springMVC+mybatis多資料來源配置（dao掃描版本）
阿新 • • 發佈：2019-02-09
<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">原理圖如下</span>
我們通過改變dao的session就可以達到資料庫的切換，讀寫分離，多資料來源就方便起來。
以下是主要配置程式碼
applicationContext.xml
<?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-3.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"> <context:annotation-config /> <context:component-scan base-package="com.test.service" /> <context:property-placeholder location="classpath*:application.properties" /> <import resource="classpath:spring/applicationContext-persistence.xml" /> <import resource="classpath:spring/applicationContext-tx.xml" /> <bean id="dataSourceInterceptor" class="com.test.db.DataSourceInterceptor"></bean> <aop:config> <aop:aspect id="dataSourceAspect" ref="dataSourceInterceptor"> <aop:pointcut id="daoOne" expression="execution(* com.test.dao.test1.*.*(..))" /> <aop:pointcut id="daoTwo" expression="execution(* com.test.dao.test2.*.*(..))" /> <aop:before pointcut-ref="daoOne" method="setdataSourceOne" /> <aop:before pointcut-ref="daoTwo" method="setdataSourceTwo" /> </aop:aspect> </aop:config> </beans>
applicationContext-persistence.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd "> <bean id="dataSourceOne" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${jdbc.driver}" /> <property name="jdbcUrl" value="${jdbc.url}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <property name="initialPoolSize" value="${c3p0.initialpoolsize}" /> <property name="minPoolSize" value="${c3p0.minpoolsize}" /> <property name="maxPoolSize" value="${c3p0.maxpoolsize}" /> <property name="maxIdleTime" value="${c3p0.maxidletime}" /> <property name="preferredTestQuery" value="select 1" /> <property name="breakAfterAcquireFailure" value="true" /> <property name="connectionTesterClassName" value="com.mchange.v2.c3p0.impl.DefaultConnectionTester" /> <property name="acquireIncrement" value="5" /> <property name="maxIdleTimeExcessConnections" value="600" /> <!-- 開啟重連機制並設定重連次數為10 --> <property name="idleConnectionTestPeriod" value="60" /> <property name="acquireRetryAttempts" value="10" /> <property name="acquireRetryDelay" value="30000" /> <property name="testConnectionOnCheckin" value="true" /> <property name="testConnectionOnCheckout" value="false" /> <property name="checkoutTimeout" value="5000" /> </bean> <bean id="dataSourceTwo" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${jdbc.driver}" /> <property name="jdbcUrl" value="${jdbc.url2}"/> <property name="user" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> <property name="initialPoolSize" value="${c3p0.initialpoolsize}" /> <property name="minPoolSize" value="${c3p0.minpoolsize}" /> <property name="maxPoolSize" value="${c3p0.maxpoolsize}" /> <property name="maxIdleTime" value="${c3p0.maxidletime}" /> <property name="preferredTestQuery" value="select 1" /> <property name="breakAfterAcquireFailure" value="true" /> <property name="connectionTesterClassName" value="com.mchange.v2.c3p0.impl.DefaultConnectionTester" /> <property name="acquireIncrement" value="5" /> <property name="maxIdleTimeExcessConnections" value="600" /> <!-- 開啟重連機制並設定重連次數為10 --> <property name="idleConnectionTestPeriod" value="60" /> <property name="acquireRetryAttempts" value="10" /> <property name="acquireRetryDelay" value="30000" /> <property name="testConnectionOnCheckin" value="true" /> <property name="testConnectionOnCheckout" value="false" /> <property name="checkoutTimeout" value="5000" /> </bean> <bean id="dynamicDataSource" class="com.test.db.DynamicDataSource"> <property name="targetDataSources"> <map key-type="java.lang.String"> <entry value-ref="dataSourceOne" key="dataSourceOne"></entry> <entry value-ref="dataSourceTwo" key="dataSourceTwo"></entry> </map> </property> <property name="defaultTargetDataSource" ref="dataSourceOne"> </property> </bean> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dynamicDataSource" /> <property name="configLocation" value="classpath:mybatis-setting.xml"></property> <!-- Mybatis SQL配置檔案路徑 --> <property name="mapperLocations"> <list> <!-- 載入當前工程和commons工程中的對映檔案 --> <value>classpath*:/mybatis/**/*-Mapper.xml</value> </list> </property> </bean> <!-- 掃描Dao介面 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <!-- 掃描當前工程和commons工程中的DAO介面 --> <property name="basePackage" value="com.test.dao" /> </bean> </beans>
applicationContext-tx.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd "> <!-- MyBatis依賴於jdbc事務管理 --> <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSourceOne" /> </bean> <!-- 事務攔截器配置 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="get*" read-only="true" /> <tx:method name="find*" read-only="true" /> <tx:method name="*" propagation="REQUIRED" rollback-for="Exception" /> </tx:attributes> </tx:advice> <aop:config> <!--將事務切入到Service層中--> <aop:pointcut id="txAdvicePointcut" expression="execution(* com.joygame.socialservice.service.*.*(..))" /> <aop:advisor pointcut-ref="txAdvicePointcut" advice-ref="txAdvice" /> </aop:config> </beans>
db核心程式碼
DatabaseContextHolder.java
package com.test.db;
public class DatabaseContextHolder {
