violetIC的专栏

public class DBHelper extends OrmLiteSqliteOpenHelper {private static final String DB_NAME = "app_noname.db";private static final int DB_VERSION = 1;private static DBHelper instance;private Map<String, Dao> daos = new HashMap<String, Dao>();public DBHelper(Context context) {super(context, DB_NAME, null, DB_VERSION); // 创建数据库}public static synchronized DBHelper getInstance(Context context){if ( instance == null) {synchronized (DBHelper. class) {if ( instance == null) {instance = new DBHelper(context);}}}return instance;}@Overridepublic void onCreate(SQLiteDatabase arg0, ConnectionSource connectionSource) {try {TableUtils. createTable(connectionSource, CountryInfo.class );} catch (SQLException e) {// TODOe.printStackTrace();}}@Overridepublic void onUpgrade(SQLiteDatabase arg0, ConnectionSource arg1, int arg2,int arg3) {try {TableUtils. dropTable(arg1, CountryInfo. class, true);} catch (SQLException e) {// TODOe.printStackTrace();}}public synchronized Dao getDao(Class clazz) throws SQLException{Dao dao = null;String className = clazz.getSimpleName();if ( daos.containsKey(className)) {dao = daos.get(className);}if (dao == null) {dao = super .getDao(clazz);daos.put(className, dao);}return dao;}@Overridepublic void close() {for (String key : daos.keySet()) {Dao dao = daos .get(key);dao = null;}super.close();}}

CountryDao类

public class CountryDao {private Context mContext;private DBHelper mDbHelper;private Dao<CountryInfo, Integer> mCountryDao;public CountryDao(Context context) {mContext = context;mDbHelper = DBHelper. getInstance( mContext);try {mCountryDao = mDbHelper .getDao(CountryInfo. class);} catch (SQLException e) {// TODOe.printStackTrace();}}/*** @Title : addCountry* @Description : 新增一个country信息* @param countryInfo* @return void 返回类型* @throws*/public void addCountry(CountryInfo countryInfo){try {mCountryDao.create(countryInfo);System. out.println( "country数据添加成功" );} catch (SQLException e) {// TODOe.printStackTrace();}}public List<CountryInfo> findByNo(String value){List<CountryInfo> countryInfos = null;try {countryInfos = mCountryDao.queryBuilder().where().eq( "no", value).query();System. out.println( "country数据查询成功" );} catch (SQLException e) {e.printStackTrace();}return countryInfos;} }

测试代码：

CountryDao countryDao = new CountryDao( this);countryDao.addCountry(getCountryData());List<CountryInfo> findByNos = countryDao.findByNo("12345" );if (findByNos.size() > 0) {for (CountryInfo countryInfo : findByNos) {System. err.println(countryInfo.getName());}}

，如果寒暄只是打个招呼就了事的话，那与猴子的呼叫声有什么不同呢?事实上，