今天在论坛上看到一位朋友希望自己在java中动态的创建hibernate的配置文件(并不是生成而是创建hibernate配置文件对象),脑海中第一个想到的就是spring源码,因为spring有整合hibernate的功能,于是翻阅了spring的代码一看,果然很简单。下面先发断简单的demo。
public static void main(String[] args) throws Exception {
Configuration configuration = new Configuration();
Properties properties = new Properties();
properties.setProperty("hibernate.dialect",
"org.hibernate.dialect.SQLServerDialect");
String[] mappingResources = new String[1];
mappingResources[0] = "com/syj/domain/Issue.hbm.xml";
for (int i = 0; i < mappingResources.length; i++) {
Resource resource = new ClassPathResource(mappingResources[i]
.trim(), Thread.currentThread().getContextClassLoader());
configuration.addInputStream(resource.getInputStream());
}
configuration.addProperties(properties);
configuration.buildSessionFactory();
}
Configuration configuration = new Configuration();
Properties properties = new Properties();
properties.setProperty("hibernate.dialect",
"org.hibernate.dialect.SQLServerDialect");
String[] mappingResources = new String[1];
mappingResources[0] = "com/syj/domain/Issue.hbm.xml";
for (int i = 0; i < mappingResources.length; i++) {
Resource resource = new ClassPathResource(mappingResources[i]
.trim(), Thread.currentThread().getContextClassLoader());
configuration.addInputStream(resource.getInputStream());
}
configuration.addProperties(properties);
configuration.buildSessionFactory();
}
上面代码中properties还缺少很多属性,因为只是个demo所以我没有填写全部的属性,其实这里的属性就是指hibernate.cfg.xml中那些属性,例如hibernate.connection.provider_class,show_sql等等。添加到properties中就可以了。
为什么想到spring的源码呢,下面来看spring中如何整合的
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</prop>
<prop key="hibernate.show_sql">false</prop>
<prop key="hibernate.format_sql">false</prop>
<prop key="hibernate.use_sql_comments">false</prop>
<!-- 为单向关联(一对一, 多对一)的外连接抓取(outer join fetch)树设置最大深度. 值为0意味着将关闭默认的外连接抓取 -->
<prop key="hibernate.max_fetch_depth">3</prop>
<!-- 为Hibernate关联的批量抓取设置默认数量 -->
<prop key="hibernate.default_batch_fetch_size">8</prop>
<!-- 强制Hibernate按照被更新数据的主键,为SQL更新排序。这么做将减少在高并发系统中事务的死锁。 -->
<prop key="hibernate.order_updates">true</prop>
<!-- session在事务完成后将被自动清洗(flush) -->
<prop key="hibernate.transaction.flush_before_completion">true</prop>
<!-- Oracle限制那些通过JDBC驱动传输的字节数组的数目. 如果你希望使用二进值 (binary)或 可序列化的 (serializable)类型的大对象, 你应该开启 hibernate.jdbc.use_streams_for_binary属性. -->
<prop key="hibernate.bytecode.use_reflection_optimizer">true</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>com/xxx/domain/xxx.hbm.xml</value>
</list>
</property>
</bean>
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</prop>
<prop key="hibernate.show_sql">false</prop>
<prop key="hibernate.format_sql">false</prop>
<prop key="hibernate.use_sql_comments">false</prop>
<!-- 为单向关联(一对一, 多对一)的外连接抓取(outer join fetch)树设置最大深度. 值为0意味着将关闭默认的外连接抓取 -->
<prop key="hibernate.max_fetch_depth">3</prop>
<!-- 为Hibernate关联的批量抓取设置默认数量 -->
<prop key="hibernate.default_batch_fetch_size">8</prop>
<!-- 强制Hibernate按照被更新数据的主键,为SQL更新排序。这么做将减少在高并发系统中事务的死锁。 -->
<prop key="hibernate.order_updates">true</prop>
<!-- session在事务完成后将被自动清洗(flush) -->
<prop key="hibernate.transaction.flush_before_completion">true</prop>
<!-- Oracle限制那些通过JDBC驱动传输的字节数组的数目. 如果你希望使用二进值 (binary)或 可序列化的 (serializable)类型的大对象, 你应该开启 hibernate.jdbc.use_streams_for_binary属性. -->
<prop key="hibernate.bytecode.use_reflection_optimizer">true</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>com/xxx/domain/xxx.hbm.xml</value>
</list>
</property>
</bean>
大家都知道spring的依赖注入,其实依赖注入很简单这里不做此介绍,我们按照spring的注入流程思考就可以了,下面看看spring优雅的实现把。在这里我们只关注LocalSessionFactoryBean的一个方法:
protected SessionFactory buildSessionFactory() throws Exception {
// Create Configuration instance.
