * File connection
                 */
                 FileConnection file =(FileConnection)Connector.open(localName);
                 if (!file.exists()) {
                     file.create();
                 }
                 file.setWritable(true);
                 OutputStream out = file.openOutputStream();
                 /*
                  * HTTP Connections
                  */
                 String currentFile = remoteName + connectionType();
                 //log("Full URL: " + currentFile);
                 HttpConnection conn;
                 InputStream in;
                 int rangeStart = 0;
                 int rangeEnd = 0;
                 while (true) {
                     //  log("Opening Chunk: " + chunkIndex);
                     conn = (HttpConnection) Connector.open(currentFile, 
                             Connector.READ_WRITE, true);
                     rangeStart = chunkIndex * chunksize;
                     rangeEnd = rangeStart + chunksize - 1;
                     // log("Requesting Range: " + rangeStart + 
                     //      "-" + rangeEnd);
                     conn.setRequestProperty("Range", "bytes=" +
                             rangeStart + "-" + rangeEnd);
                     int responseCode = conn.getResponseCode();
                     if (responseCode != 200 && responseCode != 206)
                     {
                         // log("Response Code = " + conn.getResponseCode());
                         break;
                     }
                     // log("Retreived Range: " + conn.getHeaderField("Content-Range"));
                     in = conn.openInputStream();
                     int length = -1;
                     byte[] readBlock = new byte[256];
                     int fileSize = 0;
                     while ((length = in.read(readBlock)) != -1) {
                         out.write(readBlock, 0, length);
                         fileSize += length;
                         Thread.yield(); // Try not to get cut off
                     }
                     totalSize += fileSize;
                     // log("Chunk Downloaded: " + fileSize + " Bytes");
                     chunkIndex++; // index (range) increase
                     in.close();
                     conn.close();
                     in = null;
                     conn = null;
                     /*
                      * Pause to allow connections to close and other Threads
                      * to run.
                      */
                     Thread.sleep(1000);
                 }
                 // log("Full file downloaded: " + totalSize + " Bytes");
                 out.close();
                 file.close();
                 // log("Wrote file to local storage");
            } catch (Exception e) {
                System.out.println(e.toString());
            }
        }
        private String connectionType() {
            switch (connection) {
            case 1:
                return ";deviceside=false";
            case 2:
                return ";deviceside=true;interface=wifi";
            default:
                return ";deviceside=true";
            }
        }
    }

从黑莓手机网站下载pdf文件？

1 个答案: