我正在使用以下代码在Stack Overflow上发布并为我的目的进行了修改:
try {
File sd = Environment.getExternalStorageDirectory();
File data = Environment.getDataDirectory();
if (sd.canWrite()) {
String currentDBPath = "//data//"+ "com.exercise.AndroidSQLite" +"//databases//"+"MY_DATABASE";
String backupDBPath = "/temp/MY_DATABASE";
File currentDB = new File(data, currentDBPath);
File backupDB = new File(sd, backupDBPath);
FileChannel src = new FileInputStream(currentDB).getChannel();
FileChannel dst = new FileOutputStream(backupDB).getChannel();
dst.transferFrom(src, 0, src.size());
src.close();
dst.close();
Toast.makeText(getBaseContext(), backupDB.toString(), Toast.LENGTH_LONG).show();
}
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.toString(), Toast.LENGTH_LONG).show();
}
}
因此,当我尝试访问它时出现的错误是:
java.io.FileNotFoundException: /data/data/com.exercise.AndroidSQLite/databases/MY_DATABASE: open failed: EACCES (Permission Denied)
我正在尝试复制此文件而不会使我的平板电脑生根。写入外部存储目录权限在应用程序中设置;我无法绕过这个错误。非常感谢帮助解决这个问题,这让我很生气
答案 0 :(得分:4)
我在我的Android应用程序中备份我的数据库,它工作正常。如果您是数据库文件的所有者,则只能访问数据库文件,这意味着您的应用程序已创建它。
我认为你的道路是错的,我在我的应用程序中有这个:
private static final String DATABASE_NAME = "my.db.name";
public File getBackupDatabaseFile() {
File dir = new File(getStorageBaseDirectory().getAbsolutePath() + "/backup");
if (!dir.exists()) {
dir.mkdirs();
}
return new File(dir, DATABASE_NAME);
}
public final boolean backupDatabase() {
File from = mContext.getDatabasePath(DATABASE_NAME);
File to = this.getBackupDatabaseFile();
try {
FileUtils.copyFile(from, to);
return true;
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e(TAG, "Error backuping up database: " + e.getMessage(), e);
}
return false;
}
FileUtils.copyFIle是这样的:
public static void copyFile(File src, File dst) throws IOException {
FileInputStream in = new FileInputStream(src);
FileOutputStream out = new FileOutputStream(dst);
FileChannel fromChannel = null, toChannel = null;
try {
fromChannel = in.getChannel();
toChannel = out.getChannel();
fromChannel.transferTo(0, fromChannel.size(), toChannel);
} finally {
if (fromChannel != null)
fromChannel.close();
if (toChannel != null)
toChannel.close();
}
}
答案 1 :(得分:2)
当您可能真的想将它用作变量时,您正在使用“MY_DATABASE”......
从中删除引号,看看是否无法解决您的问题。