spring 中的事务小结

spring中可以使用声明式事务和编程式事务，主要用的比较多的是声明式事务，下面举例子小结一下
首先在config.xml中定义好datasource和platformtranscationmanager
<!-- 定义DataSource -->

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">

..........
</bean>

<!-- 定义TransactionManager -->

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager" >
<property name="dataSource" ref="dataSource" />
</bean>

<!-- 定义BookDao -->

<bean id="bookDaoTarget" class="example.chapter6.BookDaoImpl">
<property name="dataSource" ref="dataSource" />
</bean>

<!-- 封装为事务的BookDao -->

<bean id="bookDao" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="target" ref="bookDaoTarget" />
<property name="transactionManager" ref="transactionManager" />
<property name="transactionAttributes">
<props>
<!-- 对以query开头的方法要求只读事务 -->
<prop key="query*">PROPAGATION_REQUIRED,readOnly</prop>
<!-- 对于其他方法要求事务 -->
<prop key="*">PROPAGATION_REQUIRED</prop>
</props>
</property>

则使用的代码例子为
ApplicationContext context = new ClassPathXmlApplicationContext("config.xml");
BookDao bookDao = (BookDao)context.getBean("bookDao");
.....//之后的就是
try
{

}catch {}结构，程序中不需要再有处理事务方面的代码了。

另外，在JAVA 5中，可以用注释来更简单的配置，但要注意的是，必须使用spring 2.0才行
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-2.0.xsd"
>
。。。。。。其他的和上面的相同，最后加上
<!-- 将所有具有@Transactional注解的Bean自动配置为声明式事务支持 -->
<tx:annotation-driven transaction-manager="transactionManager"/>

然后，对接口使用注释
import org.springframework.transaction.annotation.Transactional;

@Transactional
public interface BookDao {

@Transactional(readOnly=true)
Book query(String id);

@Transactional(readOnly=true)
List<Book> queryAll();

void insert(Book book);

void update(Book book);

void delete(Book book);

}
要注意的是，@transcational的注释只能应用到public方法上

2 集成hiberante事务
比如用hibernatedaosupport支持DAO，使用spring 2.0的注解,比如

bookdao.java
import org.springframework.transaction.annotation.Transactional;

@Transactional
public interface BookDao {

@Transactional(readOnly=true)
Book query(String id);

@Transactional(readOnly=true)
List<Book> queryAll();

void insert(Book book);

void update(Book book);

void delete(Book book);

}

实体配置代码如下

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity(name="Book")
public class Book {

private String id;
private String name;
private String author;

@Id
public String getId() { return id; }
public void setId(String id) { this.id = id; }

public String getName() { return name; }
public void setName(String name) { this.name = name; }

public String getAuthor() { return author; }
public void setAuthor(String author) { this.author = author; }

}
然后其配置代码如下
<!-- 定义SessionFactory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource"/>
</property>
<property name="annotatedClasses">
<list>
<value>example.chapter6.Book</value>
</list>
</property>
<property name="annotatedPackages">
<list>
<value>example.chapter6</value>
</list>
</property>
</bean>

<!-- 定义TransactionManager -->
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager" >
<property name="sessionFactory" ref="sessionFactory" />
</bean>

<!-- 定义BookDao -->
<bean id="bookDao" class="example.chapter6.BookDaoImpl">
<property name="sessionFactory" ref="sessionFactory" />
</bean>

<!-- 将所有具有@Transactional注解的Bean自动配置为声明式事务支持 -->
<tx:annotation-driven transaction-manager="transactionManager"/>