spring 解析之切換數(shù)據(jù)源-mysql實現(xiàn)版本

java探案

2017-06-08 13:13:26

主要思想：自定義一個注解,此注解標(biāo)注在辦法上,通過反射解析出辦法所在的類,遍歷這個類里的所有辦法,找到注解所對應(yīng)的那個辦法,調(diào)用invoke,執(zhí)行辦法的過程中,用threadLocal存儲的數(shù)據(jù)源名字進(jìn)行動態(tài)切換.下面進(jìn)行詳細(xì)講解：

1. 自定義一個注解,作用是標(biāo)注辦法

1. package com.tiangou.annotation;

2. import java.lang.annotation.Documented;

3. import java.lang.annotation.ElementType;

4. import java.lang.annotation.Retention;

5. import java.lang.annotation.RetentionPolicy;

6. import java.lang.annotation.Target;

7. @Documented

8. @Retention(RetentionPolicy.RUNTIME)

9. @Target(ElementType.METHOD)

10. public @interface DataSource {

11. String name() default "";

12. }

2.ThreadLocal保留數(shù)據(jù)庫

1. package com.tiangou.dataSource;

2. public class DataSourceContextHolder {

1. private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();

2. public static void setDbType(String dbType) {

3.AbstractRoutingDataSource spring動態(tài)切換數(shù)據(jù)源

1. contextHolder.set(dbType);

2. }

3. public static String getDbType() {

4. return ((String) contextHolder.get());

5. }

6. public static void clearDbType() {

7. contextHolder.remove();

8. }

9. }

10. package com.tiangou.dataSource;

11. import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

12. public class DynamicDataSource extends AbstractRoutingDataSource{

13. @Override

14. protected Object determineCurrentLookupKey() {

15. System.out.println(DataSourceContextHolder.getDbType());

16. return DataSourceContextHolder.getDbType();

17. }

18. }

4.配置文件中配置aop切面

<?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:p="http://www.springframework.org/schema/p"

xmlns:aop="http://www.springframework.org/schema/aop"

xmlns:context="http://www.springframework.org/schema/context"

xmlns:jee="http://www.springframework.org/schema/jee"

xmlns:tx="http://www.springframework.org/schema/tx"

xsi:schemaLocation="

http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd

http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd

http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd

http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.0.xsd

http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

<!-- 配置數(shù)據(jù)源 -->

<import resource="classpath*:mongodb.xml" />

<import resource="classpath*:redis.xml" />

<!-- <import resource="classpath*:rabbitMq.xml" /> -->

<aop:aspectj-autoproxy proxy-target-class="true"/>

<!-- 使用注解的包,包含子集 -->

<bean id="db1"

class="com.alibaba.druid.pool.DruidDataSource">

<property name="url" value="jdbc:mysql://localhost:3306/tiangou?useUnicode=true&amp;characterEncoding=UTF-8"/>

<property name="username" value="root"/>

<property name="password" value="root"/>

</bean>

<bean id="db2"

class="com.alibaba.druid.pool.DruidDataSource">

<property name="url" value="jdbc:mysql://localhost:3306/tiangou2?useUnicode=true&amp;characterEncoding=UTF-8"/>

<property name="username" value="root"/>

<property name="password" value="root"/>

</bean>

<bean id="dataSource" class="com.tiangou.dataSource.DynamicDataSource">

<property name="targetDataSources">

<map key-type="java.lang.String">

<entry key="db1" value-ref="db1" />

<entry key="db2" value-ref="db2" />

</map>

</property>

<property name="defaultTargetDataSource" ref="db1" />

</bean>

<!-- 配置mybatis的sqlSessionFactory -->

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

<property name="dataSource" ref="dataSource" />

<!-- 自動掃描mappers.xml文件 -->

<property name="mapperLocations" value="classpath:com/tiangou/mapper/*.xml"></property>

