Dao 的支持类可以有好多，如： JdbcDaoSupport ， HibernateDaoSupport ，JdoDaoSupport等，下面对最常用的HibernateDaoSupport与JdbcDaoSupport做一小总结：

一、在Spring框架中实现连接数据库方式：
1、、借助类HibernateDaoSupport的简约化实现：
借助这个类必须需要HIbernate框架，用到HIbernate里提供的HibernateTemplate模板，从而进行增、删、改、查操作。
TestA.java:
public class TestA extends HibernateDaoSupport{
public void test(){
     HibernateTemplate template = this.getHibernateTemplate();
     List list = template.find("from User");
     for(int i=0;i<list.size();i++){
      User u = (User)list.get(i);
      System.out.println(u.getUserid()+" "+u.getEmail());
     }
}
public static void main(String[] args) {
           ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
           TestA t = (TestA)ctx.getBean("testa");
           t.test();
}
}
需要在Spring的配置文件applicationContext.xml中控制反转用到连接数据库中的类是注入SessionsFactory，如下：
applicationContext.xml:
        <bean id="testa" class="com.sun.demo.TestA">
        <property name="sessionFactory">
        <ref bean="mySessionFactory"/>
        </property>
        </bean>
2、、借助类JdbcDaoSupport的简约化实现：
借助这个类不需要HIbernate框架，也不需要有ORM的对象关联映射。但它和HibernateDaoSupport很类似，有JdbcTemplate来实现增、删、改、查操作。
TestA.java:
public class TestA extends JdbcDaoSupport{
    public void test(){
        int n = this.getJdbcTemplate().queryForInt("select max(userid) from User");
        System.out.println(n);
    }
public static void main(String[] args) {
ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
TestA ta = (TestA)ctx.getBean("testa");
        ta.test();
}
}
需要在Spring的配置文件applicationContext.xml中控制反转用到连接数据库中的类是注入DataSource，如下：
applicationContext.xml:
        <bean id="testa" class="com.sun.demo.TestA">
        <property name="dataSource">
        <ref bean="myDataSource"/>
        </property>
        </bean>
       
二、编程式事务管理、声明式事务管理中HibernateDaoSupport与JdbcDaoSupport的应用：
1、编程式事务管理：
1>、JdbcDaoSupport编程式事物管理，必须继承JdbcDaoSupport类，得到JdbcTemplate从而实现事务管理；
TestA.java:
public class TestA extends JdbcDaoSupport{
public void test(){
     PlatformTransactionManager ptm = new DataSourceTransactionManager(this.getDataSource());
     TransactionTemplate tst = new TransactionTemplate(ptm);
     tst.execute(new TransactionCallback(){
   public Object doInTransaction(TransactionStatus status) {
      getJdbcTemplate().update("update User set password='1230' where userid='1001'");
      getJdbcTemplate().update("update User set where userid='100000001'");
      getJdbcTemplate().update("update User set phone='phone'");
      return null;
   }
     });
}
public static void main(String[] args) {
    ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
    TestA t = (TestA)ctx.getBean("testa");
    t.test();
}
}
需要在Spring的配置文件applicationContext.xml中控制反转用到连接数据库中的类是注入DataSource，如下：
applicationContext.xml:
<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
   
    ... ...
   
    <property name="defaultAutoCommit">
    <value>false</value>
    </property>
</bean>
   
        <bean id="testa" class="com.sun.demo.TestA">
        <property name="dataSource">
        <ref bean="myDataSource"/>
        </property>
        </bean>
2>、HibernateDaoSupport编程式事物管理，必须继承HibernateDaoSupport类，得到HibernateTemplate从而实现事务管理；
TestB.java:
public class TestB extends HibernateDaoSupport{
public void test(){
     HibernateTransactionManager hm = new HibernateTransactionManager(this.getSessionFactory());
     TransactionTemplate ttm = new TransactionTemplate(hm);
     ttm.execute(new TransactionCallback(){
   public Object doInTransaction(TransactionStatus status) {
    User u1 = new User();
    u1.setUserid("3001");
    u1.setPassword("3001");
    getHibernateTemplate().save(u1);
   
    User u2 = new User();
    u2.setUserid("3001");
    u2.setPassword("3002");
    getHibernateTemplate().save(u2);
    return null;
   }
     });
}
public static void main(String[] args) {
           ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
           TestB t = (TestB)ctx.getBean("testb");
        t.test();
}
}
需要在Spring的配置文件applicationContext.xml中控制反转用到连接数据库中的类是注入SessionsFactory，如下：
applicationContext.xml:
<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
   
    ... ...
   
