将数据库文件复制到android中的sdcard

Question

我通过此代码获取我的数据库文件

  File dbFile=getDatabasePath("EdsysEyfsDB.db");
               Log.v("database name checking", dbFile.toString());

我想将此数据库文件复制到SD卡,以便我可以为此做一些操作.但我不能做任何操作.以下代码用于复制到SD卡

         if (dbFile.exists()) {
                       InputStream inStream = new FileInputStream(dbFile);
                       String file = Environment.getExternalStorageDirectory().getPath()
                            +"/" + "database.db";
                       Log.d("file name checking in  dbFilecondition", file);
                       FileOutputStream fs = new FileOutputStream(file);
                       byte[] buffer = new byte[1444];
                       while ((byteread = inStream.read(buffer)) != -1) {
                           bytesum += byteread;
                           fs.write(buffer, 0, byteread);
                       }
                       inStream.close();
                       fs.close();
                   }

但我不会处于这种情况.数据库文件名在LogCat上正常运行.我已经允许读写文件.

Answer 1

试试这个希望这对你有帮助

public void exportDatabse(String databaseName) {
        try {
            File sd = Environment.getExternalStorageDirectory();
            File data = Environment.getDataDirectory();

            if (sd.canWrite()) {
                String currentDBPath = "//data//"+getPackageName()+"//databases//"+databaseName+"";
                String backupDBPath = "backupname.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) {

        }
    }

怎么打电话

exportDatabse("YourDBName");

注意 :

请记住添加写入外部存储的权限 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />,否则sd.canWrite()将为false.