SpringBoot实现多数据源、AOP、主从分离

拼搏现实的明天。 2023-02-17 02:23 17阅读 0赞

1.项目目录结构：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMzcxNzY2_size_16_color_FFFFFF_t_70][]

2.pom.xml

<?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.cxb.datasources</groupId>
    	<artifactId>springboot-datasources</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<packaging>jar</packaging>
    
    	<name>springboot-datasources</name>
    	<description>Demo project for Spring Boot</description>
    
    	<parent>
    		<groupId>org.springframework.boot</groupId>
    		<artifactId>spring-boot-starter-parent</artifactId>
    		<version>2.0.2.RELEASE</version>
    		<relativePath /> 
    	</parent>
    
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    		<java.version>1.8</java.version>
    	</properties>
    
    	<dependencies>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter</artifactId>
    		</dependency>
    
    		
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.mybatis.spring.boot</groupId>
    			<artifactId>mybatis-spring-boot-starter</artifactId>
    			<version>1.3.0</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    		</dependency>
    		<dependency>  
                <groupId>org.springframework.boot</groupId>  
                <artifactId>spring-boot-starter-aop</artifactId>  
            </dependency>
    
    		<dependency>
    			<groupId>org.projectlombok</groupId>
    			<artifactId>lombok</artifactId>
    		</dependency>
    
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-test</artifactId>
    			<scope>test</scope>
    		</dependency>
    	</dependencies>
    
    	<build>
    		<plugins>
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    		</plugins>
    	</build>
    
    	<repositories>
    		<repository>
    			<id>spring-snapshots</id>
    			<name>Spring Snapshots</name>
    			<url>https://repo.spring.io/snapshot</url>
    			<snapshots>
    				<enabled>true</enabled>
    			</snapshots>
    		</repository>
    		<repository>
    			<id>spring-milestones</id>
    			<name>Spring Milestones</name>
    			<url>https://repo.spring.io/milestone</url>
    			<snapshots>
    				<enabled>false</enabled>
    			</snapshots>
    		</repository>
    	</repositories>
    
    	<pluginRepositories>
    		<pluginRepository>
    			<id>spring-snapshots</id>
    			<name>Spring Snapshots</name>
    			<url>https://repo.spring.io/snapshot</url>
    			<snapshots>
    				<enabled>true</enabled>
    			</snapshots>
    		</pluginRepository>
    		<pluginRepository>
    			<id>spring-milestones</id>
    			<name>Spring Milestones</name>
    			<url>https://repo.spring.io/milestone</url>
    			<snapshots>
    				<enabled>false</enabled>
    			</snapshots>
    		</pluginRepository>
    	</pluginRepositories>
    
    
    </project>

3.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>
      <setting name="mapUnderscoreToCamelCase" value="true"/>
     </settings>
    </configuration>

4.application.yml

##多数据源
    datasource:
      #主库
      master:
        jdbcUrl: jdbc:mysql://localhost:3306/master_base?useUnicode=true&characterEncoding=utf-8
        username: root
        password: 123456
        driver-class-name: com.mysql.jdbc.Driver
      #从库
      slave:
        #并非url而是jdbcUrl(因为这个在获取数据源时一直报错，看了DataSource的属性才知道是jdbcUrl)
        jdbcUrl: jdbc:mysql://localhost:3306/slave_base?useUnicode=true&characterEncoding=utf-8
        username: root
        password: 123456
        driver-class-name: com.mysql.jdbc.Driver
          
    ##mybatis
    mybatis:
      mapper-locations: classpath:mapper/*.xml
      type-aliases-package: com.cxb.database.domain
      check-config-location: true
      config-location: classpath:mybatis-config.xml

5.TestMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
    <mapper namespace="com.cxb.database.mapper.TestMapper">
    
        <select id="queryCount" resultType="Integer">
        	SELECT count(1) FROM t_user
        </select>  
        
    </mapper>

6.TestController

package com.cxb.database.controller;
    
    import com.cxb.database.service.TestService;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class TestController {
    	
    	protected static final Logger logger = LoggerFactory.getLogger(TestController.class);
    	
    	@Autowired
    	private TestService testService;
    	
    	@RequestMapping("/test")
    	public String index() {
    		logger.debug("测试信息：{}","welcome log world");
    		return "主表："+testService.queryCountByMester();
    	}
    	
    	@RequestMapping("/test1")
    	public String test(@RequestParam String name) {
    		return "从表："+testService.queryCountBySavle(name);
    	}
    	
    	
    }

7.DataSourceAspect

package com.cxb.database.datasource;
    
    import java.lang.reflect.Method;
    
    import org.aspectj.lang.JoinPoint;
    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.core.annotation.Order;
    import org.springframework.stereotype.Component;  
    
    /**
     * AOP根据注解给上下文赋值
     */
    @Aspect
    // 设置AOP执行顺序(需要在事务之前，否则事务只发生在默认库中)
    @Order(1)
    @Component
    public class DataSourceAspect {
    	
    	private Logger logger = LoggerFactory.getLogger(this.getClass());
    	
    	//切点
    	@Pointcut("execution(* com.cxb.database.service..*.*(..)))")
    	public void aspect() { }
    	
    	@Before("aspect()")
    	private void before(JoinPoint point) {
    		Object target = point.getTarget();  
            String method = point.getSignature().getName();  
            Class<?> classz = target.getClass();  
            Class<?>[] parameterTypes = ((MethodSignature) point.getSignature())  
                    .getMethod().getParameterTypes();  
            try {  
                Method m = classz.getMethod(method, parameterTypes);  
                if (m != null && m.isAnnotationPresent(MyDataSource.class)) {  
                	MyDataSource data = m.getAnnotation(MyDataSource.class);  
                    JdbcContextHolder.putDataSource(data.value().getName()); 
                    logger.info("===============上下文赋值完成:{}",data.value().getName());
                }  
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
            
