java - Creating android app Database with big amount of data

Question

The database of my application need to be filled with a lot of data, so during onCreate(), it's not only some create table sql instructions, there is a lot of inserts. The solution I chose is to store all this instructions in a sql file located in res/raw and which is loaded with Resources.openRawResource(id).

It works well but I face to encoding issue, I have some accentuated caharacters in the sql file which appears bad in my application. This my code to do this:

public String getFileContent(Resources resources, int rawId) throws
IOException
  {
    InputStream is = resources.openRawResource(rawId);
    int size = is.available();
    // Read the entire asset into a local byte buffer.
    byte[] buffer = new byte[size];
    is.read(buffer);
    is.close();
    // Convert the buffer into a string.
    return new String(buffer);
  }

public void onCreate(SQLiteDatabase db) {
   try {
        // get file content
        String sqlCode = getFileContent(mCtx.getResources(), R.raw.db_create);
        // execute code
        for (String sqlStatements : sqlCode.split(";"))
        {
            db.execSQL(sqlStatements);
        }

        Log.v("Creating database done.");
        } catch (IOException e) {
            // Should never happen!
            Log.e("Error reading sql file " + e.getMessage(), e);
            throw new RuntimeException(e);
        } catch (SQLException e) {
            Log.e("Error executing sql code " + e.getMessage(), e);
            throw new RuntimeException(e);
        }

The solution I found to avoid this is to load the sql instructions from a huge static final String instead of a file, and all accentuated characters appear well.

But isn't there a more elegant way to load sql instructions than a big static final String attribute with all sql instructions?

Answer 1

I think your problem is in this line:

return new String(buffer);

You're converting the array of bytes in to a java.lang.String but you're not telling Java/Android the encoding to use. So the bytes for your accented characters aren't being converted correctly as the wrong encoding is being used.

If you use the String(byte[],<encoding>) constructor you can specify the encoding your file has and your characters will be converted correctly.