参考了https://www.jianshu.com/p/fddcc1a6b2d8
1、多数据源相关类
1.1 数据源路由器
AbstractRoutingDataSource 是spring提供的一个多数据源抽象类。
代码语言:javascript复制package cn.hadron.dao.datasource;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DataSourceRouter extends AbstractRoutingDataSource {
// 获取数据源名称
//spring会在使用事务的地方来调用此类的determineCurrentLookupKey()方法来获取数据源的key值。
protected Object determineCurrentLookupKey() {
return HandleDataSource.getDataSource();
}
}
1.2 数据源处理类
DataSourceRouter 类中通过HandleDataSource.getDataSource()获取数据源的key值。此方法应该和线程绑定。
代码语言:javascript复制package cn.hadron.dao.datasource;
/**
* 线程相关的数据源处理类
*
*/
public class HandleDataSource {
// 数据源名称线程池
private static final ThreadLocal<String> holder = new ThreadLocal<String>();
/**
* 设置数据源
* @param datasource 数据源名称
*/
public static void setDataSource(String datasource) {
holder.set(datasource);
}
/**
* 获取数据源
* @return 数据源名称
*/
public static String getDataSource() {
return holder.get();
}
/**
* 清空数据源
*/
public static void clearDataSource() {
holder.remove();
}
}
1.3 数据源注解类
对于spring来说,注解即简单方便且可读性也高。所以,我们也通过注解在service的方法前指定所用的数据源。我们先定义自己的注解类,其中value为数据源的key值。
代码语言:javascript复制package cn.hadron.dao.datasource;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface DataSource {
//value为数据源的key值
String value();
}
1.4 切换数据源
指定注解以后,我们可以通过AOP拦截所有service方法,在方法执行之前获取方法上的注解:即数据源的key值。
代码语言:javascript复制package cn.hadron.dao.datasource;
import java.lang.reflect.Method;
import java.text.MessageFormat;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
/**
* 切换数据源(不同方法调用不同数据源)
*/
@Aspect
@Component
@Order(1) //请注意:这里order一定要小于tx:annotation-driven的order,即先执行DataSourceAspect切面,再执行事务切面,才能获取到最终的数据源
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class DataSourceAspect {
static Logger logger = LoggerFactory.getLogger(DataSourceAspect.class);
/**
* 切入点 service包及子孙包下的所有类
*/
@Pointcut("execution(* cn.hadron.service..*.*(..))")
public void aspect() {
}
/**
* 配置前置通知,使用在方法aspect()上注册的切入点
*/
@Before("aspect()")
public void before(JoinPoint point) {
Class<?> target = point.getTarget().getClass();
MethodSignature signature = (MethodSignature) point.getSignature();
Method method = signature.getMethod() ;
DataSource dataSource = null ;
//从类初始化
dataSource = this.getDataSource(target, method) ;
//从接口初始化
if(dataSource == null){
for (Class<?> clazz : target.getInterfaces()) {
dataSource = getDataSource(clazz, method);
if(dataSource != null){
break ;//从某个接口中一旦发现注解,不再循环
}
}
}
if(dataSource != null && !StringUtils.isEmpty(dataSource.value()) ){
HandleDataSource.setDataSource(dataSource.value());
}
}
@After("aspect()")
public void after(JoinPoint point) {
//使用完记得清空
HandleDataSource.setDataSource(null);
}
/**
* 获取方法或类的注解对象DataSource
* @param target 类class
* @param method 方法
* @return DataSource
*/
public DataSource getDataSource(Class<?> target, Method method){
try {
//1.优先方法注解
Class<?>[] types = method.getParameterTypes();
Method m = target.getMethod(method.getName(), types);
if (m != null && m.isAnnotationPresent(DataSource.class)) {
return m.getAnnotation(DataSource.class);
}
//2.其次类注解
if (target.isAnnotationPresent(DataSource.class)) {
return target.getAnnotation(DataSource.class);
}
} catch (Exception e) {
e.printStackTrace();
logger.error(MessageFormat.format("通过注解切换数据源时发生异常[class={0},method={1}]:"
, target.getName(), method.getName()),e) ;
}
return null ;
}
}
2 多数据源配置
2.1 jdbc.properties
代码语言:javascript复制#============================================================================
# MySQL
#============================================================================
jdbc.mysql.driver=com.mysql.jdbc.Driver
jdbc.mysql.url=jdbc:mysql://192.168.1.160:3306/test
jdbc.mysql.username=root
jdbc.mysql.password=123456
#============================================================================
# Oracle
#============================================================================
jdbc.oracle.driver=oracle.jdbc.driver.OracleDriver
jdbc.oracle.url=jdbc:oracle:thin:@192.168.1.62:1521:ora
jdbc.oracle.username=admin
jdbc.oracle.password=123456
#============================================================================
# common setting
#============================================================================
jdbc.initialSize=5
jdbc.minIdle=5
jdbc.maxIdle=20
jdbc.maxActive=100
jdbc.maxWait=100000
jdbc.defaultAutoCommit=false
jdbc.removeAbandoned=true
jdbc.removeAbandonedTimeout=600
jdbc.testWhileIdle=true
jdbc.timeBetweenEvictionRunsMillis=60000
jdbc.numTestsPerEvictionRun=20
jdbc.minEvictableIdleTimeMillis=300000
2.2 applicationContext.xml
代码语言:javascript复制<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mybatis="http://mybatis.org/schema/mybatis-spring"
