本文主要是介绍Spring实现数据库读写分离/spring事务配置解释(Annotation/Spring AOP/Reflection)，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
项目开发中读写的频率差距很大，所以实现读写分离：主库(master)中非实时读取的查询交给负载均衡的从库(slave)，查询cpu的消耗和写入的io延时，保证DB系统的健壮性。
最终问题，分布式事务的线索。最后附源码[springmvc+spring+mybatis+MySQL]：
注：注释和部分代码省略。
1：AbstractRoutingDataSource这个数据源路由类是spring2.0以后增加的，AbstractRoutingDataSource的定义：/* @since 2.0.1*/
public abstract class AbstractRoutingDataSource extends AbstractDataSource implements InitializingBean {……}
通过实现determineCurrentLookupKey()抽象方法可以实现读写数据源的切换。
2：AbstractRoutingDataSource继承了AbstractDataSource，而AbstractDataSource是DataSource的子类。DataSource是javax.sql的数据源接口，定义：
public interface DataSource extends CommonDataSource,Wrapper {Connection getConnection() throws SQLException;Connection getConnection(String username, String password) throws SQLException;
}
DataSource数据源接口定义了2个方法，都是获取数据库连接的。
3：AbstractRoutingDataSource这个数据源路由类对获取连接的实现：
public abstract class AbstractRoutingDataSource extends AbstractDataSource implements InitializingBean {private Map<Object, DataSource> resolvedDataSources;private Object defaultTargetDataSource;private Map<Object, Object> targetDataSources;@Overridepublic Connection getConnection() throws SQLException {return determineTargetDataSource().getConnection();}@Overridepublic Connection getConnection(String username, String password) throws SQLException {return determineTargetDataSource().getConnection(username, password);}protected abstract Object determineCurrentLookupKey();
}
通过自己定义的determineTargetDataSource()方法获取到数据连接connection。
4：determineTargetDataSource的定义：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;}
determineCurrentLookupKey方法返回lookupKey,resolvedDataSources方法就是根据lookupKey从Map中获得数据源。从3看出resolvedDataSources集合属性和determineCurrentLookupKey()抽象方法定义。
5：我们自己定义类继承路由类AbstractRoutingDataSource去实现determineCurrentLookupKey()方法，然后自己来切换字符串告诉this.resolvedDataSources.get(lookupKey);方法这个lookupKey是谁？(也就是这个字符所对应的数据源的key(请看mybatis-context.xml配置40行注入defaultTargetDataSource和targetDataSources的值,通过‘lookupKey’字符串切换，spring注入的数据源对象.package com.common.readwriteseparate;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface DataSource {String value();
}package com.common.readwriteseparate;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;public class DynamicDataSource extends AbstractRoutingDataSource{@Overrideprotected Object determineCurrentLookupKey() {String dataSouceKey = DynamicDataSourceHolder.getDataSouce();return dataSouceKey;}}package com.common.readwriteseparate;public class DynamicDataSourceHolder {public static final ThreadLocal<String> holder = new ThreadLocal<String>();public static void putDataSource(String name) {holder.set(name);}public static String getDataSouce() {return holder.get();}
}在DynamicDataSource的定义知道，返回的是DynamicDataSourceHolder.getDataSouce()值，我们需要在程序运行时调用DynamicDataSourceHolder.putDataSource()方法，对dataSouceKey数据源key赋值。
package com.common.readwriteseparate;import java.lang.reflect.Method;import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;public class DataSourceAspect {//log private static final Logger LOG = LoggerFactory.getLogger(DataSourceAspect.class);public void before(JoinPoint point) {Object target = point.getTarget();String method = point.getSignature().getName();Class<?>[] classz = target.getClass().getInterfaces();Class<?>[] parameterTypes = ((MethodSignature) point.getSignature()).getMethod().getParameterTypes();try {Method methodRefRes = classz[0].getMethod(method, parameterTypes);if (methodRefRes != null && methodRefRes.isAnnotationPresent(DataSource.class)) {DataSource data = methodRefRes.getAnnotation(DataSource.class);DynamicDataSourceHolder.putDataSource(data.value());LOG.info("\n************************************************\n" + "\t~~~DB:: " + data.value() + "\n************************************************");}} catch (Exception e) {LOG.error("数据源失败切面获取异常:" + e.getMessage(), e);}}
}
①spring的配置(spring-context.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:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop"xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <!-- 使用annotation 自动注册bean,并检查@Required,@Autowired的属性已被注入 --><context:component-scan base-package="com.user.service,com.user.dao,com.user.bean,com.user.xml" /><!-- 引入属性配置文件 --><bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:database.properties" /> </bean> <!--或 <context:property-placeholder location="classpath*:*.properties" /> -->