Configuration config = newConfiguration();
DataSource dataSource = getDataSource();
if (dataSource != null) {
// Make given DataSource available for SessionFactory configuration.
configTimeDataSourceHolder.set(dataSource);
}
if (this.jtaTransactionManager != null) {
// Make Spring-provided JTA TransactionManager available.
configTimeTransactionManagerHolder.set(this.jtaTransactionManager);
}
if (this.lobHandler != null) {
// Make given LobHandler available for SessionFactory configuration.
// Do early because because mapping resource might refer to custom types.
configTimeLobHandlerHolder.set(this.lobHandler);
}
// Analogous to Hibernate EntityManager's Ejb3Configuration:
// Hibernate doesn't allow setting the bean ClassLoader explicitly,
// so we need to expose it as thread context ClassLoader accordingly.
Thread currentThread = Thread.currentThread();
ClassLoader threadContextClassLoader = currentThread.getContextClassLoader();
boolean overrideClassLoader =
(this.beanClassLoader != null && !this.beanClassLoader.equals(threadContextClassLoader));
if (overrideClassLoader) {
currentThread.setContextClassLoader(this.beanClassLoader);
}
try {
if (this.jtaTransactionManager != null) {
// Set Spring-provided JTA TransactionManager as Hibernate property.
config.setProperty(
Environment.TRANSACTION_MANAGER_STRATEGY, LocalTransactionManagerLookup.class.getName());
config.setProperty(
Environment.TRANSACTION_STRATEGY, JTATransactionFactory.class.getName());
}
else {
// Set connection release mode "on_close" as default.
// This was the case for Hibernate 3.0; Hibernate 3.1 changed
// it to "auto" (i.e. "after_statement" or "after_transaction").
// However, for Spring's resource management (in particular for
// HibernateTransactionManager), "on_close" is the better default.
config.setProperty(Environment.RELEASE_CONNECTIONS, ConnectionReleaseMode.ON_CLOSE.toString());
}
if (isExposeTransactionAwareSessionFactory()) {
// Set Hibernate 3.1 CurrentSessionContext implementation,
// providing the Spring-managed Session as current Session.
// Can be overridden by a custom value for the corresponding Hibernate property.
config.setProperty(Environment.CURRENT_SESSION_CONTEXT_CLASS, SpringSessionContext.class.getName());
}
if (this.entityInterceptor != null) {
// Set given entity interceptor at SessionFactory level.
config.setInterceptor(this.entityInterceptor);
}
if (this.namingStrategy != null) {
// Pass given naming strategy to Hibernate Configuration.
config.setNamingStrategy(this.namingStrategy);
}
if (this.typeDefinitions != null) {
// Register specified Hibernate type definitions.
Mappings mappings = config.createMappings();
for (int i = 0; i < this.typeDefinitions.length; i++) {
TypeDefinitionBean typeDef = this.typeDefinitions[i];
mappings.addTypeDef(typeDef.getTypeName(), typeDef.getTypeClass(), typeDef.getParameters());
}
}
if (this.filterDefinitions != null) {
// Register specified Hibernate FilterDefinitions.
for (int i = 0; i < this.filterDefinitions.length; i++) {
config.addFilterDefinition(this.filterDefinitions[i]);
}
}
if (this.configLocations != null) {
for (int i = 0; i < this.configLocations.length; i++) {
// Load Hibernate configuration from given location.
config.configure(this.configLocations[i].getURL());
}
}
if (this.hibernateProperties != null) {
// Add given Hibernate properties to Configuration.
config.addProperties(this.hibernateProperties);
}
if (dataSource != null) {
boolean actuallyTransactionAware =
(isUseTransactionAwareDataSource() || dataSource instanceof TransactionAwareDataSourceProxy);
// Set Spring-provided DataSource as Hibernate ConnectionProvider.
config.setProperty(Environment.CONNECTION_PROVIDER,
actuallyTransactionAware ?