<!-- mybatis配置文件 -->

<property name="configLocation" value="classpath:mybatis-config.xml"></property>

</bean>

<!-- DAO接口所在包名,Spring會自動查找其下的類 -->

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">

<property name="basePackage" value="com.tiangou.mapper" />

<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>

</bean>

<!-- 開啟事務(wù)注解驅(qū)動 -->

<tx:annotation-driven proxy-target-class="true" order="2" />

<!-- (事務(wù)管理)transaction manager, use JtaTransactionManager for global tx -->

<bean id="transactionManager"

class="org.springframework.jdbc.datasource.DataSourceTransactionManager">

<property name="dataSource" ref="dataSource" />

</bean>

<!-- 配置事務(wù)通知屬性 -->

<tx:advice id="txAdvice" transaction-manager="transactionManager">

<!-- 定義事務(wù)傳播屬性 -->

<tx:attributes>

<tx:method name="insert*" propagation="REQUIRED" />

<tx:method name="update*" propagation="REQUIRED" />

<tx:method name="edit*" propagation="REQUIRED" />

<tx:method name="save*" propagation="REQUIRED" />

<tx:method name="add*" propagation="REQUIRED" />

<tx:method name="new*" propagation="REQUIRED" />

<tx:method name="set*" propagation="REQUIRED" />

<tx:method name="remove*" propagation="REQUIRED" />

<tx:method name="delete*" propagation="REQUIRED" />

<tx:method name="change*" propagation="REQUIRED" />

<tx:method name="check*" propagation="REQUIRED" />

<tx:method name="get*" propagation="REQUIRED"/>

<tx:method name="find*" propagation="REQUIRED" />

<tx:method name="load*" propagation="REQUIRED"/>

<tx:method name="*" propagation="REQUIRED" />

</tx:attributes>

</tx:advice>

<!-- SpringMVC在超出上傳文件限制時,會拋出

org.springframework.web.multipart.MaxUploadSizeExceededException -->

<!-- 該異常是SpringMVC在檢查上傳的文件信息時拋出來的,而且此時還沒有進(jìn)入到Controller辦法中 -->

<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">

<property name="exceptionMappings">

<props>

<!-- 遇到

MaxUploadSizeExceededException異常時,自動跳轉(zhuǎn)到

/WEB-INF/error_fileupload.jsp頁面 -->

<prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">WEB-INF/error_fileupload</prop>

<!-- 處理其它異常(包含Controller拋出的) -->

<prop key="java.lang.Throwable">WEB-INF/500</prop>

</props>

</property>

</bean>

<!-- 配置事務(wù)切面 -->

<aop:config>

<aop:pointcut id="serviceOperation"

expression="execution(* com.tiangou.service.*.*(..))" />

<aop:advisor advice-ref="txAdvice" pointcut-ref="serviceOperation" />

</aop:config>

<!--

shiroQUANXIAN

-->

<!-- 繼承自AuthorizingRealm的自定義Realm,即指定Shiro驗證用戶登錄的類為自定義的ShiroDbRealm.java -->

<!-- <bean id="myRealm" class="com.tiangou.realm.MyRealm"/> -->

<!-- Shiro默認(rèn)會使用Servlet容器的Session,可通過sessionMode屬性來指定使用Shiro原生Session -->

<!-- 即<property name="sessionMode" value="native"/>,詳細(xì)說明見官方文檔 -->

<!-- 這里主要是設(shè)置自定義的單Realm應(yīng)用,若有多個Realm,可使用'realms'屬性代替 -->

<!-- <bean id="securityManager" class="org.apache.shiro.web.mgt.DefaultWebSecurityManager"> -->

<!-- <property name="realm" ref="myRealm"/> -->

<!-- </bean> -->

<!-- Shiro主過濾器自己功能十分強(qiáng)大,其強(qiáng)大之處就在于它支持任何基于URL路徑表達(dá)式的、自定義的過濾器的執(zhí)行 -->

<!-- Web應(yīng)用中,Shiro可控制的Web哀求必須經(jīng)過Shiro主過濾器的攔截,Shiro對基于Spring的Web應(yīng)用提供了完美的支持 -->