</beans> <?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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd" default-lazy-init="true"><description>MyBatis的数据库持久层配置/配置主-从数据源</description><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource" /><!-- 自动扫描entity目录, 省掉Configuration.xml里的手工配置 --><property name="mapperLocations" value="classpath*:com/user/xml/*.xml" /><property name="configLocation" value="classpath:mybatis-config.xml"></property></bean><!-- 扫描dao --><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.user.dao" /><property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" /></bean><!-- 配置数据库注解aop --><aop:aspectj-autoproxy /><bean id="dataSourceAspect" class="com.common.readwriteseparate.DataSourceAspect" /><aop:config><aop:aspect id="c" ref="dataSourceAspect"><aop:pointcut id="tx" expression="execution(* com.user.dao.*.*(..))" /><aop:before pointcut-ref="tx" method="before" /></aop:aspect></aop:config><!-- 主-从数据源路由 --><bean id="dataSource" class="com.common.readwriteseparate.DynamicDataSource"><property name="targetDataSources"> <map key-type="java.lang.String"> <!-- write --><entry key="master" value-ref="masterDataSource"/> <!-- read --><entry key="slave" value-ref="slaveDataSource"/> </map> </property> <property name="defaultTargetDataSource" ref="masterDataSource"/> </bean>
</beans><?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration> <typeAliases><package name="com.user.bean"/></typeAliases>
</configuration> #mysql-Used to verify the effectiveness of the database connection
validationQuery=SELECT 1
jdbc.initialSize=5
jdbc.maxActive=20
jdbc.maxWait=60000
jdbc.poolPreparedStatements=false
jdbc.poolMaximumIdleConnections=0
jdbc.driverClassName=org.gjt.mm.mysql.Driver
#1.tms business. 2.The db level optimization,data concurrency,desirable.
master.jdbc.url=jdbc:mysql://your ip:3306/master?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull
slave.jdbc.url=jdbc:mysql://your ip:3306/slave?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull
jdbc.username=username
jdbc.password=password
<?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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:aop="http://www.springframework.org/schema/aop"xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd" default-lazy-init="true"><description>配置主-从数据源</description><!-- 配置数据源-Master --><bean name="masterDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"><property name="driverClassName" value="${jdbc.driverClassName}" /><property name="url" value="${master.jdbc.url}" /><property name="username" value="${jdbc.username}" /><property name="password" value="${jdbc.password}" /><!-- 初始化连接大小 --><property name="initialSize" value="0" /><!-- 连接池最大使用连接数量 --><property name="maxActive" value="20" /><!-- 连接池最大空闲 error:maxIdle is deprecated --><!-- <property name="maxIdle" value="20" /> --><!-- 连接池最小空闲 --><property name="minIdle" value="0" /><!-- 获取连接最大等待时间 --><property name="maxWait" value="60000" /><!-- <property name="poolPreparedStatements" value="true" /> <property name="maxPoolPreparedStatementPerConnectionSize" value="33" /> --><property name="validationQuery" value="${validationQuery}" /><property name="testOnBorrow" value="false" /><property name="testOnReturn" value="false" /><property name="testWhileIdle" value="true" /><!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 --><property name="timeBetweenEvictionRunsMillis" value="60000" /><!-- 配置一个连接在池中最小生存的时间，单位是毫秒 --><property name="minEvictableIdleTimeMillis" value="25200000" /><!-- 打开removeAbandoned功能 --><property name="removeAbandoned" value="true" /><!-- 1800秒，也就是30分钟 --><property name="removeAbandonedTimeout" value="1800" /><!-- 关闭abanded连接时输出错误日志 --><property name="logAbandoned" value="true" /><!-- 监控数据库 --><!-- <property name="filters" value="stat" /> --><property name="filters" value="mergeStat" /></bean><!-- 配置数据源-Slave --><bean name="slaveDataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"><property name="driverClassName" value="${jdbc.driverClassName}" /><property name="url" value="${slave.jdbc.url}" /><property name="username" value="${jdbc.username}" /><property name="password" value="${jdbc.password}" /><!-- 初始化连接大小 --><property name="initialSize" value="0" /><!-- 连接池最大使用连接数量 --><property name="maxActive" value="20" /><!-- 连接池最大空闲 error:maxIdle is deprecated --><!-- <property name="maxIdle" value="20" /> --><!-- 连接池最小空闲 --><property name="minIdle" value="0" /><!-- 获取连接最大等待时间 --><property name="maxWait" value="60000" /><!