TransactionAwareDataSourceConnectionProvider.class.getName() :
LocalDataSourceConnectionProvider.class.getName());
}
if (this.mappingResources != null) {
// Register given Hibernate mapping definitions, contained in resource files.
for (int i = 0; i < this.mappingResources.length; i++) {
Resource resource = new ClassPathResource(this.mappingResources[i].trim(), this.beanClassLoader);
config.addInputStream(resource.getInputStream());
}
}
if (this.mappingLocations != null) {
// Register given Hibernate mapping definitions, contained in resource files.
for (int i = 0; i < this.mappingLocations.length; i++) {
config.addInputStream(this.mappingLocations[i].getInputStream());
}
}
if (this.cacheableMappingLocations != null) {
// Register given cacheable Hibernate mapping definitions, read from the file system.
for (int i = 0; i < this.cacheableMappingLocations.length; i++) {
config.addCacheableFile(this.cacheableMappingLocations[i].getFile());
}
}
if (this.mappingJarLocations != null) {
// Register given Hibernate mapping definitions, contained in jar files.
for (int i = 0; i < this.mappingJarLocations.length; i++) {
Resource resource = this.mappingJarLocations[i];
config.addJar(resource.getFile());
}
}
if (this.mappingDirectoryLocations != null) {
// Register all Hibernate mapping definitions in the given directories.
for (int i = 0; i < this.mappingDirectoryLocations.length; i++) {
File file = this.mappingDirectoryLocations[i].getFile();
if (!file.isDirectory()) {
throw new IllegalArgumentException(
"Mapping directory location [" + this.mappingDirectoryLocations[i] +
"] does not denote a directory");
}
config.addDirectory(file);
}
}
if (this.entityCacheStrategies != null) {
// Register cache strategies for mapped entities.
for (Enumeration classNames = this.entityCacheStrategies.propertyNames(); classNames.hasMoreElements();) {
String className = (String) classNames.nextElement();
String[] strategyAndRegion =
StringUtils.commaDelimitedListToStringArray(this.entityCacheStrategies.getProperty(className));
if (strategyAndRegion.length > 1) {
config.setCacheConcurrencyStrategy(className, strategyAndRegion[0], strategyAndRegion[1]);
}
else if (strategyAndRegion.length > 0) {
config.setCacheConcurrencyStrategy(className, strategyAndRegion[0]);
}
}
}
if (this.collectionCacheStrategies != null) {
// Register cache strategies for mapped collections.
for (Enumeration collRoles = this.collectionCacheStrategies.propertyNames(); collRoles.hasMoreElements();) {
String collRole = (String) collRoles.nextElement();
String[] strategyAndRegion =
StringUtils.commaDelimitedListToStringArray(this.collectionCacheStrategies.getProperty(collRole));
if (strategyAndRegion.length > 1) {
config.setCollectionCacheConcurrencyStrategy(collRole, strategyAndRegion[0], strategyAndRegion[1]);
}
else if (strategyAndRegion.length > 0) {
config.setCollectionCacheConcurrencyStrategy(collRole, strategyAndRegion[0]);
}
}
}
if (this.eventListeners != null) {
// Register specified Hibernate event listeners.
for (Iterator it = this.eventListeners.entrySet().iterator(); it.hasNext();) {
Map.Entry entry = (Map.Entry) it.next();
Assert.isTrue(entry.getKey() instanceof String, "Event listener key needs to be of type String");
String listenerType = (String) entry.getKey();
Object listenerObject = entry.getValue();
if (listenerObject instanceof Collection) {
Collection listeners = (Collection) listenerObject;
EventListeners listenerRegistry = config.getEventListeners();
Object[] listenerArray =
(Object[]) Array.newInstance(listenerRegistry.getListenerClassFor(listenerType), listeners.size());
listenerArray = listeners.toArray(listenerArray);
config.setListeners(listenerType, listenerArray);
}
else {
config.setListener(listenerType, listenerObject);
}
}
}
// Perform custom post-processing in subclasses.
postProcessConfiguration(config);
// Build SessionFactory instance.
logger.info("Building new Hibernate SessionFactory");
this.configuration = config;
return newSessionFactory(config);
}
finally {
if (dataSource != null) {
// Reset DataSource holder.
configTimeDataSourceHolder.set(null);
}
if (this.jtaTransactionManager != null) {
// Reset TransactionManager holder.
configTimeTransactionManagerHolder.set(null);
}
if (this.lobHandler != null) {
// Reset LobHandler holder.
configTimeLobHandlerHolder.set(null);
}
if (overrideClassLoader) {
// Reset original thread context ClassLoader.
currentThread.setContextClassLoader(threadContextClassLoader);
}
}
}
// Create Configuration instance.