<!-- <bean id="shiroFilter" class="org.apache.shiro.spring.web.ShiroFilterFactoryBean"> -->

<!-- Shiro的核心平安接口,這個屬性是必須的 -->

<!-- <property name="securityManager" ref="securityManager"/> -->

<!-- 要求登錄時的鏈接(可根據(jù)項目的URL進(jìn)行替換),非必需的屬性,默認(rèn)會自動尋找Web工程根目錄下的"/login.jsp"頁面 -->

<!-- <property name="loginUrl" value="/"/> -->

<!-- 登錄成功后要跳轉(zhuǎn)的連接(本例中此屬性用不到,因為登錄成功后的處理邏輯在LoginController里硬編碼為main.jsp了) -->

<!-- <property name="successUrl" value="/system/main"/> -->

<!-- 用戶拜訪未對其授權(quán)的資源時,所顯示的連接 -->

<!-- 若想更明顯的測試此屬性可以修改它的值,如unauthor.jsp,然后用[玄玉]登錄后拜訪/admin/listUser.jsp就看見瀏覽器會顯示unauthor.jsp -->

<!-- <property name="unauthorizedUrl" value="/"/> -->

<!-- Shiro連接約束配置,即過濾鏈的定義 -->

<!-- 此處可配合我的這篇文章來理解各個過濾連的作用

http://blog.csdn.net/jadyer/article/details/12172839 -->

<!-- 下面value值的第一個'/'代表的路徑是相對于

HttpServletRequest.getContextPath()的值來的 -->

<!-- anon：它對應(yīng)的過濾器里面是空的,什么都沒做,這里.do和.jsp后面的*表示參數(shù),比喻說login.jsp?main這種 -->

<!-- authc：該過濾器下的頁面必須驗證后才能拜訪,它是Shiro內(nèi)置的一個攔截器

org.apache.shiro.web.filter.authc.FormAuthenticationFilter -->

<!-- <property name="filterChainDefinitions"> -->

<!-- <value> -->

<!-- /mydemo/login=anon -->

<!-- /mydemo/getVerifyCodeImage=anon -->

<!-- /main**=authc -->

<!-- /user/info**=authc -->

<!-- /admin/listUser**=authc,perms[admin:manage] -->

<!-- </value> -->

<!-- </property> -->

<!-- </bean> -->

<!-- 保證實現(xiàn)了Shiro內(nèi)部lifecycle函數(shù)的bean執(zhí)行 -->

<!-- <bean id="lifecycleBeanPostProcessor" class="org.apache.shiro.spring.LifecycleBeanPostProcessor"/> -->

<!-- 開啟Shiro的注解(如@RequiresRoles,@RequiresPermissions),需借助SpringAOP掃描使用Shiro注解的類,并在必要時進(jìn)行平安邏輯驗證 -->

<!-- 配置以下兩個bean即可實現(xiàn)此功能 -->

<!-- Enable Shiro Annotations for Spring-configured beans. Only run after the lifecycleBeanProcessor has run -->

<!-- 由于本例中并未使用Shiro注解,故注釋掉這兩個bean(個人覺得將權(quán)限通過注解的方式硬編碼在程序中,查看起來不是很方便,沒需要使用) -->

<!--

<bean class="org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator" depends-on="lifecycleBeanPostProcessor"/>

<bean class="org.apache.shiro.spring.security.interceptor.AuthorizationAttributeSourceAdvisor">

<property name="securityManager" ref="securityManager"/>

</bean> -->

<!-- 自動掃描 -->

<context:component-scan base-package="com.tiangou.service,com.tiangou.aop" />

<context:component-scan base-package="com.tiangou.websocket" />

</beans>

5.對調(diào)用的辦法上進(jìn)行辨別,切換數(shù)據(jù)源

以上就是動態(tài)切換數(shù)據(jù)源的講解,必要源碼的私信我,喜歡小編的給我一波關(guān)注,謝謝.