使用eclipse搭建ssm的多数据源项目
基于SSM(Spring、SpringMVC、Mybatis)搭建多数据源服务器
搭建环境介绍
本次项目开发环境是window10操作系统,开发工具使用的是Eclipse,数据库是使用SQLServer2012
项目介绍
2019年的时候,在工作中遇到了一个项目,项目需求是:将多个数据库的数据存放到本地数据库。于是就研究了一下多数据源项目的搭建方法。
步骤
第一步:写两个工具类放在utils包下
第一个类用来设置数据源变量
DataSourceContextHolder .java
package com.ssm.mf.utils;
public class DataSourceContextHolder {
private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
//设置连接数据源变量
public static void setDbType(String dbType) {
contextHolder.set(dbType);
}
//得到数据源变量
public static String getDbType() {
return ((String) contextHolder.get());
}
// 清除设置的数据源变量
public static void clearDbType() {
contextHolder.remove();
}
}
第二个类用来动态切换数据库连接:
DynamicDataSource .java
package com.ssm.mf.utils;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource{
@Override
protected Object determineCurrentLookupKey() {
return DataSourceContextHolder.getDbType();
}
}
第二步:配置 jdbc.properties
#第一个数据源
jdbc.one.driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
jdbc.one.url=jdbc:sqlserver://127.0.0.1:1433;databaseName=ONE
jdbc.one.username=sa
jdbc.one.password=123456
#第二个数据源
jdbc.two.driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
jdbc.two.url=jdbc:sqlserver://127.0.0.1:1433;databaseName=TWO
jdbc.two.username=sa
jdbc.two.password=123456
第三步:配置 mybatis-config.xml
<?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>
<settings>
<!-- 开启驼峰自动映射 -->
<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>
</configuration>
第四步:配置spring-mvc.xml
<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:aop="http://www.springframework.org/schema/aop"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.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.ssm.mf" />
<!--开启Spring注解-->
<context:annotation-config/>
<!--开启Spring MVC注解-->
<mvc:annotation-driven/>
<!-- 访问静态资源 -->
<mvc:default-servlet-handler />
<!--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>
<!-- JSON转换器 -->
<ref bean="mappingJacksonHttpMessageConverter" />
</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">
<property name="contentType" value="charset=utf-8"/>
<property name="order" value="10"/>
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<!--
配置控制器返回的字符串拼接前缀和后缀:
例如控制器方法返回的是"hello",那么url就是/WEB-INF/hello.jsp。
-->
<property name="prefix" value="/WEB-INF/" />
<property name="suffix" value=".jsp" />
</bean>
<!-- 配置文件上传 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 默认编码 -->
<property name="defaultEncoding" value="utf-8" />
<property name="maxUploadSize" value="10485760000" />
<property name="maxInMemorySize" value="40960" />
</bean>
</beans>
第五步:配置 spring-mybatis.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: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 -->
<context:component-scan base-package="com.ssm.mf" />
<!-- 引入配置文件 -->
<!-- 使用spring自带的占位符替换功能 -->
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<!-- 允许JVM参数覆盖 -->
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<!-- 忽略没有找到的资源文件 -->
<property name="ignoreResourceNotFound" value="true" />
<!-- 配置资源文件 -->
<property name="locations">
<list>
<value>classpath:jdbc.properties</value>
</list>
</property>
</bean>
<!-- 第一个数据源 -->
<bean id="oneDataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.one.driver}"></property>
<property name="url" value="${jdbc.one.url}"></property>
<property name="username" value="${jdbc.one.username}"></property>
<property name="password" value="${jdbc.one.password}"></property>
</bean>
<!-- 第二个数据源 -->
<bean id="twoDataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.two.driver}"></property>
<property name="url" value="${jdbc.two.url}"></property>
<property name="username" value="${jdbc.two.username}"></property>
<property name="password" value="${jdbc.two.password}"></property>
</bean>
<!-- 动态切换数据源 -->
<bean id="dynamicDataSource" class="com.ssm.mf.utils.DynamicDataSource">
<property name="targetDataSources">
<map key-type="java.lang.String">
<entry value-ref="oneDataSource" key="oneDataSource"></entry>
<entry value-ref="twoDataSource" key="twoDataSource"></entry>
</map>
</property>
<!-- 默认使用第一个数据源 -->
