我正在为 Android 实现一个与数据库相关的应用程序。同样的项目也在 iOS 中实现。我可以将此 iOS db 文件用于我的 Android 项目吗？
编辑
以下是我的代码和日志，我在日志中收到错误，但我的应用程序没有崩溃。我唯一关心的是我在哪里做错了。
我的代码是：
public class DataBaseHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.example.test/databases/";
private static String DB_NAME = "testdb.sql";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
private void copyDataBase() throws IOException
{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0)
{
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException
{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close()
{
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db)
{
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
}
public void createDataBase() throws IOException
{
boolean dbExist = checkDataBase();
if(dbExist)
{
//do nothing - database already exist
}
else
{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try
{
copyDataBase();
}
catch (IOException e)
{
throw new Error("Error copying database");
}
}
}
private boolean checkDataBase()
{
SQLiteDatabase checkDB = null;
try
{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
catch(SQLiteException e)
{
//database does't exist yet.
}
if(checkDB != null)
{
checkDB.close();
}
return checkDB != null ? true : false;
}
}
错误日志：
02-14 04:42:01.358: E/SQLiteLog(1552): (14) cannot open file at line 30176 of [00bb9c9ce4]
02-14 04:42:01.378: E/SQLiteLog(1552): (14) os_unix.c:30176: (2) open(/data/data/com.example.test/databases/testdb.sql) -
02-14 04:42:01.508: E/SQLiteDatabase(1552): Failed to open database '/data/data/com.example.test/databases/testdb.sql'.
02-14 04:42:01.508: E/SQLiteDatabase(1552): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at com.example.test.DataBaseHelper.checkDataBase(DataBaseHelper.java:126)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at com.example.test.DataBaseHelper.createDataBase(DataBaseHelper.java:90)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at com.example.test.LoginActivity.onCreate(LoginActivity.java:59)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.Activity.performCreate(Activity.java:5104)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.ActivityThread.access$600(ActivityThread.java:141)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.os.Handler.dispatchMessage(Handler.java:99)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.os.Looper.loop(Looper.java:137)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at android.app.ActivityThread.main(ActivityThread.java:5039)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at java.lang.reflect.Method.invokeNative(Native Method)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at java.lang.reflect.Method.invoke(Method.java:511)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
02-14 04:42:01.508: E/SQLiteDatabase(1552): at dalvik.system.NativeStart.main(Native Method)