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:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="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
http://mybatis.org/schema/mybatis-spring
http://mybatis.org/schema/mybatis-spring.xsd">
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 2、配置数据库连接池 -->
<bean id="mysql" class="com.alibaba.druid.pool.DruidDataSource"
init-method="init" destroy-method="close">
<!--配置连接池属性 -->
<property name="driverClassName" value="${jdbc.mysql.driver}" />
<property name="url" value="${jdbc.mysql.url}" />
<property name="username" value="${jdbc.mysql.username}" />
<property name="password" value="${jdbc.mysql.password}" />
</bean>
<bean id="oracle" class="com.alibaba.druid.pool.DruidDataSource"
init-method="init" destroy-method="close">
<!--配置连接池属性 -->
<property name="driverClassName" value="${jdbc.oracle.driver}" />
<property name="url" value="${jdbc.oracle.url}" />
<property name="username" value="${jdbc.oracle.username}" />
<property name="password" value="${jdbc.oracle.password}" />
</bean>
<bean id="dataSource" class="cn.hadron.dao.datasource.DataSourceRouter">
<description>多数据源路由</description>
<property name="targetDataSources">
<map key-type="java.lang.String" value-type="javax.sql.DataSource">
<entry key="MYSQL" value-ref="mysql" />
<entry key="ORACLE" value-ref="oracle" />
</map>
</property>
<!-- 默认数据源,如果未指定数据源 或者指定的数据源不存在的话 默认使用这个数据源 -->
<property name="defaultTargetDataSource" ref="mysql" />
</bean>
<!--3、配置SqlSessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
</bean>
<!-- mybatis:scan会扫描cn.hadron.dao包里的所有接口当作Spring的bean配置,之后可以进行依赖注入-->
<mybatis:scan base-package="cn.hadron.dao"/>
<!-- 扫描cn.hadron包下面的java文件,有Spring的相关注解的类,则把这些类注册为Spring的bean -->
<context:component-scan base-package="cn.hadron"/>
<!-- 配置事务管理器 -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!-- 注入数据库连接池 -->
<property name="dataSource" ref="dataSource" />
</bean>
<!-- 配置基于注解的声明式事务 -->
<tx:annotation-driven transaction-manager="transactionManager"
proxy-target-class="true" order="2" />
<!-- AOP自动代理功能 -->
<aop:aspectj-autoproxy proxy-target-class="true" />
</beans>
3、多数据源使用
3.1 dao
(1)MySQL
代码语言:javascript复制package cn.hadron.dao;
import java.util.List;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import cn.hadron.bean.UserBean;
public interface UserDao {
/**
* 根据登录名和密码查询用户
* @return 找到返回User对象,没有找到返回null
* */
@Select("select * from users where username = #{username} and password = #{password}")
UserBean getUser(@Param("username") String username, @Param("password") String password);
@Select("select * from users where username = #{username}")
UserBean isExist(@Param("username") String username);
/**
* 根据ID查询用户
* @param id
* @return
*/
@Select("select * from users where id = #{id}")
@Results({
@Result(id=true,column="id",property="id"),
@Result(column="username",property="username"),
@Result(column="password",property="password"),
@Result(column="age",property="age")
})
UserBean getUserById(@Param("id") Integer id);
/**
* 查询所有用户
*/
@Select("select * from users")
List<UserBean> getAllUser();
@Insert("insert into users(username,password,age) values(#{username},#{password},#{age})")
@Options(useGeneratedKeys=true,keyProperty="id")
int saveUser(UserBean user);
@Update("update users set username = #{username},password = #{password},age = #{age} where id = #{id}")
void modifyUser(UserBean user);
}
(2)Oracle
代码语言:javascript复制package cn.hadron.dao;
import cn.hadron.bean.AttachmentBean;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import java.util.List;
public interface AttachmentDao {
@Select("select ID,SID,SOURCEENTITY,TYPE,NAME,CONTENTSIZE,FILETYPE,CONTENT from attachment")
@Results({
@Result(column="ID",property="id"),
@Result(column="SID",property="sid"),
@Result(column="SOURCEENTITY",property="sourceEntity"),
@Result(column="TYPE",property="type"),
@Result(column="NAME",property="name"),
@Result(column="CONTENTSIZE",property="contentSize"),
@Result(column="FILETYPE",property="fileType"),
@Result(column="CONTENT",property="content"),
})
List<AttachmentBean> getAttachmentList();
}
3.2 service
(1)使用MySQL数据源
代码语言:javascript复制package cn.hadron.service.impl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import cn.hadron.dao.UserDao;
import cn.hadron.dao.datasource.DataSource;
import cn.hadron.bean.UserBean;
import cn.hadron.service.UserService;
/**
* User服务层接口实现类
* @Service("userService")用于将当前类注释为一个Spring的bean,名为userService
* */
@Transactional(propagation=Propagation.REQUIRED,isolation=Isolation.DEFAULT)
@Service("userService")
