首先需要建立两个库进行测试，我这里使用的是master_test和slave_test两个库，两张库都有一张同样的表（偷懒），表名 t_user
字段名 | 类型 | 备注 |
|---|---|---|
id | int | 主键自增ID |
name | varchar | 名称 |
表中分别添加两条不同数据，方便测试 主数据库记录name为xiaobin，从库为xiaoliu。
目录结构
开始使用Springboot 整合mybatis，首先引入pom文件。
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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.4.RELEASE</version>
</parent>
<groupId>com.xiaobin</groupId>
<artifactId>mysql_master_slave</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<java.version>1.8</java.version>
<lombok.version>1.18.6</lombok.version>
<mybatis.version>1.3.2</mybatis.version>
<lombox.version>1.18.6</lombox.version>
</properties>
<dependencies>
<!-- 添加web启动坐标 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 添加lombok工具坐标 -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
</dependency>
<!-- 添加springboot 测试坐标 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
<!-- 添加lombox 测试坐标 -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombox.version}</version>
</dependency>
<!-- 添加mybatis依赖坐标 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>${mybatis.version}</version>
</dependency>
<!-- 添加mysql驱动器坐标 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- 添加druid数据源坐标 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.10</version>
</dependency>
<!-- 添加AOP坐标 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
</dependencies>
</project>动态数据源配置
这里使用的数据源为druid，实现数据源之间的切换用@DataSource自定义注解，配置Aop进行切换 application.yml 配置文件。
代码语言：javascript复制spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
druid:
xiaobin-master: # 主数据源
driverClassName: com.mysql.jdbc.Driver
username: root
password: root
url: jdbc:mysql://localhost:3306/master_test?serverTimezone=GMT+8&useUnicode=true&characterEncoding=utf8
xiaobin-slave: # 从数据源
driverClassName: com.mysql.jdbc.Driver
username: root
password: root
url: jdbc:mysql://localhost:3306/slave_test?serverTimezone=GMT+8&useUnicode=true&characterEncoding=utf8
mybatis:
mapper-locations: classpath:mapper/*.xml多数据源配置类
代码语言：javascript复制@Configuration
@Component
public class DynamicDataSourceConfig {
@Bean
@ConfigurationProperties("spring.datasource.druid.xiaobin-master")
public DataSource xiaobinMasterDataSource(){
return DruidDataSourceBuilder.create().build();
}
@Bean
@ConfigurationProperties("spring.datasource.druid.xiaobin-slave")
public DataSource xiaobinSlaveDataSource(){
return DruidDataSourceBuilder.create().build();
}
@Bean
@Primary
public DynamicDataSource dataSource(DataSource xiaobinMasterDataSource, DataSource xiaobinSlaveDataSource) {
Map<Object, Object> targetDataSources = new HashMap<>();
targetDataSources.put("xiaobin-master",xiaobinMasterDataSource);
targetDataSources.put("xiaobin-slave", xiaobinSlaveDataSource);
return new DynamicDataSource(xiaobinMasterDataSource, targetDataSources);
}
}动态数据源切换类
代码语言：javascript复制public class DynamicDataSource extends AbstractRoutingDataSource {
private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) {
super.setDefaultTargetDataSource(defaultTargetDataSource);
super.setTargetDataSources(targetDataSources);
super.afterPropertiesSet();
}
@Override
protected Object determineCurrentLookupKey() {
return getDataSource();
}
public static void setDataSource(String dataSource) {
contextHolder.set(dataSource);
}
public static String getDataSource() {
return contextHolder.get();
}
public static void clearDataSource() {
contextHolder.remove();
}
}
自定义@DataSource注解
在需要切换数据的Dao添加此注解
代码语言：javascript复制/**
* 备注：自定义数据源选择注解
**/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
String name() default "";
}
Aop切面类配置
代码语言：javascript复制@Aspect
@Component
public class DataSourceAspect {
@Pointcut("@annotation(com.xiaobin.annotation.DataSource)")
public void dataSourcePointCut() {
}
@Around("dataSourcePointCut()")
public Object around(ProceedingJoinPoint point) throws Throwable {
MethodSignature signature = (MethodSignature) point.getSignature();
Method method = signature.getMethod();
DataSource dataSource = method.getAnnotation(DataSource.class);
if(dataSource == null){
DynamicDataSource.setDataSource("xiaobin-master");
}else {
DynamicDataSource.setDataSource(dataSource.name());
}
try {
return point.proceed();
} finally {
DynamicDataSource.clearDataSource();
}
}
}启动配置注解信息，重要（不然运行会报错）
代码语言：javascript复制@SpringBootApplication(exclude= {DataSourceAutoConfiguration.class})
@MapperScan(basePackages = "com.xiaobin.mapper")
@Import({DynamicDataSourceConfig.class})
public class StartApp {
public static void main(String[] args) {
SpringApplication.run(StartApp.class);
}
}测试controller
代码语言：javascript复制@RestController
@RequestMapping
public class UserController {
@Autowired
private UserMapper userMapper;
@GetMapping("/{name}/list")
public List<TUser> list(@PathVariable("name")String name){
if(name.equals("master")){
return userMapper.queryAllWithMaster();
}else{
return userMapper.queryAllWithSlave();
}
}
}效果图
更具路径传值，进行主从数据源切换
来源：https://juejin.im/post/5d8705e65188253f4b629f47