Configuration config = newConfiguration();
DataSource dataSource = getDataSource();
if (dataSource != null) {
// Make given DataSource available for SessionFactory configuration.
configTimeDataSourceHolder.set(dataSource);
}
if (this.jtaTransactionManager != null) {
// Make Spring-provided JTA TransactionManager available.
configTimeTransactionManagerHolder.set(this.jtaTransactionManager);
}
if (this.lobHandler != null) {
// Make given LobHandler available for SessionFactory configuration.
// Do early because because mapping resource might refer to custom types.
configTimeLobHandlerHolder.set(this.lobHandler);
}
// Analogous to Hibernate EntityManager's Ejb3Configuration:
// Hibernate doesn't allow setting the bean ClassLoader explicitly,
// so we need to expose it as thread context ClassLoader accordingly.
Thread currentThread = Thread.currentThread();
ClassLoader threadContextClassLoader = currentThread.getContextClassLoader();
boolean overrideClassLoader =
(this.beanClassLoader != null && !this.beanClassLoader.equals(threadContextClassLoader));
if (overrideClassLoader) {
currentThread.setContextClassLoader(this.beanClassLoader);
}
try {
if (this.jtaTransactionManager != null) {
// Set Spring-provided JTA TransactionManager as Hibernate property.
config.setProperty(
Environment.TRANSACTION_MANAGER_STRATEGY, LocalTransactionManagerLookup.class.getName());
config.setProperty(
Environment.TRANSACTION_STRATEGY, JTATransactionFactory.class.getName());
}
else {
// Set connection release mode "on_close" as default.
// This was the case for Hibernate 3.0; Hibernate 3.1 changed
// it to "auto" (i.e. "after_statement" or "after_transaction").
// However, for Spring's resource management (in particular for
// HibernateTransactionManager), "on_close" is the better default.
config.setProperty(Environment.RELEASE_CONNECTIONS, ConnectionReleaseMode.ON_CLOSE.toString());
}
if (isExposeTransactionAwareSessionFactory()) {
// Set Hibernate 3.1 CurrentSessionContext implementation,
// providing the Spring-managed Session as current Session.
// Can be overridden by a custom value for the corresponding Hibernate property.
config.setProperty(Environment.CURRENT_SESSION_CONTEXT_CLASS, SpringSessionContext.class.getName());
}
if (this.entityInterceptor != null) {
// Set given entity interceptor at SessionFactory level.
config.setInterceptor(this.entityInterceptor);
}
if (this.namingStrategy != null) {
// Pass given naming strategy to Hibernate Configuration.
config.setNamingStrategy(this.namingStrategy);
}
if (this.typeDefinitions != null) {
// Register specified Hibernate type definitions.
Mappings mappings = config.createMappings();
for (int i = 0; i < this.typeDefinitions.length; i++) {
TypeDefinitionBean typeDef = this.typeDefinitions[i];
mappings.addTypeDef(typeDef.getTypeName(), typeDef.getTypeClass(), typeDef.getParameters());
}
}
if (this.filterDefinitions != null) {
// Register specified Hibernate FilterDefinitions.
for (int i = 0; i < this.filterDefinitions.length; i++) {
config.addFilterDefinition(this.filterDefinitions[i]);
}
}
if (this.configLocations != null) {
for (int i = 0; i < this.configLocations.length; i++) {
// Load Hibernate configuration from given location.
config.configure(this.configLocations[i].getURL());
}
}
if (this.hibernateProperties != null) {
// Add given Hibernate properties to Configuration.
config.addProperties(this.hibernateProperties);
}
if (dataSource != null) {
boolean actuallyTransactionAware =
(isUseTransactionAwareDataSource() || dataSource instanceof TransactionAwareDataSourceProxy);
// Set Spring-provided DataSource as Hibernate ConnectionProvider.
config.setProperty(Environment.CONNECTION_PROVIDER,
actuallyTransactionAware ?
