├── DataSourceAdvice
├── DataSourceSwitcher
├── DynamicDataSource.java
├── README.md
└── application-data-source.xml


/DataSourceAdvice:
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 1 | import java.lang.reflect.Method;
 2 | import java.text.MessageFormat;
 3 | import java.util.List;
 4 | 
 5 | import org.apache.log4j.Logger;
 6 | import org.springframework.aop.AfterReturningAdvice;
 7 | import org.springframework.aop.MethodBeforeAdvice;
 8 | 
 9 | /**
10 |  * @author aelns
11 |  *
12 |  */
13 | public class DataSourceAdvice implements MethodBeforeAdvice, AfterReturningAdvice {
14 | 	
15 | 	private DataSourceSwitcher switcher;
16 | 	
17 | 	private Logger logger = Logger.getLogger(DataSourceAdvice.class);
18 | 	
19 | 	private List<String> readMethodNames;
20 | 	
21 | 	public List<String> getReadMethodNames() {
22 | 		return readMethodNames;
23 | 	}
24 | 
25 | 	public void setReadMethodNames(List<String> readMethodNames) {
26 | 		this.readMethodNames = readMethodNames;
27 | 	}
28 | 	
29 | 	/**
30 | 	 * before calling the service method, automatically switching data source
31 | 	 */
32 | 	public void before(Method method, Object[] args, Object target)
33 | 			throws Throwable {
34 | 		if (isReadMethod(method.getName())) {
35 | 			switcher.setSlave();
36 | 		} else {
37 | 			switcher.setMaster();
38 | 		}
39 | 		if (logger.isDebugEnabled()) {
40 | 			logger.debug(MessageFormat.format(
41 | 					"Point cut: {0}-{1} switch data source to {2}",
42 | 					target.getClass().getName(), method.getName(), switcher.getDataSource()));
43 | 		}
44 | 	}
45 | 	
46 | 	/**
47 | 	 * @param methodName
48 | 	 * @return
49 | 	 */
50 | 	private boolean isReadMethod(String methodName) {
51 | 		for (String name : readMethodNames) {
52 | 			if (methodName.startsWith(name)) {
53 | 				return true;
54 | 			}
55 | 		}
56 | 		return false;
57 | 	}
58 | 
59 | 	public void afterReturning(Object arg0, Method method, Object[] args,
60 | 			Object target) throws Throwable {
61 | 	}
62 | 
63 | 	/**
64 | 	 * @param method
65 | 	 * @param args
66 | 	 * @param target
67 | 	 * @param e
68 | 	 * @throws Throwable
69 | 	 */
70 | 	public void afterThrowing(Method method, Object[] args, Object target,
71 | 			Exception e) throws Throwable {
72 | 		if (e instanceof java.sql.SQLException) {
73 | 			logger.error("Occur error, will switch to master datasource");
74 | 			logger.error(e, e);
75 | 			switcher.setMaster();
76 | 		}
77 | 	}
78 | 
79 | 	public DataSourceSwitcher getSwitcher() {
80 | 		return switcher;
81 | 	}
82 | 
83 | 	public void setSwitcher(DataSourceSwitcher switcher) {
84 | 		this.switcher = switcher;
85 | 	}
86 | }
87 | 


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/DataSourceSwitcher:
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 1 | import java.util.List;
 2 | import java.util.concurrent.atomic.AtomicInteger;
 3 | 
 4 | /**
 5 |  * 
 6 |  * @author aelns
 7 |  *
 8 |  */
 9 | public class DataSourceSwitcher {
10 | 	
11 | 	private ThreadLocal<String> contextHolder = new ThreadLocal<String>();
12 | 	
13 | 	private AtomicInteger index = new AtomicInteger(0);
14 | 	
15 | 	private List<String> slaves;
16 | 
17 | 	public void setDataSource(String dataSource) {
18 | 		contextHolder.set(dataSource);
19 | 	}
20 | 
21 | 	public void setMaster() {
22 | 		clearDataSource();
23 | 		setDataSource("master");
24 | 	}
25 | 
26 | 	public void setSlave() {
27 | 		clearDataSource();
28 | 		if (index.get() >= slaves.size()) {
29 | 			index.set(0);
30 | 		}
31 | 		setDataSource(slaves.get(index.get() % slaves.size()));
32 | 		index.addAndGet(1);
33 | 	}
34 | 
35 | 	public String getDataSource() {
36 | 		return (String) contextHolder.get();
37 | 	}
38 | 
39 | 	public void clearDataSource() {
40 | 		contextHolder.remove();
41 | 	}
42 | 
43 | 	public List<String> getSlaves() {
44 | 		return slaves;
45 | 	}
46 | 
47 | 	public void setSlaves(List<String> slaves) {
