關于spring集成mybatis如何實現mysql數據庫讀寫分離的實例分析

#主數據庫數據源  jdbc.driverClassName=com.mysql.jdbc.Driver  jdbc.url=jdbc:mysql://192.168.0.4:3306/mybatis?useUnicode=true&characterEncoding=utf-8&useSSL=false  jdbc.username=root  jdbc.password=123456  jdbc.initialSize=1  jdbc.minIdle=1  jdbc.maxActive=20  jdbc.maxWait=60000  jdbc.removeAbandoned=true  jdbc.removeAbandonedTimeout=180  jdbc.timeBetweenEvictionRunsMillis=60000  jdbc.minEvictableIdleTimeMillis=300000  jdbc.validationQuery=SELECT?1  jdbc.testWhileIdle=true  jdbc.testOnBorrow=false  jdbc.testOnReturn=false  #從數據庫數據源  slave.jdbc.driverClassName=com.mysql.jdbc.Driver  slave.jdbc.url=jdbc:mysql://192.168.0.221:3306/mybatis?useUnicode=true&characterEncoding=utf-8&useSSL=false  slave.jdbc.username=root  slave.jdbc.password=123456  slave.jdbc.initialSize=1  slave.jdbc.minIdle=1  slave.jdbc.maxActive=20  slave.jdbc.maxWait=60000  slave.jdbc.removeAbandoned=true  slave.jdbc.removeAbandonedTimeout=180  slave.jdbc.timeBetweenEvictionRunsMillis=60000  slave.jdbc.minEvictableIdleTimeMillis=300000  slave.jdbc.validationQuery=SELECT?1  slave.jdbc.testWhileIdle=true  slave.jdbc.testOnBorrow=false  slave.jdbc.testOnReturn=false

<?xml  version="1.0" encoding="UTF-8"?><beans>  ??<!-- master數據源 -->  ??<bean>  ????<!-- 基本屬性 url、user、password -->?  ????<property></property>?  ????<property></property>?  ????<property></property>?  ????<property></property>?  ????<property></property>?  ????<property></property>??  ????<property></property>?  ????<property></property>  ????<!-- 超過時間限制是否回收 -->  ????<property></property>  ????<!-- 超過時間限制多長； -->  ????<property></property>  ????<!-- 配置間隔多久才進行一次檢測，檢測需要關閉的空閑連接，單位是毫秒 -->  ????<property></property>  ????<!-- 配置一個連接在池中最小生存的時間，單位是毫秒 -->  ????<property></property>  ????<!-- 用來檢測連接是否有效的sql，要求是一個查詢語句-->  ????<property></property>  ????<!-- 申請連接的時候檢測 -->  ????<property></property>  ????<!-- 申請連接時執行validationQuery檢測連接是否有效，配置為true會降低性能 -->  ????<property></property>  ????<!-- 歸還連接時執行validationQuery檢測連接是否有效，配置為true會降低性能 -->  ????<property></property>  ??</bean>  ??<!-- slave數據源 -->  ??<bean>  ????<property></property>?  ????<property></property>?  ????<property></property>?  ????<property></property>?  ????<property></property>?  ????<property></property>??  ????<property></property>?  ????<property></property>  ????<property></property>  ????<property></property>  ????<property></property>  ????<property></property>  ????<property></property>  ????<property></property>  ????<property></property>  ????<property></property>  ??</bean>  ??<!-- 動態數據源，根據service接口上的注解來決定取哪個數據源 -->  ??<bean>?  ????<property>???  ?????<map>???  ???????<!-- write or slave -->??  ???????<entry></entry>???  ???????<!-- read or master  -->?  ???????<entry></entry>???  ?????</map>????????  ????</property>??  ????<property></property>???  ??</bean>  ??<!-- Mybatis文件 -->  ??<bean>  ????<property></property>?  ????<property></property>  ????<!-- 映射文件路徑 -->  ????<property></property>  ??</bean>  ??<bean>  ????<property></property>  ????<property></property>  ??</bean>  ??<!-- 事務管理器 -->  ??<bean>  ????<property></property>  ??</bean>  ??<!-- 聲明式開啟 -->  ??<annotation-driven></annotation-driven>  ??<!-- 為業務邏輯層的方法解析@DataSource注解 為當前線程的HandleDataSource注入數據源 -->??  ??<bean></bean>??  ??<config>??  ????<aspect>??  ??????<pointcut></pointcut>??  ??????<before></before>????????  ????</aspect>??  ??</config></beans>

