Java JXL和Android i/o权限被拒绝

我正在尝试编写一个应用程序，将数据添加到SD卡上现有的电子表格中

尝试创建可写工作簿时遇到问题：

outputWorkbook=Workbook.createWorkbook（outputWorkbookFile，inputWorkbook）

我在Eclipse中的Logcat中得到错误：

04-05 13:29:54.809:W/System.err（32653）：java.io.FileNotFoundException:/mnt/sdcard/Dev/Spreadsheets/in.xls（权限被拒绝）

我可以读取输入文件并获取单元格的内容，可以实例化可写工作簿或输入工作簿，但不能同时实例化两者

private void doStuff() {
    File directory = Environment.getExternalStorageDirectory();
    inputWorkbookFile = new File(directory + "/Dev/Spreadsheets/in.xls");
    outputWorkbookFile = new File(directory + "/Dev/Spreadsheets/out.xls");

    try {

        // Put data into an array for easier iteration
        double data[];
        data = new double[7];
        data[0] = income;
        data[1] = diesel;
        data[2] = carHire;
        data[3] = radio;
        data[5] = 0;
        data[6] = itemCost;

        inputWorkbook = Workbook.getWorkbook(inputWorkbookFile);
        Log.e("Testing", "Opened workbook");

        if (isExternalStorageAvailable() && isExternalStorageReadable()) {
            Log.e("Testing", "storage readable and available");
            outputWorkbook = Workbook.createWorkbook(outputWorkbookFile,
                    inputWorkbook);
        }

您需要在AndroidManifest标记中声明权限
android.permission.WRITE_EXTERNAL_STORAGE
非常有效。昨晚我确实想到了，但忘了试一下，我的头有点发昏了。谢谢