Android 使用ORMLite 操作数据库
首先，到http://ormlite.com/releases/下载相关jar包：ormlite-android-4.48.jar和ormlite-core-4.48.jar；
第一步：继承OrmLiteSqliteOpenHelper类定义一个数据库帮助类；
1 public class MessageBeanHelper extends OrmLiteSqliteOpenHelper { 2 3 private static final String TAG = "MessageBeanHelper"; 4 5 // name of the database file for your application -- change to something 6 // appropriate for your app 7 private static final String DATABASE_NAME = "smartcareio.db"; 8 9 // any time you make changes to your database objects, you may have to 10 // increase the database version 11 private static final int DATABASE_VERSION = 1; 12 13 // the DAO object we use to access the TaskPackageBean table 14 private Dao<MessageBean, Integer> messageDao = null; 15 private RuntimeExceptionDao<MessageBean, Integer> messageRuntimeDao = null; 16 17 public MessageBeanHelper(Context context) { 18 super(context, DATABASE_NAME, null, DATABASE_VERSION); 19 } 20 21 /** 22 * This is called when the database is first created. Usually you should 23 * call createTable statements here to create the tables that will store 24 * your data. 25 */ 26 @Override 27 public void onCreate(SQLiteDatabase db, ConnectionSource connectionSource) { 28 try { 29 Log.i(TAG, "onCreate"); 30 TableUtils.createTable(connectionSource, MessageBean.class); 31 } catch (SQLException e) { 32 Log.e(TAG, "Can't create database!!!!"); 33 throw new RuntimeException(e); 34 } 35 } 36 37 /** 38 * This is called when your application is upgraded and it has a higher 39 * version number. This allows you to adjust the various data to match the 40 * new version number. 41 */ 42 @Override 43 public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource, 44 int oldVersion, int newVersion) { 45 try { 46 Log.i(TAG, "onUpgrade"); 47 TableUtils.dropTable(connectionSource, MessageBean.class, true); 48 // after we drop the old databases, we create the new ones 49 onCreate(db, connectionSource); 50 } catch (SQLException e) { 51 Log.e(TAG, "Can't drop databases!!!", e); 52 throw new RuntimeException(e); 53 } 54 } 55 56 /** 57 * Returns the Database Access Object (DAO) for our MessageBean class. 58 * It will create it or just give the cached value. 59 */ 60 public Dao<MessageBean, Integer> getDao() throws SQLException { 61 if (messageDao == null) { 62 messageDao = getDao(MessageBean.class); 63 } 64 return messageDao; 65 } 66 67 /** 68 * Returns the RuntimeExceptionDao (Database Access Object) version of a Dao 69 * for our MessageBean class. It will create it or just give the cached 70 * value. RuntimeExceptionDao only through RuntimeExceptions. 71 */ 72 public RuntimeExceptionDao<MessageBean, Integer> getMessageBeanDao() { 73 if (messageRuntimeDao == null) { 74 messageRuntimeDao = getRuntimeExceptionDao(MessageBean.class); 75 } 76 return messageRuntimeDao; 77 } 78 79 /** 80 * Close the database connections and clear any cached DAOs. 81 */ 82 @Override 83 public void close() { 84 super.close(); 85 messageDao = null; 86 messageRuntimeDao = null; 87 } 88 }
第二步：定义原始类；
1 public class Message { 2 3 @Expose 4 private int messageID;// 留言的id 5 @Expose 6 private String filePath; // 文件源路径,包含文件名 7 @Expose 8 private float length; // 录音文件的长度 9 10 public int getMessageID() { 11 return messageID; 12 } 13 14 public void setMessageID(int messageID) { 15 this.messageID = messageID; 16 } 17 18 public String getFilePath() { 19 return filePath; 20 } 21 22 public void setFilePath(String filePath) { 23 this.filePath = filePath; 24 } 25 26 public float getLength() { 27 return length; 28 } 29 30 public void setLength(float length) { 31 this.length = length; 32 }
第三步：定义Bean类，对要持久化的类进行注解，代表一张表，原始类也可以作为bean类，但为了区分原始类用于网络交互，bean类用于数据库交互，这里分开写(记住提供一个默认无参构造)
@DatabaseTable