private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
public static void setCustomerType(String customerType) {
contextHolder.set(customerType);
}
public static String getCustomerType() {
return contextHolder.get();
}
public static void clearCustomerType() {
contextHolder.remove();
}
}package com.test.db;
import org.aspectj.lang.JoinPoint;
import org.springframework.stereotype.Component;
@Component
public class DataSourceInterceptor {
public void setdataSourceOne(JoinPoint jp) {
DatabaseContextHolder.setCustomerType("dataSourceOne");
}
public void setdataSourceTwo(JoinPoint jp) {
DatabaseContextHolder.setCustomerType("dataSourceTwo");
}
}package com.test.db;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource{
@Override
protected Object determineCurrentLookupKey() {
return DatabaseContextHolder.getCustomerType();
}
}
測試程式碼
package com.test.action;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.test.service.TestService;
@Controller
public class TestAction {
@Autowired
private TestService testService;
@RequestMapping(value="/test.do",method={RequestMethod.GET,RequestMethod.POST})
public void index(){
testService.insert();
}
}
package com.test.service;
public interface TestService {
void insert();
}
package com.test.service.impl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.test.dao.test1.TestDao;
import com.test.dao.test2.TestDao2;
import com.test.model.Test;
import com.test.service.TestService;
@Service
public class TestServiceImpl implements TestService {
@Autowired
private TestDao testDao;
@Autowired
private TestDao2 testDao2;
public void insert() {
// Test t = new Test();
// t.setName("hury");
// testDao.insert(t);
// testDao2.insert(t);
System.out.println(testDao.count());
System.out.println(testDao2.count());
}
public TestDao getTestDao() {
return testDao;
}
public TestDao2 getTestDao2() {
return testDao2;
}
public void setTestDao(TestDao testDao) {
this.testDao = testDao;
}
public void setTestDao2(TestDao2 testDao2) {
this.testDao2 = testDao2;
}
}
package com.test.model;
public final class Test {
private int id;
private String name;
public int getId() {
return id;
}
public String getName() {
return name;
}
public void setId(int id) {
this.id = id;
}
public void setName(String name) {
this.name = name;
}
}
package com.test.dao.test1;
import com.test.model.Test;
public interface TestDao {
int insert(Test t);
int count();
}
package com.test.dao.test2;
import com.test.model.Test;
public interface TestDao2 {
int insert(Test t);
int count();
}
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.test.dao.test1.TestDao">
<insert id="insert">
insert into test(name)
values (#{name})
</insert>
<select id="count" resultType="int">
select count(0) from test
</select>
</mapper><?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.test.dao.test2.TestDao2">
<insert id="insert">
insert into test2(name1)
values (#{name})
</insert>
<select id="count" resultType="int">
select count(0) from test2
</select>
</mapper>2
[INFO][com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource] - <Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 5, acquireRetryAttempts -> 10, acquireRetryDelay -> 30000, autoCommitOnClose -> false, automaticTestTable
-> null, breakAfterAcquireFailure -> true, checkoutTimeout -> 5000, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 1b6171r921ffm2ghcf7zd1|5866ff, debugUnreturnedConnectionStackTraces
-> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1b6171r921ffm2ghcf7zd1|5866ff, idleConnectionTestPeriod -> 60, initialPoolSize -> 1, jdbcUrl ->
jdbc:mysql://localhost:3306/test2?createDatabaseIfNotExist=true&useUnicode=true&characterEncoding=UTF-8, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 3600, maxIdleTimeExcessConnections -> 600, maxPoolSize -> 50, maxStatements -> 0,
maxStatementsPerConnection -> 0, minPoolSize -> 5, numHelperThreads -> 3, preferredTestQuery -> select 1, properties -> {user=******, password=******}, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, testConnectionOnCheckin -> true, testConnectionOnCheckout
-> false, unreturnedConnectionTimeout -> 0, userOverrides -> {}, usesTraditionalReflectiveProxies -> false ]>
6
如果若要事用務，請將AOP 配置service層, DataSourceTransactionManager 注入的dataSource 就為AbstractRoutingDataSource 獲取connection.
public Connection getConnection() throws SQLException {
return determineTargetDataSource().getConnection();
}
---------
protected DataSource determineTargetDataSource() {
Assert.notNull(this.resolvedDataSources, "DataSource router not initialized");
Object lookupKey = determineCurrentLookupKey();
DataSource dataSource = this.resolvedDataSources.get(lookupKey);
if (dataSource == null && (this.lenientFallback || lookupKey == null)) {
dataSource = this.resolvedDefaultDataSource;
}
if (dataSource == null) {
throw new IllegalStateException("Cannot determine target DataSource for lookup key [" + lookupKey + "]");
}
return dataSource;
}
-----------------------------------------
因此可知道，這樣事務就可以管理多資料來源中獲取到的connection, session ＝ connection.getSession(0事務了。
對資料來源重點就是通過route演算法，獲取connection過程