48 | 		this.slaves = slaves;
49 | 	}
50 | }
51 | 


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/DynamicDataSource.java:
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 1 | import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;  
 2 | 
 3 | /**
 4 |  * 
 5 |  * @author aelns
 6 |  *
 7 |  */
 8 | public class DynamicDataSource extends AbstractRoutingDataSource {
 9 | 	
10 | 	private DataSourceSwitcher switcher;
11 | 	
12 |     @Override  
13 |     protected Object determineCurrentLookupKey() {  
14 |         return switcher.getDataSource();  
15 |     }
16 | 
17 | 	public DataSourceSwitcher getSwitcher() {
18 | 		return switcher;
19 | 	}
20 | 
21 | 	public void setSwitcher(DataSourceSwitcher switcher) {
22 | 		this.switcher = switcher;
23 | 	}
24 | } 
25 | 


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/README.md:
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1 | # separate-read-and-write
2 | 基于Spring AOP的数据库读写分离实现, 这里演示使用的是Mybatis + MySQL + Spring AOP
3 | 
4 | 对于多个数据源简单的实现为逐个轮询,如果有需要可以自己可以实现其他的算法
5 | 


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/application-data-source.xml:
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  1 | <?xml version="1.0" encoding="UTF-8"?>
  2 | <beans xmlns="http://www.springframework.org/schema/beans"
  3 | 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
  4 | 	xmlns:lang="http://www.springframework.org/schema/lang" xmlns:tx="http://www.springframework.org/schema/tx"
  5 | 	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
  6 | 	xmlns:cache="http://www.springframework.org/schema/cache" xmlns:mvc="http://www.springframework.org/schema/mvc"
  7 | 	xmlns:task="http://www.springframework.org/schema/task"
  8 | 	xsi:schemaLocation="http://www.springframework.org/schema/beans
  9 | 	         http://www.springframework.org/schema/beans/spring-beans.xsd
 10 | 	         http://www.springframework.org/schema/lang
 11 | 	         http://www.springframework.org/schema/lang/spring-lang.xsd      
 12 | 	         http://www.springframework.org/schema/tx   
 13 | 	         http://www.springframework.org/schema/tx/spring-tx.xsd    
 14 | 	         http://www.springframework.org/schema/aop     
 15 | 	         http://www.springframework.org/schema/aop/spring-aop.xsd    
 16 | 	         http://www.springframework.org/schema/mvc     
 17 | 	         http://www.springframework.org/schema/mvc/spring-mvc.xsd   
 18 | 	         http://www.springframework.org/schema/context     
 19 | 	         http://www.springframework.org/schema/context/spring-context.xsd
 20 | 	         http://www.springframework.org/schema/cache
 21 | 	         http://www.springframework.org/schema/cache/spring-cache.xsd
 22 | 	         http://www.springframework.org/schema/task 
 23 | 	         http://www.springframework.org/schema/task/spring-task.xsd" default-lazy-init="true">
 24 | 	         
 25 | 	<!-- 创建SqlSessionFactory，同时指定数据源 -->
 26 | 	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
 27 | 		<property name="dataSource" ref="dataSource" />
 28 | 		<property name="configLocation" value="classpath:mybatis-config.xml" />
 29 | 		<property name="typeAliasesPackage" value="com.test.model" />
 30 | 		<property name="mapperLocations">
 31 | 			<list>
 32 | 				<value>classpath*:/com/test/dao/mapper/*.xml</value>
 33 | 				<value>classpath*:/com/test/dao/customize/*.xml</value>
 34 | 			</list>
 35 | 		</property>
 36 | 		<property name="typeHandlersPackage" value="com.github.javaplugs.mybatis" />
 37 | 	</bean>
 38 | 
 39 | 	<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate"
 40 | 		scope="prototype">
 41 | 		<constructor-arg index="0" ref="sqlSessionFactory" />
 42 | 	</bean>
 43 | 
 44 | 	<!--创建数据映射器，数据映射器必须为接口 -->
 45 | 	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
 46 | 		<!-- <property name="annotationClass" value="org.springframework.stereotype.Repository" 
 47 | 			/> -->
