SpringBoot整合Mybatis多数据源 (AOP+注解)

SpringBoot整合Mybatis多数据源 (AOP+注解)

1、pom.xml文件(开发用的JDK 10)

<?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.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>demo</name>
<description>Demo project for Spring Boot</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>10</java.version>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!-- alibaba的druid数据库连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.10</version>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>

<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
</dependency>

<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.3</version>
</dependency>

<!-- 热部署 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

2、多数据源配置类

@Configuration
public class DataSourceConfig {

@Bean(name = "readTestDb")
@ConfigurationProperties(prefix = "spring.datasource.read-test-db")
public DataSource readTestDb() {
return DataSourceBuilder.create().build();
}

@Bean(name = "writeTestDb")
@ConfigurationProperties(prefix = "spring.datasource.write-test-db")
public DataSource writeTestDb() {
return DataSourceBuilder.create().build();
}

/**
* 动态数据源: 通过AOP在不同数据源之间动态切换
* @return
*/
@Primary
@Bean(name = "dynamicDataSource")
public DataSource dynamicDataSource() {
DynamicDataSource dynamicDataSource = new DynamicDataSource();
// 默认数据源
dynamicDataSource.setDefaultTargetDataSource(readTestDb());
// 配置多数据源
Map<Object, Object> dsMap = new HashMap<Object, Object>();
dsMap.put("readTestDb", readTestDb());
dsMap.put("writeTestDb", writeTestDb());

dynamicDataSource.setTargetDataSources(dsMap);
return dynamicDataSource;
}

/**
* 配置@Transactional注解事物
* @return
*/
@Bean
public PlatformTransactionManager transactionManager() {
return new DataSourceTransactionManager(dynamicDataSource());
}

3、数据源切换读取类

public class DataSourceContextHolder {

/**
* 默认数据源
*/
public static final String DEFAULT_DS = "readTestDb";

private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();

// 设置数据源名
public static void setDB(String dbType) {
System.out.println("切换到{"+dbType+"}数据源");
contextHolder.set(dbType);
}

// 获取数据源名
public static String getDB() {
return (contextHolder.get());
}

// 清除数据源名
public static void clearDB() {
contextHolder.remove();
}

}

4、注解类(注意：要和配置类放在同一个包下，否则会抛出找不到注解异常)

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
@Documented
public @interface DS {
String value() default "readTestDb";
}

5、动态数据源(设置数据源自动调用该类方法)

public class DynamicDataSource extends AbstractRoutingDataSource  {

@Override
protected Object determineCurrentLookupKey() {
System.out.println("数据源为"+DataSourceContextHolder.getDB());
return DataSourceContextHolder.getDB();
}

}

6、AOP

@Aspect
@Component
public class DynamicDataSourceAspect {

@Before("@annotation(DS)")
@SuppressWarnings("rawtypes")
public void beforeSwitchDS(JoinPoint point){
//获得当前访问的class
Class<?> className = point.getTarget().getClass();
//获得访问的方法名
String methodName = point.getSignature().getName();
//得到方法的参数的类型
Class[] argClass = ((MethodSignature)point.getSignature()).getParameterTypes();
String dataSource = DataSourceContextHolder.DEFAULT_DS;
try {
// 得到访问的方法对象
Method method = className.getMethod(methodName, argClass);
// 判断是否存在@DS注解
if (method.isAnnotationPresent(DS.class)) {
DS annotation = method.getAnnotation(DS.class);
// 取出注解中的数据源名
dataSource = annotation.value();
}
} catch (Exception e) {
e.printStackTrace();
}
// 切换数据源
DataSourceContextHolder.setDB(dataSource);
}

@After("@annotation(DS)")
public void afterSwitchDS(JoinPoint point){
DataSourceContextHolder.clearDB();
}
}

7、application.yml 配置文件 (和application.properties区别 可以百度一下 很详细)

spring:
datasource:
read-test-db:
jdbc-url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8
username: root
password: root
# 使用druid数据源
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver

write-test-db:
jdbc-url: jdbc:mysql://127.0.0.1:3306/writetest?useUnicode=true&characterEncoding=utf-8
username: root
password: root
# 使用druid数据源
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
jpa:
show-sql: true

mybatis:
#mapper-locations: classpath:mapping/mapper/*.xml
type-aliases-package: com.example.demo.model

8、启动类( 注解：@MapperScan 扫描mapper接口类路径 、多数据源 @SpringBootApplication这个注解是必须写的 )

@MapperScan("com.example.demo.mapper")
@SpringBootApplication(exclude = {
DataSourceAutoConfiguration.class
})
public class DemoApplication {

public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}

9、Controller( 注解：@RestController( 包含@controller、@responseBody等其他注解 所以用该注解就不用每个方法上@responseBody ) )

@RestController
public class DemoController {

@Autowired
private UserService userService;

@RequestMapping("/getRequestDBObj")
public User getRequestDBObj(HttpServletRequest request,HttpServletResponse response) {
return userService.selectByPrimaryKey(1);
}

@RequestMapping("/getRequestDbList")
public User getRequestDbList(HttpServletRequest request,HttpServletResponse response) {
return userService.selectAllUser(1);
}
}

10、Service

public interface UserService {

public User selectByPrimaryKey(Integer userId);

public User selectAllUser(Integer userId);
}

11、ServiceImpl

@Service
public class UserServiceImpl implements UserService {

@Autowired
private UserMapper userMapper;

@Override
@DS("writeTestDb")
public User selectByPrimaryKey(Integer userId) {
return userMapper.selectByPrimaryKey(userId);
}

@Override
@DS("readTestDb")
public User selectAllUser(Integer userId) {
return userMapper.selectByPrimaryKey(userId);
}

}

12、Mapper

public interface UserMapper {

@Select("SELECT user_id as userId, user_name as userName, password, phone FROM t_user WHERE user_id = #{userId}")
User selectByPrimaryKey(Integer userId);

}

13、本人 QQ 1036943655 本人萌新 有代码不对的地方 大家指教一下 也可以加好友 大家一起互相学习、互相进步