使用OrmLite持久化SQLite（续）

sofh7777

上回说到我们已经建立了实体类Account和Order，下面我们来对它进行一个OrmLite的注解。@DatabaseTable(tableName = "accounts") //不写的话表名默认为类名(小写)accountpublic class Account implements Serializable {@DatabaseField(generatedId=true) //设置为自增长的主键private int aId;@DatabaseField //使用默认，列名与字段名相同private String aName;//一定要有一个无参的构造函数public Account() {super();}.....}　　

@DatabaseTable(tableName = "orders") public class Order implements Serializable {@DatabaseField(generatedId=true)private int oid;@DatabaseField private String oName;@DatabaseField(foreign=true) //简单地写一个外键=true就行了 方便大家理解private Account account;......}　　接着我们创建一个DataHelper类继承自OrmLiteSqliteOpenHelper（相当于数据库访问层）：
public class DataHelper extends OrmLiteSqliteOpenHelper {private static final String DATABASE_NAME = "test.db"; // 数据库名private static final int DATABASE_VERSION = 1; // 数据库版本号,以后如果对实体类进行了修改,想要更新一下数据库的话,改一下版本号就行了@SuppressWarnings("rawtypes")Map<String, Dao> daoMaps = null; // 所有DAO的集合，这不是必须的，你可以采用你的方式@SuppressWarnings("rawtypes")private void initDaoMaps() {daoMaps = new HashMap<String, Dao>();daoMaps.put("accountDao", null);daoMaps.put("orderDao", null);}public DataHelper(Context context) {super(context, DATABASE_NAME, null, DATABASE_VERSION); // 用过SQLite的都知道，我就不解释了initDaoMaps(); // 自定义方法 ,初始化dao的Map.}@Overridepublic void onCreate(SQLiteDatabase db, ConnectionSource connectionSource) {// 数据库创建时自动执行,以后不会再自动执行try {TableUtils.createTable(connectionSource, Account.class); // 创建Account表TableUtils.createTable(connectionSource, Order.class); // 创建Order表Log.i(DataHelper.class.getName(), "创建数据库成功！");} catch (Exception e) {Log.i(DataHelper.class.getName(), "创建数据库失败！", e);e.printStackTrace();}}@Overridepublic void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource,int arg2, int arg3) {// 数据库检测到版本号不同时自动执行,在这里我们应该：try {// 1:删除原有的旧表TableUtils.dropTable(connectionSource, Account.class, true);TableUtils.dropTable(connectionSource, Order.class, true);// 2:创建现在的新表onCreate(db, connectionSource);Log.e(DataHelper.class.getName(), "更新数据库成功");} catch (SQLException e) {Log.e(DataHelper.class.getName(), "更新数据库失败", e);e.printStackTrace();}}@Overridepublic void close() {super.close();daoMaps.clear();}//给它一个实体类，返回该实体类专用的Dao，功能很强大@SuppressWarnings("unchecked")public Dao<Account, Integer> getAccountDao() {Dao<Account, Integer> accountDao = daoMaps.get("accountDao");if (accountDao == null) {try {accountDao = getDao(Account.class);} catch (SQLException e) {e.printStackTrace();}}return accountDao;}@SuppressWarnings("unchecked")public Dao<Order, Integer> getOrderDao() {Dao<Order, Integer> orderDao = daoMaps.get("orderDao");if (orderDao == null) {try {orderDao = getDao(Order.class);} catch (SQLException e) {e.printStackTrace();}}return orderDao;}}
然后写业务逻辑层Service ：public class AccountService implements IAccountService{private Dao<Account, Integer> accountDao = null;public AccountService(Dao<Account, Integer> dao) {accountDao = dao;}public String reg(Account account) {boolean result = false;try {accountDao.create(account);result = true;} catch (SQLException e) {e.printStackTrace();}String msg= result ? "注册客户成功！" : "注册失败";return msg;}public Account load(String name) {Account account = null;Map<String, Object> accountMap = new HashMap<String, Object>();accountMap.put("aName", name);try {List<Account> list = accountDao.queryForFieldValues(accountMap);account = list != null && list.size() == 1 ? list.get(0) : null;} catch (SQLException e) {e.printStackTrace();}return account;}}
OrderService与上类似 ，我就不贴出来占位置了，接着到了我们的UI层。　　修改我们的Activity类，继承自OrmLiteBaseActivity<DataHelper>，这是一个抽象类OrmLiteBaseActivity<H extends OrmLiteSqliteOpenHelper>，它也是继承自Activity的，所以我们的Activity类相当于是间接继承自Activity：
public class OrmLiteTestActivity extends OrmLiteBaseActivity<DataHelper>implements OnClickListener {private Button btnRegAccount, btnAddOrder, btnShow;private TextView tvMsg = null;private IAccountService accountService = null;private IOrderService orderService = null;private int accountID = 0;private int orderID = 0;private String msg = "";@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);init();}private void init() {// 初始化serviceaccountService = new AccountService(getHelper().getAccountDao());orderService = new OrderService(getHelper().getOrderDao());btnRegAccount = (Button) this.findViewById(R.id.btnRegAccount);btnAddOrder = (Button) this.findViewById(R.id.btnAddOrder);btnShow = (Button) this.findViewById(R.id.btnShow);tvMsg = (TextView) this.findViewById(R.id.tvMsg);btnRegAccount.setOnClickListener(this);btnAddOrder.setOnClickListener(this);btnShow.setOnClickListener(this);}@Overridepublic void onClick(View v) {msg = "";switch (v.getId()) {case R.id.btnRegAccount:accountID++;Account account = new Account("客户" + accountID);msg = accountService.reg(account) ? "注册客户成功!" : "注册客户失败!";break;case R.id.btnAddOrder:orderID++;account = accountService.load("客户1");Order order = new Order("定单" + orderID, account);msg = orderService.addOrder(order) ? "添加定单成功!" : "添加定单失败!";break;case R.id.btnShow:List<Order> list = orderService.findOrderByAccountID(1);for (Order o : list) {msg += o.getOid() + ":" + o.getoName() + "\n";}break;default:break;}tvMsg.setText(msg);}}运行后效果如下： 最后是查找客户1的所有定单

　　这样我们就实现了使用OrmLite实现持久化数据了，完整代码可以在我的资源列表中下载：
　　http://download.csdn.net/detail/a_mean/3805488

　　欢迎交流、补充、找错，谢谢！