我有一个有效的DataBaseHelper，在其中我取消了两个警告并忽略了一个建议。完整的应用程序运行良好，但偶尔会收到错误通知。堆栈跟踪几乎总是指向链接到数据库的错误，并且通常在d / b版本更新之后。进行全新安装时，似乎没有问题。
被忽略的建议是在行中突出显示“ / data / data /”：
DB_PATH =“ / data / data /” + context.getPackageName（）+“ / databases /”;
尽管将其替换为不会引发任何警报：DB_PATH = myContext.getFilesDir（）。getPath（）;该应用程序在运行时找不到数据库详细信息。 （注意：软件建议使用Context.getFilesDir（）而不是myContext.getFilesDir（）'，但这也不起作用。
在标记为~~~~的四行中显示了处理两个禁止的警告的方法。
如果有任何改进建议，我将不胜感激。
class DatabaseHelper extends SQLiteOpenHelper {
private static final int DB_VERSION = 21;
private String DB_PATH;
private static String DB_NAME = "My_Database.sqlite3";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
myContext = context;
DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
}
~~~~ @SuppressWarnings("RedundantThrows") ~~~~
void createDataBase() throws IOException {
boolean dbExist = checkDatabase();
~~~~ //noinspection StatementWithEmptyBody ~~~~
if (dbExist) {
} else {
getReadableDatabase();
close();
try {
copyDataBase();
} catch (IOException e) {
throw new IOException(e);
}
}
}
~~~~ @SuppressWarnings("EmptyCatchBlock") ~~~~
private boolean checkDatabase() {
SQLiteDatabase checkDB = null;
~~~~ //noinspection EmptyCatchBlock ~~~~
String myPath = DB_PATH + DB_NAME;
try {
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null;
}
private void copyDataBase() throws IOException {
InputStream myInput = myContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
}
void openDatabase() throws SQLiteException {
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 myDataBase, int oldVersion, int newVersion) {
if (newVersion > oldVersion)
try {
copyDataBase();
} catch (IOException e) {
e.printStackTrace();
}
}
}