Question

嗨，伙计们！首先，我是新手。我的数据库中有一个名为的列的 definition 即可。在这个专栏中会有很多句子。我想在每个句子之后换行（段落）。但我不知道该怎么做。我试图在句子后输入\ n但没有任何反应。有人能帮助我吗？

有我的源代码：

DictionaryDataHelper

public class DictionaryDatabaseHelper extends SQLiteOpenHelper {

final static String DICTIONARY_DATABASE="dictionary";
final static String ITEM_ID_COLUMN="id";
final static String WORD_COLUMN="word";
final static String DEFINITION_COLUMN="definition";


final static String CREATE_DATABASE_QUERY="CREATE TABLE "+DICTIONARY_DATABASE+" ( "+
ITEM_ID_COLUMN+" INTEGER PRIMARY KEY AUTOINCREMENT, "+
WORD_COLUMN+" TEXT , "+
DEFINITION_COLUMN+" TEXT)";


final static String ON_UPGRADE_QUERY="DROP TABLE "+DICTIONARY_DATABASE;

Context context;


public DictionaryDatabaseHelper(Context context, String name,
        CursorFactory factory, int version) {
    super(context, DICTIONARY_DATABASE, factory, version);
    this.context=context;

}

@Override
public void onCreate(SQLiteDatabase database) {
        database.execSQL(CREATE_DATABASE_QUERY);    
}

@Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
    database.execSQL(ON_UPGRADE_QUERY);
    onCreate(database);

}

public long insertData(WordDefinition wordDefinition) {
    SQLiteDatabase database=this.getWritableDatabase();
    ContentValues values=new ContentValues();

    values.put(WORD_COLUMN, wordDefinition.word);
    values.put(DEFINITION_COLUMN, wordDefinition.definition);

    return database.insert(DICTIONARY_DATABASE, null, values);      

}

public long updateData(WordDefinition wordDefinition) {
    SQLiteDatabase database=this.getWritableDatabase();
    ContentValues values=new ContentValues();

    values.put(WORD_COLUMN, wordDefinition.word);
    values.put(DEFINITION_COLUMN, wordDefinition.definition);

    return database.update(DICTIONARY_DATABASE, values, WORD_COLUMN+" =?", new String[]{wordDefinition.word});  

}

public void deleteData(WordDefinition wordDefinition) {
    SQLiteDatabase database=this.getWritableDatabase();
    String queryString="DELETE FROM "+DICTIONARY_DATABASE+" WHERE "+WORD_COLUMN+" = '"+wordDefinition.word+"'";

    database.execSQL(queryString);
}

public ArrayList<WordDefinition> getAllWords() {
    ArrayList<WordDefinition> arrayList=new ArrayList<WordDefinition>();
    SQLiteDatabase database=this.getReadableDatabase();

    String selectAllQueryString="SELECT * FROM "+DICTIONARY_DATABASE;
    Cursor cursor=database.rawQuery(selectAllQueryString, null);

    if (cursor.moveToFirst()) {
        do {            
            WordDefinition wordDefinition=new WordDefinition(cursor.getString(cursor.getColumnIndex(WORD_COLUMN)), cursor.getString(cursor.getColumnIndex(DEFINITION_COLUMN)));
            arrayList.add(wordDefinition);              
        } while (cursor.moveToNext());          
    }   
    return arrayList;
}

public WordDefinition getWordDefinition(String word) {
    SQLiteDatabase database=this.getReadableDatabase();
    WordDefinition wordDefinition=null;

    String selectQueryString="SELECT * FROM "+DICTIONARY_DATABASE+ " WHERE "+WORD_COLUMN+" = '"+word+ "'";
    Cursor cursor=database.rawQuery(selectQueryString, null);

    if (cursor.moveToFirst()) {
        wordDefinition=new WordDefinition(cursor.getString(cursor.getColumnIndex(WORD_COLUMN)), cursor.getString(cursor.getColumnIndex(DEFINITION_COLUMN)));

    }   

    return wordDefinition;

}

public WordDefinition getWordDefinition(long id) {
    SQLiteDatabase database=this.getReadableDatabase();
    WordDefinition wordDefinition=null;

    String selectQueryString="SELECT * FROM "+DICTIONARY_DATABASE+ " WHERE "+ITEM_ID_COLUMN+" = '"+id+ "'";
    Cursor cursor=database.rawQuery(selectQueryString, null);

    if (cursor.moveToFirst()) {
        wordDefinition=new WordDefinition(cursor.getString(cursor.getColumnIndex(WORD_COLUMN)), cursor.getString(cursor.getColumnIndex(DEFINITION_COLUMN)));

    }   

    return wordDefinition;

}

public void initializeDatabaseFortheFirstTime(ArrayList<WordDefinition> wordDefinitions) {
    SQLiteDatabase database=this.getWritableDatabase();
    database.execSQL("BEGIN");

    ContentValues contentValues=new ContentValues();

    for (WordDefinition wordDefinition : wordDefinitions) {
        contentValues.put(WORD_COLUMN, wordDefinition.word);
        contentValues.put(DEFINITION_COLUMN, wordDefinition.definition);            
        database.insert(DICTIONARY_DATABASE, null, contentValues);
    }
    database.execSQL("COMMIT");

}


}

DictionaryListActivity

public class DictionaryListActivity extends Activity {

TextView userTextView;
EditText searchEditText;
Button searchButton;
ListView dictionaryListView;

