Android:如何按升序对此列进行排序?

时间:2015-08-22 22:13:32

标签: android database sorting listview

大家好!我正在尝试按升序排序列KEY_WORD,而不是KEY_ID,以显示在搜索建议的弹出列表视图中。我有一个搜索功能,当建议被激活时,我想要按字母顺序显示所有数据。

这是我的代码,我应该在哪里修改它?

DictionaryDatabase.java

public class DictionaryDatabase {
private static final String TAG = "DictionaryDatabase";

public static final String KEY_WORD = SearchManager.SUGGEST_COLUMN_TEXT_1;
public static final String KEY_DEFINITION = SearchManager.SUGGEST_COLUMN_TEXT_2;

private static final String DATABASE_NAME = "dictionary";
private static final String FTS_VIRTUAL_TABLE = "FTSdictionary";
private static final int DATABASE_VERSION = 2;

private final DictionaryOpenHelper mDatabaseOpenHelper;
private static final HashMap<String,String> mColumnMap = buildColumnMap();

public DictionaryDatabase(Context context) {
    mDatabaseOpenHelper = new DictionaryOpenHelper(context);
}

private static HashMap<String,String> buildColumnMap() {
    HashMap<String,String> map = new HashMap<String,String>();
    map.put(KEY_WORD, KEY_WORD);
    map.put(KEY_DEFINITION, KEY_DEFINITION);
    map.put(BaseColumns._ID, "rowid AS " +
            BaseColumns._ID);
    map.put(SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID, "rowid AS " +
            SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID);
    map.put(SearchManager.SUGGEST_COLUMN_SHORTCUT_ID, "rowid AS " +
            SearchManager.SUGGEST_COLUMN_SHORTCUT_ID);
    return map;
}

public Cursor getWord(String rowId, String[] columns) {
    String selection = "rowid = ?";
    String[] selectionArgs = new String[] {rowId};

    return query(selection, selectionArgs, columns);

}

public Cursor getWordMatches(String query, String[] columns) {
    String selection = KEY_WORD + " MATCH ?";
    String[] selectionArgs = new String[] {query+"*"};

    return query(selection, selectionArgs, columns);

}

private Cursor query(String selection, String[] selectionArgs, String[] columns) {

    SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
    builder.setTables(FTS_VIRTUAL_TABLE);
    builder.setProjectionMap(mColumnMap);

    Cursor cursor = builder.query(mDatabaseOpenHelper.getReadableDatabase(),
            columns, selection, selectionArgs, null, null, null);

    if (cursor == null) {
        return null;
    } else if (!cursor.moveToFirst()) {
        cursor.close();
        return null;
    }
    return cursor;
}

private static class DictionaryOpenHelper extends SQLiteOpenHelper {

    private final Context mHelperContext;
    private SQLiteDatabase mDatabase;

    private static final String FTS_TABLE_CREATE =
                "CREATE VIRTUAL TABLE " + FTS_VIRTUAL_TABLE +
                " USING fts3 (" +
                KEY_WORD + ", " +
                KEY_DEFINITION + ");";

    DictionaryOpenHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        mHelperContext = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        mDatabase = db;
        mDatabase.execSQL(FTS_TABLE_CREATE);
        loadDictionary();
    }

    private void loadDictionary() {
        new Thread(new Runnable() {
            public void run() {
                try {
                    loadWords();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }).start();
    }

    private void loadWords() throws IOException {
        Log.d(TAG, "Loading words...");
        final Resources resources = mHelperContext.getResources();
        InputStream inputStream = resources.openRawResource(R.raw.definitions);
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));

        try {
            String line;
            while ((line = reader.readLine()) != null) {
                String[] strings = TextUtils.split(line, "//");
                if (strings.length < 2) continue;
                long id = addWord(strings[0].trim(), strings[1].trim());
                if (id < 0) {
                    Log.e(TAG, "unable to add word: " + strings[0].trim());
                }
            }
        } finally {
            reader.close();
        }
        Log.d(TAG, "DONE loading words.");
    }


    public long addWord(String word, String definition) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_WORD, word);
        initialValues.put(KEY_DEFINITION, definition);

        return mDatabase.insert(FTS_VIRTUAL_TABLE, null, initialValues);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS " + FTS_VIRTUAL_TABLE);
        onCreate(db);
    }
}