<property name="defaultTargetDataSource" ref="oneDataSource"></property>
</bean>
<!-- spring和MyBatis完美整合-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 定义数据源,数据源使用动态的数据源dynamicDataSource -->
<property name="dataSource" ref="dynamicDataSource" />
<!-- 指定mybatis全局配置文件 -->
<property name="configLocation" value="classpath:mybatis-config.xml" />
<!-- 自动扫描mapping.xml文件 -->
<property name="mapperLocations" value="classpath:com/ssm/mf/mapper/*.xml"></property>
<!-- 别名扫描包 -->
<property name="typeAliasesPackage" value="com.ssm.mf.domain" />
</bean>
<!-- DAO接口所在包名,Spring会自动查找其下的类 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.ssm.mf.*.dao" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean>
<!-- 事务管理 -->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dynamicDataSource" />
</bean>
第六步:配置 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_2_5.xsd" version="2.5">
<display-name>ssm</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>hello.html</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<!-- 指定Spring配置文件位置 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mybatis.xml</param-value>
</context-param>
<!-- Spring 上下文环境监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!--防止Spring内存溢出监听器-->
<listener>
<listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
</listener>
<!-- 编码过滤器:解决post请求参数乱码问题 -->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<!-- 指定字符集编码 -->
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 注册前端控制器 -->
<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>*.do</url-pattern>
</servlet-mapping>
</web-app>
第七步:配置pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mf</groupId>
<artifactId>ssm</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<!-- 测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- 基本包 -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.3.2</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.1</version>
</dependency>
<!-- 基本包end -->
<!-- servlet相关jar -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- servlet相关end -->
<!-- spring start -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-oxm</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>4.0.2.RELEASE</version>
</dependency>
<!-- spring相关end -->
<!-- mybatis核心包 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.0</version>
</dependency>
<!-- mybatis/spring包 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.0</version>
</dependency>
<!--MyBatis代码自动生成插件-->
<!--MyBatis Generator-->
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.2</version>
</dependency>
<!--分页插件-->
<!--https://github.com/pagehelper/Mybatis-PageHelper/blob/master/wikis/zh/HowToUse.md-->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.1.2</version>
</dependency>
<!-- 导入sqlserver数据库链接jar包 -->
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
<version>6.2.0.jre8</version>
<scope>runtime</scope>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.18</version>
<scope>compile</scope>
</dependency>
<!-- c3p0数据库连接池-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.10</version>
</dependency>
<!-- JSTL标签类 -->
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- 日志文件管理包 -->
<!-- log start -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<!-- 格式化对象,方便输出日志 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.1.41</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.7</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.7</version>
</dependency>
<!-- log end -->
<!-- Needed for JSON View -->
<!--jackson 通过@RquestBody传参时,将对象转换成json格式。通过@ResponseBody返回值时,将对象转换成json格式-->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.9.0</version>
</dependency>
<!-- 映入JSON -->
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.9</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.7.1</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.7.1</version>
</dependency>
</dependencies>
</project>
项目结构
编写控制器进行测试
我们可以看到,两个方法都调用了业务层的同一个方法,而在配置动态数据源时,我们设置了默认是第一个数据源,所以第一个控制器方法查询的是第一个数据源的内容,而第二个控制器方法将动态数据源设置成了第二个数据源,所以它查询的是第二个数据源内容
现在我们通过浏览器访问
第一个方法返回的是:
第二个方法返回的是:
通过测试,更改数据源成功