TransactionAwareDataSourceConnectionProvider.class.getName() :
LocalDataSourceConnectionProvider.class.getName());
}
if (this.mappingResources != null) {
// Register given Hibernate mapping definitions, contained in resource files.
for (int i = 0; i < this.mappingResources.length; i++) {
Resource resource = new ClassPathResource(this.mappingResources[i].trim(), this.beanClassLoader);
config.addInputStream(resource.getInputStream());
}
}
if (this.mappingLocations != null) {
// Register given Hibernate mapping definitions, contained in resource files.
for (int i = 0; i < this.mappingLocations.length; i++) {
config.addInputStream(this.mappingLocations[i].getInputStream());
}
}
if (this.cacheableMappingLocations != null) {
// Register given cacheable Hibernate mapping definitions, read from the file system.
for (int i = 0; i < this.cacheableMappingLocations.length; i++) {
config.addCacheableFile(this.cacheableMappingLocations[i].getFile());
}
}
if (this.mappingJarLocations != null) {
// Register given Hibernate mapping definitions, contained in jar files.
for (int i = 0; i < this.mappingJarLocations.length; i++) {
Resource resource = this.mappingJarLocations[i];
config.addJar(resource.getFile());
}
}
if (this.mappingDirectoryLocations != null) {
// Register all Hibernate mapping definitions in the given directories.
for (int i = 0; i < this.mappingDirectoryLocations.length; i++) {
File file = this.mappingDirectoryLocations[i].getFile();
if (!file.isDirectory()) {
throw new IllegalArgumentException(
"Mapping directory location [" + this.mappingDirectoryLocations[i] +
"] does not denote a directory");
}
config.addDirectory(file);
}
}
if (this.entityCacheStrategies != null) {
// Register cache strategies for mapped entities.
for (Enumeration classNames = this.entityCacheStrategies.propertyNames(); classNames.hasMoreElements();) {
String className = (String) classNames.nextElement();
String[] strategyAndRegion =
StringUtils.commaDelimitedListToStringArray(this.entityCacheStrategies.getProperty(className));
if (strategyAndRegion.length > 1) {
config.setCacheConcurrencyStrategy(className, strategyAndRegion[0], strategyAndRegion[1]);
}
else if (strategyAndRegion.length > 0) {
config.setCacheConcurrencyStrategy(className, strategyAndRegion[0]);
}
}
}
if (this.collectionCacheStrategies != null) {
// Register cache strategies for mapped collections.
for (Enumeration collRoles = this.collectionCacheStrategies.propertyNames(); collRoles.hasMoreElements();) {
String collRole = (String) collRoles.nextElement();
String[] strategyAndRegion =
StringUtils.commaDelimitedListToStringArray(this.collectionCacheStrategies.getProperty(collRole));
if (strategyAndRegion.length > 1) {
config.setCollectionCacheConcurrencyStrategy(collRole, strategyAndRegion[0], strategyAndRegion[1]);
}
else if (strategyAndRegion.length > 0) {
config.setCollectionCacheConcurrencyStrategy(collRole, strategyAndRegion[0]);
}
}
}
if (this.eventListeners != null) {
// Register specified Hibernate event listeners.
for (Iterator it = this.eventListeners.entrySet().iterator(); it.hasNext();) {
Map.Entry entry = (Map.Entry) it.next();
Assert.isTrue(entry.getKey() instanceof String, "Event listener key needs to be of type String");
String listenerType = (String) entry.getKey();
Object listenerObject = entry.getValue();
if (listenerObject instanceof Collection) {
Collection listeners = (Collection) listenerObject;
EventListeners listenerRegistry = config.getEventListeners();
Object[] listenerArray =
(Object[]) Array.newInstance(listenerRegistry.getListenerClassFor(listenerType), listeners.size());
listenerArray = listeners.toArray(listenerArray);
config.setListeners(listenerType, listenerArray);
}
else {
config.setListener(listenerType, listenerObject);
}
}
}
// Perform custom post-processing in subclasses.
postProcessConfiguration(config);
// Build SessionFactory instance.
logger.info("Building new Hibernate SessionFactory");
this.configuration = config;
return newSessionFactory(config);
}
finally {
if (dataSource != null) {
// Reset DataSource holder.
configTimeDataSourceHolder.set(null);
}
if (this.jtaTransactionManager != null) {
// Reset TransactionManager holder.
configTimeTransactionManagerHolder.set(null);
}
if (this.lobHandler != null) {
// Reset LobHandler holder.
configTimeLobHandlerHolder.set(null);
}
if (overrideClassLoader) {
// Reset original thread context ClassLoader.
currentThread.setContextClassLoader(threadContextClassLoader);
}
}
}