@DataSource("MYSQL")
public class UserServiceImpl implements UserService {
/**
* 自动注入UserDao
* */
@Autowired
private UserDao userDao;
/**
* UserService接口login方法实现
* @see { UserService }
* */
@Transactional(readOnly=true)
@Override
public UserBean login(String username, String password) {
System.out.println("UserServiceImpl.login:" username "," password);
return userDao.getUser(username, password);
}
@Transactional(readOnly=true)
@Override
public boolean isExist(String username) {
return null!=userDao.isExist(username);
}
@Override
public boolean addUser(UserBean user) {
return 1==userDao.saveUser(user);
}
}
(2)使用Oracle数据源
代码语言:javascript复制package cn.hadron.service.impl;
import cn.hadron.bean.AttachmentBean;
import cn.hadron.dao.AttachmentDao;
import cn.hadron.dao.datasource.DataSource;
import cn.hadron.service.AttachmentService;
import oracle.sql.BLOB;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import java.io.*;
import java.sql.SQLException;
import java.util.List;
@Transactional(propagation=Propagation.REQUIRED,isolation=Isolation.DEFAULT)
@Service("attachmentService")
@DataSource("ORACLE")
public class AttachmentServiceImpl implements AttachmentService {
@Autowired
private AttachmentDao attachmentDao;
@Override
public List<AttachmentBean> getAttachmentList() {
return attachmentDao.getAttachmentList();
}
}
3.3 controller
代码语言:javascript复制package cn.hadron.controller;
import javax.servlet.http.HttpSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import cn.hadron.bean.UserBean;
import cn.hadron.service.UserService;
/**
* 处理用户请求控制器
* */
@Controller
@RequestMapping(value = "/user")
public class UserController {
/**
* 自动注入UserService
*/
@Autowired
@Qualifier("userService")
private UserService userService;
/**
* 处理/login请求
*/
@RequestMapping(value="/login.do")
public String login(String username,String password,HttpSession session){
System.out.println("###login.do");
UserBean user=userService.login(username,password);
if(user!=null){//登录成功
// 登录成功,将user对象设置到HttpSession作用范围域
session.setAttribute("user", user);
System.out.println("登录成功!");
/**
* sendRedirect对浏览器做出的响应是重新发出对另外一个URL的访问请求,
* sendRedirect的调用者与被调用者使用各自的request和response对象,属于两个独立的访问请求和响应过程
*/
return "redirect:/main.do";
}else{
//登录失败
System.out.println("登录失败!");
session.setAttribute("tip","登录失败!");
/**
* forward在服务器端内部将请求转发给另外一个资源,浏览器只知道发出了请求并得到了响应结果
* forward的调用者与被调用者之间共享相同的request对象和response对象,他们属于同一个访问请求和响应过程;
*/
return "forward:/login";
}
}
}
代码语言:javascript复制package cn.hadron.controller;
import cn.hadron.bean.AttachmentBean;
import cn.hadron.service.AttachmentService;
import cn.hadron.service.UserService;
import oracle.sql.BLOB;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import java.sql.SQLException;
import java.util.List;
@Controller
@RequestMapping(value = "/a")
public class AttachmentController {
@Autowired
@Qualifier("attachmentService")
private AttachmentService attachmentService;
@RequestMapping("testOracle.do")
public String testOracle() throws SQLException {
attachmentService.parseAttachmentList();
List<AttachmentBean> list= attachmentService.getAttachmentList();
System.out.println("共有附件数:" list.size());
return "result";
}
}
4、pom.xml
代码语言:javascript复制<?xml version="1.0" encoding="UTF-8"?>
<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.cntaiping.tpa</groupId>
<artifactId>datasource</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>datasource Maven Webapp</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<spring.version>4.3.16.RELEASE</spring.version>
<mybatis.version>3.4.5</mybatis.version>
<mybatis-spring.version>1.3.1</mybatis-spring.version>
</properties>
<dependencies>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.10</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.13</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.2.4</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<!--spring -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.5</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.oracle/ojdbc6 -->
<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc6</artifactId>
<version>11.2.0.3</version>
<type>jar</type>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.9</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<finalName>datasource</finalName>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.0.0</version>
</plugin>
<!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.7.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.20.1</version>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.0</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>