}

DictionaryProvider.java

public class DictionaryProvider extends ContentProvider {
String TAG = "DictionaryProvider";

public static String AUTHORITY = "com.ec.idiomas.searchabledict.DictionaryProvider";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/dictionary");

public static final String WORDS_MIME_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE +
                                              "/vnd.ec.idiomas.searchabledict";
public static final String DEFINITION_MIME_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE +
                                                   "/vnd.eci.idiomas.searchabledict";

private DictionaryDatabase mDictionary;

private static final int SEARCH_WORDS = 0;
private static final int GET_WORD = 1;
private static final int SEARCH_SUGGEST = 2;
private static final int REFRESH_SHORTCUT = 3;
private static final UriMatcher sURIMatcher = buildUriMatcher();

private static UriMatcher buildUriMatcher() {
    UriMatcher matcher =  new UriMatcher(UriMatcher.NO_MATCH);
    matcher.addURI(AUTHORITY, "dictionary", SEARCH_WORDS);
    matcher.addURI(AUTHORITY, "dictionary/#", GET_WORD);
    matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, SEARCH_SUGGEST);
    matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", SEARCH_SUGGEST);

    matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_SHORTCUT, REFRESH_SHORTCUT);
    matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_SHORTCUT + "/*", REFRESH_SHORTCUT);
    return matcher;
}

@Override
public boolean onCreate() {
    mDictionary = new DictionaryDatabase(getContext());
    return true;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
                    String sortOrder) {

    switch (sURIMatcher.match(uri)) {
        case SEARCH_SUGGEST:
            if (selectionArgs == null) {
              throw new IllegalArgumentException(
                  "selectionArgs must be provided for the Uri: " + uri);
            }
            return getSuggestions(selectionArgs[0]);
        case SEARCH_WORDS:
            if (selectionArgs == null) {
              throw new IllegalArgumentException(
                  "selectionArgs must be provided for the Uri: " + uri);
            }
            return search(selectionArgs[0]);
        case GET_WORD:
            return getWord(uri);
        case REFRESH_SHORTCUT:
            return refreshShortcut(uri);
        default:
            throw new IllegalArgumentException("Unknown Uri: " + uri);
    }
}

private Cursor getSuggestions(String query) {
  query = query.toLowerCase();
  String[] columns = new String[] {
      BaseColumns._ID,
      DictionaryDatabase.KEY_WORD,

      SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID};

  return mDictionary.getWordMatches(query, columns);
}

private Cursor search(String query) {
  query = query.toLowerCase();
  String[] columns = new String[] {
      BaseColumns._ID,
      DictionaryDatabase.KEY_WORD,
      DictionaryDatabase.KEY_DEFINITION};

  return mDictionary.getWordMatches(query, columns);
}

private Cursor getWord(Uri uri) {
  String rowId = uri.getLastPathSegment();
  String[] columns = new String[] {
      DictionaryDatabase.KEY_WORD,
      DictionaryDatabase.KEY_DEFINITION};

  return mDictionary.getWord(rowId, columns);
}

private Cursor refreshShortcut(Uri uri) {

  String rowId = uri.getLastPathSegment();
  String[] columns = new String[] {
      BaseColumns._ID,
      DictionaryDatabase.KEY_WORD,
      DictionaryDatabase.KEY_DEFINITION,
      SearchManager.SUGGEST_COLUMN_SHORTCUT_ID,
      SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID};

  return mDictionary.getWord(rowId, columns);
}

@Override
public String getType(Uri uri) {
    switch (sURIMatcher.match(uri)) {
        case SEARCH_WORDS:
            return WORDS_MIME_TYPE;
        case GET_WORD:
            return DEFINITION_MIME_TYPE;
        case SEARCH_SUGGEST:
            return SearchManager.SUGGEST_MIME_TYPE;
        case REFRESH_SHORTCUT:
            return SearchManager.SHORTCUT_MIME_TYPE;
        default:
            throw new IllegalArgumentException("Unknown URL " + uri);
    }
}

@Override
public Uri insert(Uri uri, ContentValues values) {
    throw new UnsupportedOperationException();
}

@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
    throw new UnsupportedOperationException();
}

@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
    throw new UnsupportedOperationException();
}

}

0 个答案:

没有答案