1 public class MessageBean { 2 3 @DatabaseField(generatedId = true)//id自增长 4 private int messageID;// 留言的id 5 @DatabaseField 6 private String filePath; // 文件源路径,包含文件名 7 @DatabaseField 8 private float length; // 录音文件的长度 9 10 public MessageBean() {//无参构造 11 } 12 13 public MessageBean(Message message) { 14 CopyFromTaskPackage(message); 15 } 16 17 public void CopyFromTaskPackage(Message message) { 18 messageID = message.getMessageID(); 19 length = message.getLength(); 20 filePath = message.getFilePath(); 21 } 22 23 public Message ToMessage() { 24 Message message = new Message(); 25 message.setMessageID(messageID); 26 message.setFilePath(filePath); 27 message.setLength(length); 28 return message; 29 } 30 31 public int getMessageID() { 32 return messageID; 33 } 34 35 public void setMessageID(int messageID) { 36 this.messageID = messageID; 37 } 38 39 public String getFilePath() { 40 return filePath; 41 } 42 43 public void setFilePath(String filePath) { 44 this.filePath = filePath; 45 } 46 47 public float getLength() { 48 return length; 49 } 50 51 public void setLength(float length) { 52 this.length = length; 53 } 54 55 56 }
上面定义了一个套餐对象，我们来看一下它所用到的几个注解：
@DatabaseTable：表示定义了一个数据表，如果不指定名字，在Android中会以类名作为表名，如message就是SQLite数据库中的表名，我们也可以指定表名，@DatabaseTable(tableName = “tb_message”) 。
DatabaseField：表示定义了数据中的一个字段，id表示数据中的一个主键，如果指定为generatedId，表示自动增长id，我们不需要给它赋值。其他字段，可以使用columnName来指定字段名，canBeNull表示是否为空，这些赋值可以按照以下来指定
-（id = true, canBeNull = false）
- (columnName = “name”)
还有更多的注解用法，可以到官网查看它提供的文档。
第四步：定义Bean的IO类，增，删，查，改；
1 public class MessageIo { 2 3 private Context context; 4 private MessageBeanHelper messageBeanHelper; 5 private RuntimeExceptionDao<MessageBean, Integer> messageDao; 6 7 public MessageIo(Context context) { 8 this.context = context; 9 messageBeanHelper = new MessageBeanHelper(this.context); 10 messageDao = messageBeanHelper.getMessageBeanDao(); 11 } 12 13 public void InsertOrUpdateMessageInfo(Message message) { 14 SmartIoDBLock.Lock.writeLock().lock(); 15 messageDao.createOrUpdate(new MessageBean(message)); 16 SmartIoDBLock.Lock.writeLock().unlock(); 17 } 18 19 public void DeleteMessage(MessageBean messageBean) { 20 SmartIoDBLock.Lock.writeLock().lock(); 21 messageDao.delete(messageBean); 22 SmartIoDBLock.Lock.writeLock().unlock(); 23 } 24 25 public void DeleteMessageById(String messageId) { 26 SmartIoDBLock.Lock.writeLock().lock(); 27 try { 28 messageDao.deleteBuilder().where().eq("messageID", messageId).query(); 29 // messageDao.deleteBuilder().delete(); 30 } catch (SQLException e) { 31 e.printStackTrace(); 32 } 33 SmartIoDBLock.Lock.writeLock().unlock(); 34 } 35 36 public Message LoadMessage(String messageID) { 37 Message rtn = null; 38 List<MessageBean> temp = null; 39 SmartIoDBLock.Lock.writeLock().lock(); 40 try { 41 temp = messageDao.queryBuilder().where() 42 .eq("messageID", messageID).query(); 43 } catch (SQLException e) { 44 e.printStackTrace(); 45 } 46 SmartIoDBLock.Lock.writeLock().unlock(); 47 48 if (temp != null) { 49 for (MessageBean bean : temp) { 50 Message taskPackage = bean.ToMessage(); 51 rtn = taskPackage; 52 } 53 } 54 return rtn; 55 } 56 57 public List<Message> LoadAllMessages() { 58 List<Message> rtn = new ArrayList<Message>(); 59 List<MessageBean> temp = null; 60 SmartIoDBLock.Lock.writeLock().lock(); 61 temp = messageDao.queryForAll(); 62 SmartIoDBLock.Lock.writeLock().unlock(); 63 64 if (temp != null) { 65 for (MessageBean bean : temp) { 66 Message taskPackage = bean.ToMessage(); 67 rtn.add(taskPackage); 68 } 69 } 70 return rtn; 71 } 72 }
第五步：
具体使用方法：
1 MessageIo messageIo = new MessageIo(MyApplication.getContext()); 2 Message message = new Message(); 3 message.setFilePath(filePath); 4 message.setLength(seconds); 5 messageIo.InsertOrUpdateMessageInfo(message);
通过网络请求得到的json对象，相关的转化在这里就不详解了。。。。
