導入/導出到Android的SQLite數據庫

Question

我見過一些關於如何導入和導出數據庫在Android的帖子，我發現這些代碼，但我似乎無法使它的工作。我得到錯誤java.io.filenotfoundexception/storage/sdcard0/BackupFolder/DatabaseName：打開失敗的ENOENT（沒有這樣的文件或目錄）。香港專業教育學院改變了一些東西，但我仍然沒有得到文件中發現異常

這裏是我的出口：

private void exportDB() { 
     try { 
      db.open(); 
      File newFile = new File("/sdcard/myexport"); 
      InputStream input = new FileInputStream(
      "/data/data/com.example.mycarfuel/data 

bases/MyDatabase"); 

       OutputStream output = new FileOutputStream(newFile); 
       byte[] buffer = new byte[1024]; 
       int length; 
       while ((length = input.read(buffer)) > 0) { 
        output.write(buffer, 0, length); 
       } 
       output.flush(); 
       output.close(); 
       input.close(); 
       db.close(); 

      } catch (FileNotFoundException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
      } catch (IOException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
} 

和我的導入：

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

      if (sd.canWrite()) { 
       String currentDBPath = "//data//" + "PackageName" 
         + "//databases//" + "DatabaseName"; 
        String backupDBPath = "/BackupFolder/DatabaseName 

"; 
       File backupDB = new File(data, currentDBPath); 
       File currentDB = 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(); 
    } 
} 

Answer 1

SQLite數據庫到我們的本地文件系統 -

函數聲明-

 try { 
      backupDatabase(); 
     } catch (IOException e1) { 
      // TODO Auto-generated catch block 
      e1.printStackTrace(); 
     } 

功能defined-

public static void backupDatabase() throws IOException { 
     //Open your local db as the input stream 
     String inFileName = "/data/data/com.myapp.main/databases/MYDB"; 
     File dbFile = new File(inFileName); 
     FileInputStream fis = new FileInputStream(dbFile); 

     String outFileName = Environment.getExternalStorageDirectory()+"/MYDB"; 
     //Open the empty db as the output stream 
     OutputStream output = new FileOutputStream(outFileName); 
     //transfer bytes from the inputfile to the outputfile 
     byte[] buffer = new byte[1024]; 
     int length; 
     while ((length = fis.read(buffer))>0){ 
      output.write(buffer, 0, length); 
     } 
     //Close the streams 
     output.flush(); 
     output.close(); 
     fis.close(); 
    } 

Answer 2

以上接受的答案，因爲數據庫的路徑是不同不會對Android版本工作在上面6。

請檢查以下代碼。它將適用於所有設備。

public static boolean exportDB(Context context) { 
    String DATABASE_NAME = "my.db"; 
    String databasePath = context.getDatabasePath(DATABASE_NAME).getPath(); 
    String inFileName = databasePath; 
    try { 
     File dbFile = new File(inFileName); 
     FileInputStream fis = new FileInputStream(dbFile); 

     String outFileName = Environment.getExternalStorageDirectory() + "/" + DATABASE_NAME; 

     OutputStream output = new FileOutputStream(outFileName); 

     byte[] buffer = new byte[1024]; 
     int length; 
     while ((length = fis.read(buffer)) > 0) { 
      output.write(buffer, 0, length); 
     } 
     //Close the streams 
     output.flush(); 
     output.close(); 
     fis.close(); 
     return true; 
    } catch (Exception e) { 
     return false; 
    } 
}