 48 | 		<property name="basePackage" value="com.test.dao" />
 49 | 	</bean>
 50 | 	
 51 | 	<bean id="switcher" class="com.test.core.database.DataSourceSwitcher" >
 52 | 		<property name="slaves">
 53 | 			<list>
 54 | 				<value>slave1</value>
 55 | <!-- 				<value>slave2</value> -->
 56 | <!-- 				<value>slave3</value> -->
 57 | 			</list>
 58 | 		</property>
 59 | 	</bean>
 60 | 	
 61 | 	<bean id="dataSource" class="com.test.core.database.DynamicDataSource">
 62 | 		<property name="switcher" ref="switcher"></property>
 63 | 		<property name="targetDataSources">
 64 | 			<map key-type="java.lang.String">
 65 | 				<entry key="master" value-ref="masterDataSource" />
 66 | 				<entry key="slave1" value-ref="slave1DataSource" />
 67 | <!-- 				<entry key="slave2" value-ref="slave2DataSource" /> -->
 68 | <!-- 				<entry key="slave3" value-ref="slave3DataSource" /> -->
 69 | 			</map>
 70 | 		</property>
 71 | 		<property name="defaultTargetDataSource" ref="masterDataSource" />
 72 | 	</bean>
 73 | 
 74 | 	<!-- master data source -->
 75 | 	<bean id="masterDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
 76 | 		<property name="driverClassName" value="${jdbc.driverClass}" />
 77 | 		<property name="url" value="${master.jdbc.url}" />
 78 | 		<property name="username" value="${master.jdbc.userName}" />
 79 | 		<property name="password" value="${master.jdbc.password}"/>
 80 | 		<property name="defaultAutoCommit" value="true"></property>
 81 | 		<property name="maxActive" value="${jdbc.maxActive}" />  
 82 |         <property name="initialSize" value="${jdbc.initialSize}" />  
 83 |         <property name="maxWait" value="${jdbc.maxWait}" />  
 84 |         <property name="maxIdle" value="${jdbc.maxIdle}" />  
 85 |         <property name="minIdle" value="${jdbc.minIdle}" />  
 86 |         <property name="removeAbandoned" value="true" />  
 87 |         <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}" />  
 88 |         <property name="connectionProperties">  
 89 |             <value>clientEncoding=utf-8</value>  
 90 |         </property>
 91 |          <!-- 打开检查,用异步线程evict进行检查 -->
 92 |         <property name="testWhileIdle"><value>true</value></property>  
 93 | 	    <property name="testOnBorrow"><value>false</value></property>  
 94 | 	    <property name="testOnReturn"><value>false</value></property>  
 95 | 	    <property name="validationQuery"><value>SELECT NOW() FROM dual</value></property>  
 96 | 	    <property name="validationQueryTimeout"><value>1</value></property>  
 97 | 	    <property name="timeBetweenEvictionRunsMillis"><value>30000</value></property>  
 98 | 	    <property name="numTestsPerEvictionRun"><value>20</value></property>  
 99 | 	</bean>
100 | 	
101 | 	<!-- slave data source -->
102 | 	<bean id="slave1DataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
103 | 		<property name="driverClassName" value="${jdbc.driverClass}" />
104 | 		<property name="url" value="${slave.jdbc.url}" />
105 | 		<property name="username" value="${slave.jdbc.userName}" />
106 | 		<property name="password" value="${slave.jdbc.password}" />
107 | 		<property name="defaultAutoCommit" value="true"></property>
108 | 		<property name="maxActive" value="${jdbc.maxActive}" />  
109 |         <property name="initialSize" value="${jdbc.initialSize}" />  
110 |         <property name="maxWait" value="${jdbc.maxWait}" />  
111 |         <property name="maxIdle" value="${jdbc.maxIdle}" />  
112 |         <property name="minIdle" value="${jdbc.minIdle}" />  
113 |         <property name="removeAbandoned" value="true" />  
114 |         <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}" />  
115 |         <property name="connectionProperties">  
116 |             <value>clientEncoding=utf-8</value>  
117 |         </property>
118 |          <!-- 打开检查,用异步线程evict进行检查 -->
119 |         <property name="testWhileIdle"><value>true</value></property>  
