使用Spring AOP实现MySQL读写分离

Posted 2020-10-09 chuquan.ou

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.  
3. public class ChooseDataSource extends AbstractRoutingDataSource {
4.  
5. @Override
6. protected Object determineCurrentLookupKey() {
7. return HandleDataSource.getDataSource();
8. }
9. }

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.  
7. public static String getDataSource() {
8. return holder.get();
9. }
10. }

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.  
14. // @Before(value = "pointCut()")
15. public void before(JoinPoint point)
16. {
17. Object target = point.getTarget();
18. System.out.println(target.toString());
19. String method = point.getSignature().getName();
20. System.out.println(method);
21. Class<?>[] classz = target.getClass().getInterfaces();
22. Class<?>[] parameterTypes = ((MethodSignature) point.getSignature())
23. .getMethod().getParameterTypes();
24. try {
25. Method m = classz[0].getMethod(method, parameterTypes);
26. System.out.println(m.getName());
27. if (m != null && m.isAnnotationPresent(DataSource.class)) {
28. DataSource data = m.getAnnotation(DataSource.class);
29. HandleDataSource.putDataSource(data.value());
30. }
31.  
32. } catch (Exception e) {
33. e.printStackTrace();
34. }
35. }
36. }

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.  
17. <!-- 从库数据源 -->
18. <bean id="readDataSource" class="com.jolbox.bonecp.BoneCPDataSource" destroy-method="close">
19. <property name="driverClass" value="com.mysql.jdbc.Driver"/>
20. <property name="jdbcUrl" value="jdbc:mysql://172.22.14.7:3306/cpp?autoReconnect=true"/>
21. <property name="username" value="root"/>
22. <property name="password" value="root"/>
23. <property name="partitionCount" value="4"/>
24. <property name="releaseHelperThreads" value="3"/>
25. <property name="acquireIncrement" value="2"/>
26. <property name="maxConnectionsPerPartition" value="40"/>
27. <property name="minConnectionsPerPartition" value="20"/>
28. <property name="idleMaxAgeInSeconds" value="60"/>
29. <property name="idleConnectionTestPeriodInSeconds" value="60"/>
30. <property name="poolAvailabilityThreshold" value="5"/>
31. </bean>
32.  
33. <!-- transaction manager, 事务管理 -->
34. <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
35. <property name="dataSource" ref="dataSource" />
36. </bean>
37.  
38.  
39. <!-- 注解自动载入 -->
40. <context:annotation-config />
41.  
42. <!--enale component scanning (beware that this does not enable mapper scanning!)-->
43. <context:component-scan base-package="com.apc.cms.persistence.rdbms" />
44. <context:component-scan base-package="com.apc.cms.service">
45. <context:include-filter type="annotation"
46. expression="org.springframework.stereotype.Component" />
47. </context:component-scan>
48.  
49. <context:component-scan base-package="com.apc.cms.auth" />
50.  
51. <!-- enable transaction demarcation with annotations -->
52. <tx:annotation-driven />
53.  
54.  
55. <!-- define the SqlSessionFactory -->
56. <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
57. <property name="dataSource" ref="dataSource" />
58. <property name="typeAliasesPackage" value="com.apc.cms.model.domain" />
59. </bean>
60.  
61. <!-- scan for mappers and let them be autowired -->
62. <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
63. <property name="basePackage" value="com.apc.cms.persistence" />
64. <property name="sqlSessionFactory" ref="sqlSessionFactory" />
65. </bean>
66.  
67. <bean id="dataSource" class="com.apc.cms.utils.ChooseDataSource">
68. <property name="targetDataSources">
69. <map key-type="java.lang.String">
70. <!-- write -->
71. <entry key="write" value-ref="writeDataSource"/>
72. <!-- read -->
73. <entry key="read" value-ref="readDataSource"/>
74. </map>
75.  
76. </property>
77. <property name="defaultTargetDataSource" ref="writeDataSource"/>
78. </bean>
79.  
80. <!-- 激活自动代理功能 -->
81. <aop:aspectj-autoproxy proxy-target-class="true"/>
82.  
83. <!-- 配置数据库注解aop -->
84. <bean id="dataSourceAspect" class="com.apc.cms.utils.DataSourceAspect" />
85. <aop:config>
86. <aop:aspect id="c" ref="dataSourceAspect">
87. <aop:pointcut id="tx" expression="execution(* com.apc.cms.service..*.*(..))"/>
88. <aop:before pointcut-ref="tx" method="before"/>
89. </aop:aspect>
90. </aop:config>
91. <!-- 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.  
6. @DataSource("read")
7. public Document getDocById(long id) {
8. return documentMapper.getById(id);
9. }

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/