    	}
    }

8.DataSourceConfig

package com.cxb.database.datasource;
    
    import java.util.HashMap;
    import java.util.Map;
    
    import javax.sql.DataSource;
    
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.boot.jdbc.DataSourceBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    
    /**
     * 数据源配置
     */
    @Configuration
    public class DataSourceConfig {
    
    	@Bean(name = "master")
    	@ConfigurationProperties(prefix = "datasource.master") 
    	public DataSource dataSource1() {
    		System.out.println("主配");
    		return DataSourceBuilder.create().build();
    	}
    
    	@Bean(name = "slave")
    	@ConfigurationProperties(prefix = "datasource.slave") 
    	public DataSource dataSource2() {
    		System.out.println("从配");
    		return DataSourceBuilder.create().build();
    	}
    	
    	@Bean(name="dynamicDataSource")
    	@Primary	//优先使用，多数据源
    	public DataSource dataSource() {
    		DynamicDataSource dynamicDataSource = new DynamicDataSource();
    		DataSource master = dataSource1();
    		DataSource slave = dataSource2();
    		//设置默认数据源
    		dynamicDataSource.setDefaultTargetDataSource(master);	
    		//配置多数据源
    		Map<Object,Object> map = new HashMap<>();
    		map.put(DataSourceType.Master.getName(), master);	//key需要跟ThreadLocal中的值对应
    		map.put(DataSourceType.Slave.getName(), slave);
    		dynamicDataSource.setTargetDataSources(map);			
    		return dynamicDataSource;
    	}
    	
    }

9.DataSourceType

package com.cxb.database.datasource;
    
    public enum DataSourceType {
    
    	// 主表
    	Master("master"),
    	// 从表
    	Slave("slave");
    
    	private String name;
    
    	private DataSourceType(String name) {
    		this.name = name;
    	}
    
    	public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    }

10.DynamicDataSource

package com.cxb.database.datasource;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
    
    public class DynamicDataSource extends AbstractRoutingDataSource {
    
    	private Logger logger = LoggerFactory.getLogger(this.getClass());
    	
    	@Override
    	protected Object determineCurrentLookupKey() {
    		logger.info("数据源为{}",JdbcContextHolder.getDataSource());
    		return JdbcContextHolder.getDataSource();
    	}
    	
    }

11.JdbcContextHolder

package com.cxb.database.datasource;
    /**
     * 动态数据源的上下文 threadlocal
     */
    public class JdbcContextHolder {
    	
    	private final static ThreadLocal<String> local = new ThreadLocal<>();
    	
    	public static void putDataSource(String name) {
    		local.set(name);
    	}
    	
    	public static String getDataSource() {
    		return local.get();
    	}
    	
    }

12.MyDataSource

package com.cxb.database.datasource;
    
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    /**
     * 数据源选择--自定义注解
     */
    @Retention(RetentionPolicy.RUNTIME)  
    @Target(ElementType.METHOD) 
    public @interface MyDataSource {
    
    	DataSourceType value() default DataSourceType.Master;	//默认主表
    	
    }

13.TestMapper

package com.cxb.database.mapper;
    
    import org.apache.ibatis.annotations.Param;
    import org.apache.ibatis.annotations.Update;
    
    public interface TestMapper {
    
    	Integer queryCount();
    	
    	@Update("update book set stock = stock - 1 where name = #{name} and stock != 0")
    	Integer updateBookByName(@Param("name") String name);
    
    }

14.TestService

package com.cxb.database.service;
    
    public interface TestService {
    
    	Integer queryCountByMester();
    	
    	Integer queryCountBySavle(String name);
    	
    }

15.TestServiceImpl

package com.cxb.database.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.annotation.Transactional;
    
    import com.cxb.database.datasource.DataSourceType;
    import com.cxb.database.datasource.MyDataSource;
    import com.cxb.database.mapper.TestMapper;
    import com.cxb.database.service.TestService;
    
    @Service
    public class TestServiceImpl implements TestService {
    
        Logger logger = LoggerFactory.getLogger(this.getClass());
    
        @Autowired
        private TestMapper testMapper;
    
        @Override
        @MyDataSource(DataSourceType.Master)
        public Integer queryCountByMester() {
            return testMapper.queryCount();
        }
    
        @Override
        @MyDataSource(DataSourceType.Slave)
        @Transactional
        public Integer queryCountBySavle(String name) {
            //测试事务
            Integer rows = testMapper.updateBookByName(name);
            if (rows <= 0) {
                logger.info("更新小于1 执行回滚");
                throw new RuntimeException();
            }
            return rows;
        }
    
    }

16.Application

package com.cxb.database;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
    import org.springframework.transaction.annotation.EnableTransactionManagement;
    
    @SpringBootApplication(exclude = {
            DataSourceAutoConfiguration.class
    })
    //设置事务执行顺序(需要在切换数据源之后，否则只走主库)
    @EnableTransactionManagement(order = 2)
    @MapperScan(basePackages = "com.cxb.database.mapper")
    public class Application {
    
    	public static void main(String[] args) {
    		SpringApplication.run(Application.class, args);
    	}
    }

最后测试：

![20200610211020491.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMzcxNzY2_size_16_color_FFFFFF_t_70 1][]

**[代码下载][Link 1]**

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMzcxNzY2_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200610210830624.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMzcxNzY2,size_16,color_FFFFFF,t_70
[20200610211020491.png]: https://img-blog.csdnimg.cn/20200610211020491.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMzcxNzY2_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200610211038824.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMzcxNzY2,size_16,color_FFFFFF,t_70
[Link 1]: https://github.com/ChenXbFrank/springboot-datasources-demo