flea-db使用之JPA封装介绍

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.25</version>
</dependency>

<dependency>
    <groupId>org.eclipse.persistence</groupId>
    <artifactId>eclipselink</artifactId>
    <version>2.5.0</version>
</dependency>

public interface IAbstractFleaJPADAO<T> extends IFleaJPABaseDataHandler<T> {

}

public abstract class AbstractFleaJPADAOImpl<T> implements IAbstractFleaJPADAO<T> 

/**
    * <p> 获取T类型的Class对象 </p>
    *
    * @since 1.0.0
    */
public AbstractFleaJPADAOImpl() {
    // 获取泛型类的子类对象的Class对象
    Class<?> clz = getClass();
    // 获取子类对象的泛型父类类型（也就是AbstractDaoImpl<T>）
    ParameterizedType type = (ParameterizedType) clz.getGenericSuperclass();
    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("Type={}", type);
    }
    Type[] types = type.getActualTypeArguments();
    clazz = (Class<T>) types[0];
    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("ClassName={}", clazz.getName());
    }
}

protected abstract EntityManager getEntityManager();

public EntityManager getEntityManager(T entity) throws CommonException {
    return getEntityManager(entity, false);
}

private EntityManager getEntityManager(T entity, boolean flag) throws CommonException {
    EntityManager entityManager = getEntityManager();

    // 实体类设置默认库名
    setDefaultLibName(entity);

    // 处理并添加分表信息，如果不存在分表则不处理
    entityManager = LibTableSplitHelper.findTableSplitHandle().handle(entityManager, entity, flag);
    return entityManager;
}

protected FleaJPAQuery getQuery(Class result) {
    // 获取当前的持久化单元名
    String unitName = FleaEntityManager.getPersistenceUnitName(this.getClass().getSuperclass());
    FleaJPAQueryPool pool;
    if (StringUtils.isBlank(unitName)) {
        // 获取Flea JPA查询对象池 （使用默认对象池名"default"即可）
        pool = FleaObjectPoolFactory.getFleaObjectPool(FleaJPAQuery.class, FleaJPAQueryPool.class);
    } else {
        // 获取Flea JPA查询对象池 （使用持久化单元名unitName作为对象池名）
        pool = FleaObjectPoolFactory.getFleaObjectPool(unitName, FleaJPAQuery.class, FleaJPAQueryPool.class);
    }

    if (ObjectUtils.isEmpty(pool)) {
        throw new RuntimeException("Can not get a object pool instance");
    }

    // 获取Flea JPA查询对象实例
    FleaJPAQuery query = pool.getFleaObject();
    if (LOGGER.isDebugEnabled()) {
        Object obj = new Object() {};
        LOGGER.debug1(obj, "FleaJPAQueryPool = {}", pool);
        LOGGER.debug1(obj, "FleaJPAQuery = {}", query);
    }
    // 获取实例后必须调用该方法,对Flea JPA查询对象进行初始化
    query.init(getEntityManager(), entityClass, result);
    return query;
}

public interface IAbstractFleaJPASV<T> extends IFleaJPABaseDataHandler<T> {
}

    @Override
    public T query(long entityId) throws Exception {
        return getDAO().query(entityId);
    }

    // ... 其他接口实现已省略

    protected abstract IAbstractFleaJPADAO<T> getDAO();

public class FleaAuthDAOImpl<T> extends AbstractFleaJPADAOImpl<T> {

    @PersistenceContext(unitName="fleaauth")
    protected EntityManager entityManager;

    @Override
    @Transactional("fleaAuthTransactionManager")
    public boolean remove(long entityId) throws Exception {
        return super.remove(entityId);
    }
    
    // 其余代码省略。。。

    @Override
    protected EntityManager getEntityManager() {
        return entityManager;
    }

}

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">

    <persistence-unit name="fleaauth" transaction-type="RESOURCE_LOCAL">
        <!-- provider -->
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <!-- Connection JDBC -->
        <class>具体实体类全名</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>

        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/fleaauth?useUnicode=true&amp;characterEncoding=UTF-8" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="root" />
        </properties>
    </persistence-unit>
</persistence>

<bean id="defaultPersistenceManager" class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
	<property name="persistenceXmlLocations">
		<!-- 可以配置多个持久单元 -->
		<list>
			<value>classpath:META-INF/fleaauth-persistence.xml</value>
		</list>
	</property>
</bean>
<bean id="defaultPersistenceProvider" class="org.eclipse.persistence.jpa.PersistenceProvider"/>
<bean id="defaultLoadTimeWeaver" class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/>
<bean id="defaultVendorAdapter" class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">
	<!-- 是否在控制台显示sql -->
	<property name="showSql" value="true"/>
</bean>
<bean id="defaultJpaDialect" class="org.springframework.orm.jpa.vendor.EclipseLinkJpaDialect"/>

<!-- 以下部分 与指定持久化单元一一对应 -->
<!-- ################# -->
<!-- FleaAuth TransAction Manager JPA -->
<!-- ################# -->
<bean id="fleaAuthEntityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
	<property name="persistenceUnitManager" ref="defaultPersistenceManager"/>
	<property name="persistenceUnitName" value="fleaauth"/>
	<property name="persistenceProvider" ref="defaultPersistenceProvider"/>
	<property name="jpaVendorAdapter" ref="defaultVendorAdapter"/>
	<property name="jpaDialect" ref="defaultJpaDialect"/>
	<property name="jpaPropertyMap">
		<map>
			<entry key="eclipselink.weaving" value="false"/>
		</map>
	</property>
</bean>

<bean id="fleaAuthTransactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
	<property name="entityManagerFactory" ref="fleaAuthEntityManagerFactory"/>
</bean>

<tx:annotation-driven transaction-manager="fleaAuthTransactionManager"/>