package?com.yzb.util;  import?java.lang.annotation.ElementType;  import?java.lang.annotation.Retention;  import?java.lang.annotation.RetentionPolicy;  import?java.lang.annotation.Target;  /**?  ?*?RUNTIME?  ?*?編譯器將把注釋記錄在類文件中，在運行時?VM?將保留注釋，因此可以反射性地讀取。?  ?*?  ?*/?  @Retention(RetentionPolicy.RUNTIME)?  @Target(ElementType.METHOD)?  public?@interface?DataSource  {  ??String?value();  }

package?com.yzb.util;  import?java.lang.reflect.Method;  import?org.aspectj.lang.JoinPoint;  import?org.aspectj.lang.reflect.MethodSignature;  public?class?DataSourceAspect  {  ??/**  ???*?在dao層方法獲取datasource對象之前，在切面中指定當前線程數據源  ???*/  ??public?void?before(JoinPoint?point)  ??{  ????Object?target?=?point.getTarget();  ????String?method?=?point.getSignature().getName();  ????Class>[]?classz?=?target.getClass().getInterfaces();????????????//?獲取目標類的接口，?所以@DataSource需要寫在接口上  ????Class>[]?parameterTypes?=?((MethodSignature)?point.getSignature())  ????????.getMethod().getParameterTypes();  ????try  ????{  ??????Method?m?=?classz[0].getMethod(method,?parameterTypes);  ??????if?(m?!=?null?&&?m.isAnnotationPresent(DataSource.class))  ??????{  ????????DataSource?data?=?m.getAnnotation(DataSource.class);  ????????System.out.println("用戶選擇數據庫庫類型："?+?data.value());  ????????HandleDataSource.putDataSource(data.value());????????????//?數據源放到當前線程中  ??????}  ????}?catch?(Exception?e)  ????{  ??????e.printStackTrace();  ????}  ??}  ??}

package?com.yzb.util;  import?org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;  public?class?DynamicDataSource?extends?AbstractRoutingDataSource  {  ??/**  ???*?獲取與數據源相關的key?此key是Map<string>?resolvedDataSources?中與數據源綁定的key值  ???*?在通過determineTargetDataSource獲取目標數據源時使用  ???*/  ??@Override  ??protected?Object?determineCurrentLookupKey()  ??{  ????return?HandleDataSource.getDataSource();  ??}  }</string>

package?com.yzb.util;  public?class?HandleDataSource  {  ??public?static?final?ThreadLocal<string>?holder?=?new?ThreadLocal<string>();  ??/**  ???*?綁定當前線程數據源  ???*?  ???*?@param?key  ???*/  ??public?static?void?putDataSource(String?datasource)  ??{  ????holder.set(datasource);  ??}  ??/**  ???*?獲取當前線程的數據源  ???*?  ???*?@return  ???*/  ??public?static?String?getDataSource()  ??{  ????return?holder.get();  ??}  }</string></string>

package?com.yzb.service;  import?java.util.List;  import?com.yzb.model.Person;  import?com.yzb.util.DataSource;  public?interface?IPersonService?{  ??/**  ???*?加載全部的person  ???*?@return  ???*/  ??List<person>?listAllPerson();  ??/**  ???*?查詢某個人的信息  ???*?@param?personId  ???*?@return  ???*/  ??@DataSource("slave")??????//?指定使用從數據源  ??Person?getPerson(int?personId);  ??boolean?updatePerson(Person?person);  }</person>