-- <property name="poolPreparedStatements" value="true" /> <property name="maxPoolPreparedStatementPerConnectionSize" value="33" /> --><property name="validationQuery" value="${validationQuery}" /><property name="testOnBorrow" value="false" /><property name="testOnReturn" value="false" /><property name="testWhileIdle" value="true" /><!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 --><property name="timeBetweenEvictionRunsMillis" value="60000" /><!-- 配置一个连接在池中最小生存的时间，单位是毫秒 --><property name="minEvictableIdleTimeMillis" value="25200000" /><!-- 打开removeAbandoned功能 --><property name="removeAbandoned" value="true" /><!-- 1800秒，也就是30分钟 --><property name="removeAbandonedTimeout" value="1800" /><!-- 关闭abanded连接时输出错误日志 --><property name="logAbandoned" value="true" /><!-- 监控数据库 --><!-- <property name="filters" value="stat" /> --><property name="filters" value="mergeStat" /></bean>
</beans><?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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:aop="http://www.springframework.org/schema/aop"xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd" default-lazy-init="true"><description>配置事物</description><!-- 注解方式配置事物 --><tx:annotation-driven transaction-manager="transactionManager" /><!-- 配置事务管理器 --><bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource" /></bean><aop:config><aop:pointcut expression="(execution(* com.user.service.*.* (..)))" id="pointcut" /><aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut" /></aop:config><!-- 事务控制 --><tx:advice id="txAdvice" transaction-manager="transactionManager"><tx:attributes><tx:method name="load*" read-only="true" /><tx:method name="get*" read-only="true" /><tx:method name="create*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><tx:method name="save*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><tx:method name="update*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><tx:method name="insert*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><tx:method name="delete*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><tx:method name="schedule*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><tx:method name="do*" propagation="REQUIRED" rollback-for="java.lang.Exception" /><!-- 一个事务涉及一个数据源不能在事务内部去切换数据源成功，所以对多数据源的方法暂不开启事务~分布式事务 --><!-- <tx:method name="crud*" propagation="REQUIRED" rollback-for="java.lang.Exception" /> --><!-- <tx:method name="*" /> --></tx:attributes></tx:advice>
</beans># Set root category priority to INFO and its only appender to CONSOLE.
log4j.rootLogger=info, STDOUT, FILEOUT
# CONSOLE is set to be a ConsoleAppender using a PatternLayout.
log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender
log4j.appender.STDOUT.encoding=UTF-8
log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.STDOUT.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m %n# FILEOUT is set to be a File appender using a PatternLayout.
log4j.appender.FILEOUT=org.apache.log4j.RollingFileAppender
#tomcat1
#log4j.appender.FILEOUT.File=/home/logs/timespacexstar1/timespacexstar.log
#tomcat2
log4j.appender.FILEOUT.File=/home/logs/mydemoweb/mydemoweb.log
log4j.appender.FILEOUT.MaxFileSize=5MB
log4j.appender.FILEOUT.MaxBackupIndex=10
log4j.appender.FILEOUT.encoding=UTF-8
log4j.appender.FILEOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.FILEOUT.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m %n
# SQL
log4j.logger.java.sql.ResultSet=debug
log4j.logger.org.apache=debug
log4j.logger.java.sql.Connection=debug
log4j.logger.java.sql.Statement=debug
log4j.logger.java.sql.PreparedStatement=debug①：dao层：
package com.user.dao;import com.common.readwriteseparate.DataSource;
import com.user.bean.Member;public interface MemberMapper {@DataSource("master")int deleteByPrimaryKey(Integer id);@DataSource("master")int insert(Member record);@DataSource("master")int insertSelective(Member record);@DataSource("master")int updateByPrimaryKeySelective(Member record);@DataSource("master")int updateByPrimaryKey(Member record);@DataSource("slave")Member selectByPrimaryKey(Integer id);
}package com.user.service;import com.user.bean.Member;public interface MemberService {Member crudMember(Member member);
}
package com.user.service.impl;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.interceptor.TransactionAspectSupport;import com.user.bean.Member;
import com.user.dao.MemberMapper;
import com.user.service.MemberService;@Service("memberService")
