使用Spring AOP实现MySQL读写分离

spring aop ， mysql 主从配置 实现读写分离，下来把自己的配置过程，以及遇到的问题记录下来，方便下次操作，也希望给一些朋友带来帮助。
mysql主从配置参看：http://blog.csdn.net/huoyunshen88/article/details/26597483
1.使用spring aop 拦截机制现数据源的动态选取。

1. @Retention(RetentionPolicy.RUNTIME)
2. @Target(ElementType.METHOD)
3. public @interface DataSource {
4. String value();
5. }

3.利用Spring的AbstractRoutingDataSource解决多数据源的问题 参考本站《使用Spring的AbstractRoutingDataSource解决多数据源的问题》

1. import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
2. public class ChooseDataSource extends AbstractRoutingDataSource {
3. @Override
4. protected Object determineCurrentLookupKey() {
5. return HandleDataSource.getDataSource();
6. }
7. }

4.利用ThreadLocal解决线程安全问题

1. public class HandleDataSource {
2. public static final ThreadLocal<String> holder = new ThreadLocal<String>();
3. public static void putDataSource(String datasource) {
4. holder.set(datasource);
5. }
6. public static String getDataSource() {
7. return holder.get();
8. }
9. }

5.定义一个数据源切面类，通过aop访问，在spring配置文件中配置了，所以没有使用aop注解

1. import java.lang.reflect.Method;
2. import org.aspectj.lang.JoinPoint;
3. import org.aspectj.lang.annotation.Aspect;
4. import org.aspectj.lang.annotation.Before;
5. import org.aspectj.lang.annotation.Pointcut;
6. import org.aspectj.lang.reflect.MethodSignature;
7. import org.springframework.stereotype.Component;
8. //@Aspect
9. //@Component
10. public class DataSourceAspect {
11. //@Pointcut("execution(* com.apc.cms.service.*.*(..))")
12. public void pointCut(){};
13. // @Before(value = "pointCut()")
14. public void before(JoinPoint point)
15. {
16. Object target = point.getTarget();
17. System.out.println(target.toString());
18. String method = point.getSignature().getName();
19. System.out.println(method);
20. Class<?>[] classz = target.getClass().getInterfaces();
21. Class<?>[] parameterTypes = ((MethodSignature) point.getSignature())
22. .getMethod().getParameterTypes();
23. try {
24. Method m = classz[0].getMethod(method, parameterTypes);
25. System.out.println(m.getName());
26. if (m != null && m.isAnnotationPresent(DataSource.class)) {
27. DataSource data = m.getAnnotation(DataSource.class);
28. HandleDataSource.putDataSource(data.value());
29. }
30. } catch (Exception e) {
31. e.printStackTrace();
32. }
33. }
34. }

6.配置applicationContext.xml

1. <!-- 主库数据源 -->
2. <bean id="writeDataSource" class="com.jolbox.bonecp.BoneCPDataSource" destroy-method="close">
3. <property name="driverClass" value="com.mysql.jdbc.Driver"/>
4. <property name="jdbcUrl" value="jdbc:mysql://172.22.14.6:3306/cpp?autoReconnect=true"/>
5. <property name="username" value="root"/>
6. <property name="password" value="root"/>
7. <property name="partitionCount" value="4"/>
8. <property name="releaseHelperThreads" value="3"/>
9. <property name="acquireIncrement" value="2"/>
10. <property name="maxConnectionsPerPartition" value="40"/>
11. <property name="minConnectionsPerPartition" value="20"/>
12. <property name="idleMaxAgeInSeconds" value="60"/>
13. <property name="idleConnectionTestPeriodInSeconds" value="60"/>
14. <property name="poolAvailabilityThreshold" value="5"/>
15. </bean>
16. <!-- 从库数据源 -->
17. <bean id="readDataSource" class="com.jolbox.bonecp.BoneCPDataSource" destroy-method="close">
18. <property name="driverClass" value="com.mysql.jdbc.Driver"/>
19. <property name="jdbcUrl" value="jdbc:mysql://172.22.14.7:3306/cpp?autoReconnect=true"/>
20. <property name="username" value="root"/>
21. <property name="password" value="root"/>
22. <property name="partitionCount" value="4"/>
23. <property name="releaseHelperThreads" value="3"/>
24. <property name="acquireIncrement" value="2"/>
25. <property name="maxConnectionsPerPartition" value="40"/>
26. <property name="minConnectionsPerPartition" value="20"/>
27. <property name="idleMaxAgeInSeconds" value="60"/>
28. <property name="idleConnectionTestPeriodInSeconds" value="60"/>
29. <property name="poolAvailabilityThreshold" value="5"/>
30. </bean>
31. <!-- transaction manager, 事务管理 -->
32. <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
33. <property name="dataSource" ref="dataSource" />
34. </bean>
35. <!-- 注解自动载入 -->
36. <context:annotation-config />
37. <!--enale component scanning (beware that this does not enable mapper scanning!)-->
38. <context:component-scan base-package="com.apc.cms.persistence.rdbms" />
39. <context:component-scan base-package="com.apc.cms.service">
40. <context:include-filter type="annotation"
41. expression="org.springframework.stereotype.Component" />
42. </context:component-scan>
43. <context:component-scan base-package="com.apc.cms.auth" />
44. <!-- enable transaction demarcation with annotations -->
45. <tx:annotation-driven />
46. <!-- define the SqlSessionFactory -->
47. <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
48. <property name="dataSource" ref="dataSource" />
49. <property name="typeAliasesPackage" value="com.apc.cms.model.domain" />
50. </bean>
51. <!-- scan for mappers and let them be autowired -->
52. <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
53. <property name="basePackage" value="com.apc.cms.persistence" />
54. <property name="sqlSessionFactory" ref="sqlSessionFactory" />
55. </bean>
56. <bean id="dataSource" class="com.apc.cms.utils.ChooseDataSource">
57. <property name="targetDataSources">
58. <map key-type="java.lang.String">
59. <!-- write -->
60. <entry key="write" value-ref="writeDataSource"/>
61. <!-- read -->
62. <entry key="read" value-ref="readDataSource"/>
63. </map>
64. </property>
65. <property name="defaultTargetDataSource" ref="writeDataSource"/>
66. </bean>
67. <!-- 激活自动代理功能 -->
68. <aop:aspectj-autoproxy proxy-target-class="true"/>
69. <!-- 配置数据库注解aop -->
70. <bean id="dataSourceAspect" class="com.apc.cms.utils.DataSourceAspect" />
71. <aop:config>
72. <aop:aspect id="c" ref="dataSourceAspect">
73. <aop:pointcut id="tx" expression="execution(* com.apc.cms.service..*.*(..))"/>
74. <aop:before pointcut-ref="tx" method="before"/>
75. </aop:aspect>
76. </aop:config>
77. <!-- 配置数据库注解aop -->

7.使用注解，动态选择数据源，分别走读库和写库

1. @DataSource("write")
2. public void update(User user) {
3. userMapper.update(user);
4. }
5. @DataSource("read")
6. public Document getDocById(long id) {
7. return documentMapper.getById(id);
8. }

测试写操作：可以通过应用修改数据，修改主库数据，发现从库的数据被同步更新了，所以定义的write操作都是走的写库
测试读操作：
后台修改从库数据，查看主库的数据没有被修改，在应用页面中刷新，发现读的是从库的数据，说明读写分离ok。

http://www.sunyaozong.com/mysql-read-write-sepreate-solution-by-spring-aop/