拷贝数据库文件在android的SD卡 [英] copy database file to sdcard in android

问题描述

我对这个code让我的数据库文件

I am getting my database file by this code

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

我要复制这个数据库文件到SD卡，所以我可以做一些操作的。但我不能做任何操作。下面code使用拷贝到SD卡

I want to copy this database file to sdcard so I can do some operation for that. But I can't do any operation on that. The below code is using for copy to sd card

         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();
                   }

不过，我不打算在此condition.The数据库文件名上LogCat中来了正常。我已经给权限读取和写入文件。

But I am not going in this condition.The database file name is coming properly on LogCat. I already give permission for Read and Write file.

推荐答案

试试这个希望这可以帮助你。

Try this hope this helps you

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) {

        }
    }

如何调用

exportDatabse("YourDBName");

注意：

记住要添加权限写入到外部存储与 ＆LT;使用-权限的Andr​​oid：名称=android.permission.WRITE_EXTERNAL_STORAG​​E/＆GT; ，否则sd.canWrite（）将是错误的。

Remember to add permission to write to external storage with <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />, otherwise sd.canWrite() will be false.

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