学习SQLite：集成Hibernate的基础知识

一般sqlite数据库，用作嵌入式数据库，用于安卓开发，本文应项目需求用于javaSE开发使用。

1.依赖：

<dependency>

<groupId>org.xerial</groupId>

<artifactId>sqlite-jdbc</artifactId>

<version>3.19.3</version>

</dependency>

2.数据库连接：

由于我采用的数据库路径是数据库名称，且需要变化，所以没有采用配置数据元的方式。

2.1读取配置文件：

loadProp();

加载数据库连接文件，并读取

2.2添加注解类（数据库模型）：

addCfgClass();

将数据库model添加到配置中

2.3初始化连接数据：

init();

创建数据库

2.4修改数据库连接路径：

setCfgUrl();

动态修改数据库连接路径

以下是数据库连接类：

public class SqliteConnection {

private InputStream dbStream;

//db文件路径

private String path;

private String prefix;

//配置文件

private Properties properties = new Properties();

private Configuration cfg = new Configuration();

private Map<String, Transaction> transactionMap = new HashMap<String, Transaction>();

private Map<String, SessionFactory> sessionFactoryMap = new HashMap<String, SessionFactory>();

privatestaticvolatile SqliteConnection conn;

private Session session;

private Map<String, Session> sessionMap = new HashMap<String, Session>();

private Transaction t;

privateboolean isAddClass = false;

private SqliteConnection(){}

publicstatic SqliteConnection getInstance(){

if(conn == null){

synchronized(SqliteConnection.class){

if(conn == null){

conn = new SqliteConnection();

conn.setCfg();

}

}

}

return conn;

}

public Session getSession() {

return session;

}

public Session getSession(String dbName) {

return sessionMap.get(dbName);

}

publicvoid setSession(Session session) {

this.session = session;

}

public Transaction getTransaction() {

return t;

}

publicvoid setTransaction(Transaction t) {

this.t = t;

}

/**

* 复制文件

* @param file1

* @param file2

* @throws IOException

*/

privatesynchronizedvoid copyFile(String file1,String file2) {

FileInputStream fis = null;

FileOutputStream fos = null;

try {

fis = new FileInputStream(file1);

fos = new FileOutputStream(file2);

int temp;

while((temp=fis.read())!=-1){

fos.write(temp);

}

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

} finally {

try {

if(fis != null) {

fis.close();

}

if(fos != null) {

fos.close();

}

} catch (IOException e) {

e.printStackTrace();

}

}

}

/**

* 开启事务

*/

publicsynchronizedvoid openTransaction(String dbName){

SessionFactory sessionFactory = getSessionFactory(dbName);

Session session = sessionFactory.getCurrentSession();

Transaction t = session.beginTransaction();

transactionMap.put(dbName, t);

sessionMap.put(dbName, session);

}

/**

* 提交事务

*/

publicsynchronizedvoid commit(String uuid){

Transaction t = transactionMap.get(uuid);

if(t != null){

t.commit();

}

transactionMap.remove(uuid);

sessionMap.remove(uuid);

}

/**

* 事务回滚

*/

publicsynchronizedvoid rollBack(String uuid){

Transaction t = transactionMap.get(uuid);

if(t != null){

t.rollback();

}

transactionMap.remove(uuid);

sessionMap.remove(uuid);

}

/**

* 设置配置

* @param model

*/

privatesynchronizedvoid setCfg(){

loadProp();

cfg.setProperties(properties);

addCfgClass();

}

/**

* 设置配置的url

*/

privatesynchronizedvoid setCfgUrl(String dbName){

cfg.setProperty("hibernate.connection.url", prefix + path + dbName + ".db");

}

/**

* 添加配置的注解类

*/

privatesynchronizedvoid addCfgClass(){

if(!isAddClass){

cfg.addAnnotatedClass(Model.class);

isAddClass = true;

}

}

/**

* 获取sessionFactory

* @param model

* @return

*/

publicsynchronized SessionFactory getSessionFactory(String dbName){

SessionFactory factory = sessionFactoryMap.get(dbName);

if(factory == null){

conn.init(dbName);

factory = cfg.buildSessionFactory();

sessionFactoryMap.put(dbName, factory);

}

return factory;

}

/**

* 加载配置文件

*/

privatesynchronizedvoid loadProp(){

try {

//获取文件位置，转为流，并加载

properties.load(SqliteConnection.class.getClassLoader().getResourceAsStream("sqlite.properties"));

Properties platformProperties = new Properties();

platformProperties.load(SqliteConnection.class.getClassLoader().getResourceAsStream("root.properties"));

path = platformProperties.getProperty("root") + "/" ;

prefix = properties.getProperty("prefix");

} catch (IOException e) {

e.printStackTrace();

}

}

/**

* 初始化数据

*/

privatesynchronizedvoid init(String dbName){

/*

* 判断文件是否存在

* 如果不存在，复制数据库文件，并且重命名

*/

File file = new File(path + dbName + ".db");

if(!file.exists()) {

try {

dbStream = SqliteConnection.class.getClassLoader().getResourceAsStream("sqlite.db");

FileUtils.copyInputStreamToFile(dbStream, file);

} catch (IOException e) {

e.printStackTrace();

} finally {

try {

dbStream.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

setCfgUrl(dbName);

}

}

最后添加手写的编程式事务，便可以使用hibernate连接sqlite数据库了。