java - Sqlite数据库不会复制到真实设备的sd卡中

Question

我通过这种方法将我的数据库(sqllite)复制到SD卡:

String currentDBPath =
                "\\data\\com.powergroupbd.tripmileage\\databases\\tripmileagedatabase";
                 String backupDBPath = "tripmileagedatabase";
                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();

这在模拟器中工作正常，但当我将其安装在真实设备中时，它不会显示 SD 卡中的任何文件。我缺少什么？

Answer 1

数据库的路径从/data/data/开始。请注意，路径分隔符是正斜杠，而不是反斜杠。因此，将您的代码更改为:

String currentDBPath =
            "/data/data/com.powergroupbd.tripmileage/databases/tripmileagedatabase";
             String backupDBPath = "tripmileagedatabase";
            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();