    <property name="defaultAutoCommit">
    <value>false</value>
    </property>
</bean>
   
     <bean id="testb" class="com.sun.demo.TestB">
     <property name="sessionFactory">
     <ref bean="mySessionFactory"/>
     </property>
     </bean>
2、声明式事务管理：   
1>、JdbcDaoSupport声明式样事物管理,必须继承JdbcDaoSupport类；
<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
        
         ... ....
<property name="defaultAutoCommit">
<value>false</value>
</property>
</bean>
   需要在Spring配置文件中配置声明事务处理，用JdbcDaoSupport提供的DataSourceTransactionManager如下：
        <!-- 事务管理配置 -->
        <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource">
        <ref bean="myDataSource"/>
        </property>
        </bean>
      
        <bean id="baseTransactionProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
        <property name="transactionManager" ref="transactionManager"/>
        <!-- 事务管理属性 -->
        <property name="transactionAttributes">
           <props>
           <prop key="updateUser">PROPAGATION_REQUIRED</prop>
           </props>
        <!-- 事务管理目标bean -->
        </property>
        <property name="target" ref="userdao"></property>
        </bean>
       
        <bean id="userdao" class="com.sun.demo.UserDao">
        <property name="dataSource">
        <ref bean="myDataSource"/>
        </property>
        </bean>

IUserDao.java://定义接口

public interface IUserDao {
public void updateUser();
}

UserDao.java:

public class UserDao extends JdbcDaoSupport implements IUserDao{
       public void updateUser(){
        this.getJdbcTemplate().update("update User set password='password1' where userid='1001'");
           this.getJdbcTemplate().update("update User set password='password9999999999999999999999999999999' where userid='1002'");
       }
}

TestA.java://调用updateUser()方法

public class{
   
    public void test(){
          ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
       IUserDao u = (IUserDao)ctx.getBean("baseTransactionProxy");
          u.updateUser();
    }
public static void main(String[] args) {
           TestA t = new TestA();
           t.test();
}
}
2>、HibernateDaoSupport声明式事物管理，必须继承HibernateDaoSupport类；
IUserDao.java://定义接口
public interface IUserDao {
public void updateUser();
}
UserDao.java:
public class UserDao extends HibernateDaoSupport implements IUserDao{
       public void updateUser(){
              User u1 = new User();
              u1.setUserid("1001");
              u1.setPassword("5001");
              this.getHibernateTemplate().update(u1);
             
             
              User u2 = new User();
              u2.setUserid("1003");
              u2.setPassword("20015555555555555555555555555555555555555555555");
              this.getHibernateTemplate().update(u2);
       }
}

测试：

public class TestA{
   
    public void test(){
          ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
       IUserDao userdao= (IUserDao)ctx.getBean("userproxy");
          userdao.updateUser();
    }
public static void main(String[] args) {
           TestA t = new TestA();
           t.test();
}
}
需要在Spring配置文件中配置声明事务处理，用JdbcDaoSupport提供的HibernateTransactionManager如下：
applicationContext.xml:
        <!-- 事务管理配置 -->
        <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory">
        <ref bean="mySessionFactory"/>
        </property>
        </bean>
       
        <bean id="baseTransactionProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract="true">
        <property name="transactionManager" ref="transactionManager"/>
        <!-- 事务管理属性 -->
        <property name="transactionAttributes">
           <props>
           <prop key="update*">PROPAGATION_REQUIRED</prop>
           <prop key="save*">PROPAGATION_REQUIRED</prop>
           <prop key="delete*">PROPAGATION_REQUIRED</prop>
           </props>
        <!-- 事务管理目标bean -->      
        </property>
        </bean>
       
        <bean id="userdao" class="com.sun.demo.UserDao">
        <property name="sessionFactory">
        <ref bean="mySessionFactory"/>
        </property>
        </bean>
       
        <bean id="userproxy" parent="baseTransactionProxy">
        <property name="target" ref="userdao"></property>
        </bean>