public class MemberServiceImpl implements MemberService {//log private static final Logger LOG = LoggerFactory.getLogger(MemberServiceImpl.class);@Autowiredprivate MemberMapper memeberDao;@Overridepublic Member crudMember(Member member) {Member resMember = null;try {resMember = memeberDao.selectByPrimaryKey(member.getId());LOG.info(member.getId() + "查询成功~");memeberDao.insert(member);LOG.info(member.getUsername() + "注册成功~");} catch (Exception e) {LOG.error("用户id："+member.getId()+"保存和查询失败~~~" + e.getMessage(), e);TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();}return resMember;}}junit测试代码：
package com.user.test;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import com.common.definition.DictionaryDefinition;
import com.user.bean.Member;
import com.user.service.MemberService;@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:spring-context.xml","classpath:datasource-context.xml","classpath:mybatis-context.xml","classpath:transaction-context.xml"})
public class UserTest {//log private static final Logger LOG = LoggerFactory.getLogger(UserTest.class);@Autowiredprivate MemberService memberService;/*** 主从分离测试，非支持事务* */@Testpublic void crudTraM(){Member member = new Member();member.setId(2);member.setUsername("Tony5");member.setPassword("12345678");member.setStatus(DictionaryDefinition.LOGIN_NORMAL);Member member1 = memberService.crudMember(member);if(member1 != null){LOG.info("结果~~：" + member1.getUsername());}else{LOG.info("主从事物回滚测试失败数据为空");}}
}效果：master插入前：
后：
slave前后不变：
junit代码测试结果log：
2016-04-11 18:48:32 [ main:2195 ] - [ INFO ]
************************************************~~~DB:: slave
************************************************
2016-04-11 18:48:32 [ main:2879 ] - [ INFO ] 2查询成功~
2016-04-11 18:48:32 [ main:2880 ] - [ INFO ]
************************************************~~~DB:: master
************************************************
2016-04-11 18:48:32 [ main:2977 ] - [ INFO ] Tony5注册成功~
2016-04-11 18:48:32 [ main:2977 ] - [ INFO ] 结果~~：kekeai A:spring事务的默然配置：
<tx:method name="*" />
默认意义：
①：事务传播设置是 REQUIRED
②：隔离级别是数据库 DEFAULT
③：事务是支持 读/写
④：事务超时默认是依赖于事务系统的，或者事务超时没有被支持。
⑤：任何 RuntimeException 将触发事务回滚，但是任何 checked Exception 将不触发事务回滚
<tx:method/> 有关事务自定义的设置：
源代码：Spring实现数据库读写分离
数据库sql：db_rw_separate.sql
附录：
web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns="http://java.sun.com/xml/ns/javaee"xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"version="3.0"><display-name>Archetype Created Web Application</display-name><!-- Spring监听器 --><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><context-param><param-name>contextConfigLocation</param-name><param-value>classpath*:*-context.xml</param-value></context-param><!-- 编码utf-8 --><filter><filter-name>charFilter</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>UTF-8</param-value></init-param></filter><filter-mapping><filter-name>charFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping><servlet><servlet-name>springMvc</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:spring-mvc.xml</param-value></init-param></servlet><servlet-mapping><servlet-name>springMvc</servlet-name><url-pattern>/</url-pattern></servlet-mapping><welcome-file-list><welcome-file>/index.jsp</welcome-file></welcome-file-list><!-- 配置SESSION超时，单位是分钟 --><session-config><session-timeout>45</session-timeout></session-config></web-app>
<?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:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <!-- 自动扫描该包，使SpringMVC认为包下用了@controller注解的类是控制器 --> <context:component-scan base-package="com.ourtimes.controller" /> <!--避免IE执行AJAX时，返回JSON出现下载文件 --> <bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>text/html;charset=UTF-8</value> </list> </property> </bean> <!-- 启动SpringMVC的注解功能，完成请求和注解POJO的映射 --> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> <property name="messageConverters"> <list> <ref bean="mappingJacksonHttpMessageConverter" /> <!-- JSON转换器 --> </list> </property> </bean> <!-- 定义跳转的文件的前后缀 ，视图模式配置--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 这里的配置我的理解是自动给后面action的方法return的字符串加上前缀和后缀，变成一个 可用的url地址 --> <property name="prefix" value="/WEB-INF/views/" /> <property name="suffix" value=".jsp" /> </bean> <!-- 配置文件上传，如果没有使用文件上传可以不用配置，当然如果不配，那么配置文件中也不必引入上传组件包 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 默认编码 --> <property name="defaultEncoding" value="utf-8" /> <!-- 文件大小最大值 --> <property name="maxUploadSize" value="10485760000" /> <!-- 内存中的最大值 --> <property name="maxInMemorySize" value="40960" /> </bean> </beans> 这篇关于Spring实现数据库读写分离/spring事务配置解释(Annotation/Spring AOP/Reflection)的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
