Question

可能重复：
Moving my db to sd card not working

我正在尝试将sqlite文件保存到我的SD卡中。我正在使用此question

中的代码

 try {
    File sd = Environment.getExternalStorageDirectory();
    File data = Environment.getDataDirectory();

    if (sd.canWrite()) {
        String currentDBPath = "\\data\\com.test.mytest\\databases\\test_db";
        String backupDBPath = "test_db";
        File currentDB = new File(data, currentDBPath);
        File backupDB = new File(sd, backupDBPath);

        if (currentDB.exists()) {
            FileChannel src = new FileInputStream(currentDB).getChannel();
            FileChannel dst = new FileOutputStream(backupDB).getChannel();
            dst.transferFrom(src, 0, src.size());
            src.close();
            dst.close();
        }
    }
} catch (Exception e) {
}

这是一个非常高评价的答案，所以我认为它应该非常简单。我在logcat中没有错误。我没有看到任何创建的目录/创建的文件。我的清单中也有“写入外部”权限。

Answer 1

File sd = Environment.getExternalStorageDirectory（）; 文件数据= Environment.getDataDirectory（）;

         if (sd.canWrite()) {
             String currentDBPath = "/data/packagename/databases/DATABASENAME";
             String backupDBPath = "/backup/"+"main.db";
             File currentDB = new File(data, currentDBPath);
             File backupDB = new File(sd, backupDBPath);

             if (currentDB.exists()) {
                 FileChannel src = new FileInputStream(currentDB).getChannel();
                 FileChannel dst = new FileOutputStream(backupDB).getChannel();
                 dst.transferFrom(src, 0, src.size());
                 src.close();
                 dst.close();
             } else {
                 Log.e(TAG, "File does not exist: " + currentDBPath);
             }

Answer 2

不要忘记在清单文件中声明权限

uses-permission android：name =“android.permission.WRITE_EXTERNAL_STORAGE”

试图将SQLite数据库保存到SD卡

2 个答案: