Hibernate访问多个数据库

Hibernate访问多个数据库

Hibernate访问多个数据库的设计思路：利用 Hibernate中config = new Configuration().configure(configFile);可以加载不同数据库配置信息的原理，编写一个数据库操作类，再编写一个数据库管理程序[map]，将加载的数据库连接实例put早数据库管理程序中，具体实现见下面：

Hibernate访问多个数据库步骤一：hibernate配置文件

localhost.cfg.xml

< ?xml version="1.0" encoding="utf-8"?>
< !DOCTYPE hibernate-configuration
     PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
     "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

< hibernate-configuration>
    < session-factory >

  < !-- local connection properties -->
  < property name="hibernate.connection.url">jdbc:mysql://localhost:3306/bookshop?zeroDateTimeBehavior=convertToNull< /property>
  < property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver< /property>
  < property name="hibernate.connection.username">root< /property>
  < property name="hibernate.connection.password">12345678< /property>
  < !-- property name="hibernate.connection.pool_size">< /property -->

  < !-- dialect for MySQL -->
        < property name="dialect">org.hibernate.dialect.MySQLDialect< /property>

        < property name="hibernate.show_sql">true< /property>
        < property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory< /property>
        < property name="hbm2ddl.auto">update< /property>

     < mapping resource="org/jskyme/data/local/po/Shop.hbm.xml"/>
    < /session-factory>
< /hibernate-configuration>

data_server.cfg.xml

< ?xml version="1.0" encoding="utf-8"?>

< !DOCTYPE hibernate-configuration

     PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"

     "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

< hibernate-configuration>

    < session-factory >

  < !-- local connection properties -->

  < property name="hibernate.connection.url">jdbc:mysql://192.168.0.10:3306/bookshop?zeroDateTimeBehavior=convertToNull< /property>

  < property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver< /property>

  < property name="hibernate.connection.username">root< /property>

  < property name="hibernate.connection.password">12345678< /property>

  < !-- property name="hibernate.connection.pool_size">< /property -->

  < !-- dialect for MySQL -->

        < property name="dialect">org.hibernate.dialect.MySQLDialect< /property>

        < property name="hibernate.show_sql">true< /property>

        < property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory< /property>

        < property name="hbm2ddl.auto">update< /property>

     < mapping resource="org/jskyme/data/local/po/Shop.hbm.xml"/>

    < /session-factory>

< /hibernate-configuration>

Hibernate访问多个数据库步骤二：数据库访问类：

数据库管理类：DataBaseManager

package org.jskyme.hibernate.util;

import java.util.HashMap;

public class DataBaseManager extends HashMap {
 private static final long serialVersionUID = 6491666983237498097L;
 private static DataBaseManager inst = new DataBaseManager();

 public static DataBaseManager getInst() {
  return inst;
 }

 public SessionManager get(Object key) {
  return (SessionManager) super.get(key);
 }

 @Override
 public Object put(Object key, Object value) {
  return super.put(key, value);
 }

 public static void setInst(DataBaseManager inst) {
   DataBaseManager.inst = inst;
 }

}

Hibernate连接数据库操作类：

package org.jskyme.hibernate.util;

import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public final class SessionManager {
 private Configuration config;

 private SessionFactory sessionFactory;

 private Session session;

 public Criteria createCriteria(Class persistentClass) {
  return session.createCriteria(persistentClass);
 }

 private void buildSession() {
   sessionFactory = config.buildSessionFactory();
   session = sessionFactory.openSession();
 }

 public SessionManager(String configFile) {
   config = new Configuration().configure(configFile);
   buildSession();
 }

 public Session getSession() {
  return session;
 }

 public void save(Object obj) {
   Transaction tx = session.beginTransaction();
   session.save(obj);
   tx.commit();
 }

 public Object load(Class clas, Integer priId) {
  return session.get(clas, priId);
 }

 public Query findbyhql(String hql) {
  return session.createQuery(hql);
 }

 public List pageSizeByhql(String hql) {
  return findbyhql(hql).list();
 }

 public SQLQuery findbysql(String sql) {
  return session.createSQLQuery(sql);
 }

 public void update(Object obj) {
   Transaction tx = session.beginTransaction();
   session.saveOrUpdate(obj);
   tx.commit();
 }
 public void delete(Class clas, Integer inte) {
   session.delete(load(clas, inte));
 }

 public void delete(Object obj) {
   session.delete(obj);
 }

 public void deletebyhql(String hql) {
   Query query = session.createQuery(hql);
   query.executeUpdate();
 }

 public Query createQuery(String hql) {
  return session.createQuery(hql);
 }

}

Hibernate访问多个数据库步骤三：测试类

package org.jskyme.data.test;

import junit.framework.TestCase;

import org.hibernate.Query;
import org.jskyme.hibernate.util.DataBaseManager;
import org.jskyme.hibernate.util.SessionManager;

public class DataBaseManagerTest extends TestCase {
DataBaseManager dbm = DataBaseManager.getInst();

public void testDatabase() {
   setDatabase();
   SessionManager tempSess = dbm.get("dataLocal");
   Query query = tempSess.createQuery("from   Shop");
   query.list();

   SessionManager tempSess27 = dbm.get("dateManage");
   Query query27 = tempSess27.createQuery("from Shop");
   query27.list();
}

private void setDatabase() {
   SessionManager dateManageLocal = new SessionManager("localhost.cfg.xml");
   SessionManager dateManage27 = new SessionManager("data_server.cfg.xml");
   dbm.put("dateManage", dateManage27);
   dbm.put("dataLocal", dateManageLocal);

}
}