120 | 	    <property name="testOnBorrow"><value>false</value></property>  
121 | 	    <property name="testOnReturn"><value>false</value></property>  
122 | 	    <property name="validationQuery"><value>SELECT NOW() FROM dual</value></property>  
123 | 	    <property name="validationQueryTimeout"><value>1</value></property>  
124 | 	    <property name="timeBetweenEvictionRunsMillis"><value>30000</value></property>  
125 | 	    <property name="numTestsPerEvictionRun"><value>20</value></property>
126 | 	</bean>
127 | 	
128 | <!-- 	<bean id="slave2DataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> -->
129 | <!-- 		<property name="driverClassName" value="${jdbc.driverClass}" /> -->
130 | <!-- 		<property name="url" value="${slave.jdbc.url}" /> -->
131 | <!-- 		<property name="username" value="${slave.jdbc.userName}" /> -->
132 | <!-- 		<property name="password" value="${slave.jdbc.password}" /> -->
133 | <!-- 		<property name="defaultAutoCommit" value="true"></property> -->
134 | <!-- 		<property name="maxActive" value="${jdbc.maxActive}" />   -->
135 | <!--         <property name="initialSize" value="${jdbc.initialSize}" />   -->
136 | <!--         <property name="maxWait" value="${jdbc.maxWait}" />   -->
137 | <!--         <property name="maxIdle" value="${jdbc.maxIdle}" />   -->
138 | <!--         <property name="minIdle" value="${jdbc.minIdle}" />   -->
139 | <!--         <property name="removeAbandoned" value="true" />   -->
140 | <!--         <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}" />   -->
141 | <!--         <property name="connectionProperties"> -->
142 | <!--             <value>clientEncoding=utf-8</value>  -->
143 | <!--         </property>   -->
144 | <!-- 	</bean> -->
145 | 	
146 | <!-- 	<bean id="slave3DataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> -->
147 | <!-- 		<property name="driverClassName" value="${jdbc.driverClass}" /> -->
148 | <!-- 		<property name="url" value="${slave.jdbc.url}" /> -->
149 | <!-- 		<property name="username" value="${slave.jdbc.userName}" /> -->
150 | <!-- 		<property name="password" value="${slave.jdbc.password}" /> -->
151 | <!-- 		<property name="defaultAutoCommit" value="true"></property> -->
152 | <!-- 		<property name="maxActive" value="${jdbc.maxActive}" />   -->
153 | <!--         <property name="initialSize" value="${jdbc.initialSize}" />   -->
154 | <!--         <property name="maxWait" value="${jdbc.maxWait}" />   -->
155 | <!--         <property name="maxIdle" value="${jdbc.maxIdle}" />   -->
156 | <!--         <property name="minIdle" value="${jdbc.minIdle}" />   -->
157 | <!--         <property name="removeAbandoned" value="true" />   -->
158 | <!--         <property name="removeAbandonedTimeout" value="${jdbc.removeAbandonedTimeout}" />   -->
159 | <!--         <property name="connectionProperties">   -->
160 | <!--             <value>clientEncoding=utf-8</value>   -->
161 | <!--         </property>   -->
162 | <!-- 	</bean> -->
163 | 
164 | 	<!-- 根据方法名切换数据源 -->  
165 |     <bean id="dataSourceAdvice" class="com.test.core.database.DataSourceAdvice" >
166 |     	<property name="switcher" ref="switcher"></property>
167 |     	<property name="readMethodNames">
168 |     		<list>
169 | 				<value>query</value>
170 | 				<value>use</value>
171 | 				<value>get</value>
172 | 				<value>count</value>
173 | 				<value>find</value>
174 | 				<value>list</value>
175 | 				<value>load</value>
176 | 				<value>search</value>
177 | 				<value>populate</value>
178 | 				<value>login</value>
179 | 			</list>
180 |     	</property>
181 |     </bean>
182 |     
183 |     <aop:config>  
184 |         <aop:advisor
185 |             pointcut="execution(* com.test..*Service*.*(..))" order="1"  
186 |             advice-ref="dataSourceAdvice" />
187 |     </aop:config>  
188 | </beans>
189 | 


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