String logTagString="DICTIONARY";
ArrayList<WordDefinition> allWordDefinitions=new ArrayList<WordDefinition>();


DictionaryDatabaseHelper myDictionaryDatabaseHelper;
SharedPreferences sharedPreferences;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dictionary_list);

    Log.d("DICTIONARY", "second activity started");


    userTextView=(TextView) findViewById(R.id.personTextView);
    userTextView.setText(getIntent().getStringExtra(MainActivity.USER_NAME_STRING));

    searchEditText=(EditText) findViewById(R.id.searchEditText);
    searchButton=(Button) findViewById(R.id.searchButton);
    dictionaryListView=(ListView) findViewById(R.id.dictionaryListView);

    myDictionaryDatabaseHelper=new DictionaryDatabaseHelper(this, "Dictionary", null, 1);
    sharedPreferences=getSharedPreferences(MainActivity.SHARED_NAME_STRING, MODE_PRIVATE);


    boolean initialized=sharedPreferences.getBoolean("initialized", false);

    if (initialized==false) {
        //Log.d(logTagString, "initializing for the first time");
        initializeDatabase();
        SharedPreferences.Editor editor=sharedPreferences.edit();
        editor.putBoolean("initialized", true);
        editor.commit();

    }else {
        Log.d(logTagString, "db already initialized");
    }

    allWordDefinitions=myDictionaryDatabaseHelper.getAllWords();

    dictionaryListView.setAdapter(new BaseAdapter() {

        @Override
        public View getView(int position, View view, ViewGroup arg2) {
            if (view==null) {
                view=getLayoutInflater().inflate(R.layout.list_item, null);
            }
            TextView textView=(TextView) view.findViewById(R.id.listItemTextView);
            textView.setText(allWordDefinitions.get(position).word);

            return view;
        }

        @Override
        public long getItemId(int arg0) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public Object getItem(int arg0) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return allWordDefinitions.size();
        }
    });

    dictionaryListView.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View view, int position,
                long arg3) {
            Intent intent =new Intent(DictionaryListActivity.this, WordDefinitionDetailActivity.class);
            intent.putExtra("word", allWordDefinitions.get(position).word);
            intent.putExtra("definition", allWordDefinitions.get(position).definition);

            startActivity(intent);
        }
    });

    searchButton.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            String string=searchEditText.getText().toString();

            WordDefinition wordDefinition=myDictionaryDatabaseHelper.getWordDefinition(string);

            if (wordDefinition==null) {
                Toast.makeText(DictionaryListActivity.this, "Expressão não encontrada.", Toast.LENGTH_LONG).show();
            }else {
                Intent intent =new Intent(DictionaryListActivity.this, WordDefinitionDetailActivity.class);
                intent.putExtra("word", wordDefinition.word);
                intent.putExtra("definition", wordDefinition.definition);

                startActivity(intent);
            }


        }
    });




}

//


private void initializeDatabase() {
    InputStream inputStream=getResources().openRawResource(R.raw.dictionary);
    BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream));
    DictionaryLoader.loadData(bufferedReader, myDictionaryDatabaseHelper);

}

}

DictionaryLoader

 public class DictionaryLoader {



public static void loadData(BufferedReader bufferedReader, DictionaryDatabaseHelper dictionaryDatabaseHelper) {

    ArrayList<WordDefinition> allWords=new ArrayList<WordDefinition>();

    try {

        BufferedReader fileReader=bufferedReader;

        try {

            int c=17;
            c=fileReader.read();
            while (c!=(-1)) {

                StringBuilder stringBuilder=new StringBuilder();

                while ((char)c!='\n'&&c!=-1) {
                    try {
                        stringBuilder.append((char)c);
                    } catch (Exception e) {
                        // TODO Auto-generated catch block
                        System.out.println(stringBuilder.length());
                        //e.printStackTrace();
                    }
                    c= fileReader.read();
                    if (c==-1) {
                        return;
                    }
                }


                String wordString=stringBuilder.toString();

                ArrayList<String> definition=new ArrayList<String>();
                while (c=='\n'||c=='\t') {
                    c= fileReader.read();
                    if (c=='\n'||c=='\t'||c=='\r') {
                        StringBuilder stringBuilder2=new StringBuilder();
                        while (c!='\n') {
                            stringBuilder2.append((char)c);
                            c=fileReader.read();
                        }
                        String definitionString=stringBuilder2.toString();
                        definition.add(definitionString);
                    }else {
                        break;
                    }

                }

                wordString=wordString.trim();
                //Logger.log("word Loaded: "+(++counter)+" :"+wordString);
                allWords.add(new WordDefinition(wordString, definition));
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {

            dictionaryDatabaseHelper.initializeDatabaseFortheFirstTime(allWords);
            fileReader.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

}

Answer 1

如果您使用ContentValues进行插入，则您的字符串可以包含换行符（\n），并且插入就好了。据我所知，加载单词的代码永远不会将这个字符添加到它构建的字符串中。

此外，您不应该执行此类BEGIN和COMMIT语句。正确的方式如下：

sqliteDb.beginTransaction();
try {
    // your database operations here
    sqliteDb.setTransactionSuccessful();
} finally {
    sqliteDb.endTransaction();
}

我的sqlite专栏中的新行

1 个答案: