總結
- 聲明式事務:非侵入式,本質是AOP,推薦!
- 編程式事務:侵入式,需要在代碼中調用 commit()、rollback()等事務管方法,還需要在代碼中通過try catch,不推薦!
①編程式事務管理使用TransactionTemplate。
②聲明式事務管理建立在AOP之上的。其本質是通過AOP功能,對方法前后進行攔截,將事務處理的功能編織到攔截的方法中,也就是在目標方法開始之前啟動一個事務,在執行完目標方法之后根據執行情況提交或者回滾事務。
聲明式事務最大的優點就是不需要在業務邏輯代碼中摻雜事務管理的代碼,只需在配置文件中做相關的事務規則聲明或通過@Transactional注解的方式,便可以將事務規則應用到業務邏輯中,減少業務代碼的污染。
唯一不足地方是,最細粒度只能作用到方法級別,無法做到像編程式事務那樣可以作用到代碼塊級別。
一、聲明式事務配置(XML方式)
1-pom文件中,添加 AOP Aspectj 的支持
maven pom.xml 添加 Aspectj 的支持
<dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.13</version> </dependency>
2-准備給deleteUser()增加事務操作
package constxiong.interview.transaction; import java.util.List; import java.util.Map; import org.springframework.jdbc.core.support.JdbcDaoSupport; public class UserDaoImpl extends JdbcDaoSupport implements UserDao { /** * 查詢用戶 * @return */ public List<Map<String, Object>> getUsers() { String sql = "select * from user"; return this.getJdbcTemplate().queryForList(sql); } /** * 刪除用戶 * @param id * @return */ //@Transactional(rollbackFor=RuntimeException.class) public int deleteUser(int id){ String sql = "delete from user where id = " + id; int result = this.getJdbcTemplate().update(sql); if (id == 1) { throw new RuntimeException(); } return result; } }
3-Spring配置文件中,配置聲明式事務管理器 DataSourceTransactionManager
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <bean id="driver" class="com.mysql.jdbc.Driver"></bean> <bean id="datasource" class="org.springframework.jdbc.datasource.SimpleDriverDataSource"> <constructor-arg index="0" name="driver" ref="driver" /> <constructor-arg index="1"> <value>jdbc:mysql://localhost:3306/test</value> </constructor-arg> <constructor-arg index="2"> <value>root</value> </constructor-arg> <constructor-arg index="3"> <value>root</value> </constructor-arg> </bean> <bean id="userDao" class="constxiong.interview.transaction.UserDaoImpl"> <property name="dataSource" ref="datasource"></property> </bean> <!-- 事務管理器 --> <bean id="tracnsactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="datasource"></property> </bean> </beans>
4-配置事務通知 ,“確定為哪個/哪些方法配置事務”
注意:<tx:method name="add*"> 表示事務會在所有以add開頭的方法上,例如addUser(), addGoods()等
<tx:advice id="txAdvice" transaction-manager="tracnsactionManager"> <tx:attributes> <!-- 為連接點指定事務屬性 --> <tx:method name="deleteUser" rollback-for="java.lang.RuntimeException"/> </tx:attributes> </tx:advice>
另一個例子:
5-配置事務切入,“確定切入點(哪個類)”
<aop:config> <!-- 切入點配置 --> <aop:pointcut id="point" expression="execution(* *constxiong.interview.transaction.UserDao.deleteUser(..))" /> <aop:advisor advice-ref="txAdvice" pointcut-ref="point"/>
另一個例子:
6-測試
package constxiong.interview.transaction; import java.util.Map; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class TransactionTest { static ApplicationContext context = new ClassPathXmlApplicationContext("spring_transaction.xml"); public static void main(String[] args) throws Exception { testAspectjTransaction(); } private static void testAspectjTransaction() { UserDao userDao = (UserDao)context.getBean("userDao"); printUsers(userDao); userDao.deleteUser(1); } private static void printUsers(UserDao userDao) { for (Map<String, Object> user : userDao.getUsers()) { System.out.println(user); } } }
輸出結果
{id=1, username=user1} {id=2, username=user2} Exception in thread "main" java.lang.RuntimeException at constxiong.interview.transaction.UserDaoImpl.deleteUser(UserDaoImpl.java:28) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208) at com.sun.proxy.$Proxy2.deleteUser(Unknown Source) at constxiong.interview.transaction.TransactionTest.testAnnotationTransaction(TransactionTest.java:20) at constxiong.interview.transaction.TransactionTest.main(TransactionTest.java:13)
二、聲明式事務配置(@Transactional注解方式)
和XML方式相比,有以下不一樣的點
1-在deleteUser()上增加@Transactional注解
package constxiong.interview.transaction; import java.util.List; import java.util.Map; import org.springframework.jdbc.core.support.JdbcDaoSupport; import org.springframework.transaction.annotation.Transactional; public class UserDaoImpl extends JdbcDaoSupport implements UserDao { /** * 查詢用戶 * @return */ public List<Map<String, Object>> getUsers() { String sql = "select * from user"; return this.getJdbcTemplate().queryForList(sql); } /** * 刪除用戶 * @param id * @return */ @Transactional(rollbackFor=RuntimeException.class) public int deleteUser(int id){ String sql = "delete from user where id = " + id; int result = this.getJdbcTemplate().update(sql); if (id == 1) { throw new RuntimeException(); } return result; } }
2-pom文件里,啟用事務注解
同時,刪除“切點”“切面”的配置
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <bean id="driver" class="com.mysql.jdbc.Driver"></bean> <bean id="datasource" class="org.springframework.jdbc.datasource.SimpleDriverDataSource"> <constructor-arg index="0" name="driver" ref="driver" /> <constructor-arg index="1"> <value>jdbc:mysql://localhost:3306/test</value> </constructor-arg> <constructor-arg index="2"> <value>root</value> </constructor-arg> <constructor-arg index="3"> <value>root</value> </constructor-arg> </bean> <bean id="userDao" class="constxiong.interview.transaction.UserDaoImpl"> <property name="dataSource" ref="datasource"></property> </bean> <!-- 事務管理器 --> <bean id="tracnsactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="datasource"></property> </bean> <!-- 啟用事務注解 --> <tx:annotation-driven transaction-manager="tracnsactionManager"/> </beans>
三、編程式事務
1-pom引入driver和DataSource
可以通過 java.sql.Connection 控制事務
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <bean id="driver" class="com.mysql.jdbc.Driver"></bean> <bean id="datasource" class="org.springframework.jdbc.datasource.SimpleDriverDataSource"> <constructor-arg index="0" name="driver" ref="driver" /> <constructor-arg index="1"> <value>jdbc:mysql://localhost:3306/test</value> </constructor-arg> <constructor-arg index="2"> <value>root</value> </constructor-arg> <constructor-arg index="3"> <value>root</value> </constructor-arg> </bean> </beans>
2-編程式事務內核:在代碼中侵入式控制事務
package constxiong.interview.transaction; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.sql.DataSource; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class TransactionTest { public static void main(String[] args) throws Exception { testManualTransaction();//測試函數式控制事務 } private static void testManualTransaction() throws SQLException { ApplicationContext context = new ClassPathXmlApplicationContext("spring_transaction.xml"); DataSource ds = (DataSource)context.getBean("datasource"); Connection conn = ds.getConnection(); try { initTable(conn);//初始化表 conn.setAutoCommit(false);//設置不自動提交事務 queryUsers(conn);//查詢打印用戶表 deleteUser(conn);//刪除 id=1 用戶 conn.rollback();//回滾 queryUsers(conn);//查詢打印用戶表 } finally { conn.close(); } } private static void initTable(Connection conn) throws SQLException { conn.createStatement().execute("drop table if exists user"); conn.createStatement().execute("create table user(id int, username varchar(60)) ENGINE=InnoDB DEFAULT CHARSET=utf8 ");//是否支持事務與數據庫引擎有關,此處刪除 ENGINE=InnoDB DEFAULT CHARSET=utf8 可能不支持事務 conn.createStatement().execute("insert into user values(1, 'user1')"); conn.createStatement().execute("insert into user values(2, 'user2')"); } private static void deleteUser(Connection conn) throws SQLException { conn.createStatement().execute("delete from user where id = 1"); } private static void queryUsers(Connection conn) throws SQLException { Statement st = conn.createStatement(); st.execute("select * from user"); ResultSet rs = st.getResultSet(); while (rs.next()) { System.out.print(rs.getString("id")); System.out.print(" "); System.out.print(rs.getString("username")); System.out.println(); } } }
刪除用戶語句回滾,打印出兩個用戶
1 user1 2 user2 1 user1 2 user2