那麼現在這篇是Springboot操作多資料源,我采用一貫的優雅方式實作:注解 ,切點的方式實作。
進入主題,
先看看這次案例項目的最終目錄結構:
然後我這次準備的兩個不同的資料庫(多個也可以),
一個是game_message , 一個是 game_message_cluster 。
首先先看看我們這次用到的jar,pom.xml(相關jar的作用都有相關的注釋):
<?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 https://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>2.1.7.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<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>
<!--mysql連接配接-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!--Druid連接配接池-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.9</version>
</dependency>
<!--整合mybatis-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.0</version>
</dependency>
<!--AOP-->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.9</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.8.9</version>
</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>
</project>
然後接下來是application.yml檔案:
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.jdbc.Driver
druid:
#第一個資料源連接配接資訊
one:
url: jdbc:mysql://localhost:3306/game_message?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
username: root
password: root
#第二個資料源連接配接資訊
two:
url: jdbc:mysql://localhost:3306/game_message_cluster?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
username: root
password: root
#資料庫連接配接池資訊
initial-size: 10
max-active: 100
min-idle: 10
max-wait: 60000
pool-prepared-statements: true
max-pool-prepared-statement-per-connection-size: 20
time-between-eviction-runs-millis: 60000
min-evictable-idle-time-millis: 300000
validation-query: SELECT 1 FROM DUAL
test-while-idle: true
test-on-borrow: false
test-on-return: false
stat-view-servlet:
enabled: true
url-pattern: /druid/*
filter:
stat:
log-slow-sql: true
slow-sql-millis: 1000
merge-sql: true
wall:
config:
multi-statement-allow: true
#配置下項目端口
server:
port: 8023
#mybatis掃描檔案路徑
mybatis:
config-location: classpath:mybatis/mybatis-config.xml
mapper-locations: classpath:mybatis/mapper/*.xml
#将日志檔案生成到系統盤路徑
logging:
path: F:\\logtest\\log
#簡單設定一下日志等級
level:
web: debug
接下來我們羅列下資料源的名字,這裡簡單用ONE 、TWO 表示,DataSourceNames.java:
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
public interface DataSourceNames {
String ONE = "ONE";
String TWO = "TWO";
}
接着創一個自定義注解,作為aop切點使用,DataSource.java:
import java.lang.annotation.*;
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface DataSource {
String value() default DataSourceNames.ONE; //預設值為ONE,因為後面我們選擇配置這個ONE為預設資料庫
}
然後是配置AOP切點,DataSourceAspect.java:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.Ordered;
import org.springframework.stereotype.Component;
import java.lang.reflect.Method;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
@Aspect
@Component
public class DataSourceAspect implements Ordered {
protected Logger logger = LoggerFactory.getLogger(getClass());
/**
* 切點: 所有配置 DataSource 注解的方法
*/
@Pointcut("@annotation(com.example.demo.config.DataSource)")
public void dataSourcePointCut() {}
@Around("dataSourcePointCut()")
public Object around(ProceedingJoinPoint point) throws Throwable {
MethodSignature signature = (MethodSignature) point.getSignature();
Method method = signature.getMethod();
DataSource ds = method.getAnnotation(DataSource.class);
// 通過判斷 DataSource 中的值來判斷目前方法應用哪個資料源
DynamicDataSource.setDataSource(ds.value());
logger.info("AOP切換資料源成功,資料源為: " + ds.value());
logger.info("set datasource is " + ds.value());
try {
return point.proceed();
} finally {
DynamicDataSource.clearDataSource();
logger.info("clean datasource");
}
}
@Override
public int getOrder() {
return 1;
}
}
到這裡切點AOP的相關配置已經完畢了,接下來到核心的動态資料源配置。
先建立手動切換資料源的核心方法類,DynamicDataSource.java:
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import javax.sql.DataSource;
import java.util.Map;
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
public class DynamicDataSource extends AbstractRoutingDataSource {
private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
/**
* 配置DataSource, defaultTargetDataSource為主資料庫
*/
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();
}
}
然後是用于讀取配置資訊多資料源,并将其載入的類,DynamicDataSourceConfig.java:
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
@Configuration
public class DynamicDataSourceConfig {
/**
* 建立 DataSource Bean
* */
@Bean
@ConfigurationProperties("spring.datasource.druid.one")
public DataSource oneDataSource(){
DataSource dataSource = DruidDataSourceBuilder.create().build();
return dataSource;
}
@Bean
@ConfigurationProperties("spring.datasource.druid.two")
public DataSource twoDataSource(){
DataSource dataSource = DruidDataSourceBuilder.create().build();
return dataSource;
}
/**
* 将資料源資訊載入targetDataSources
* */
@Bean
@Primary
public DynamicDataSource dataSource(DataSource oneDataSource, DataSource twoDataSource) {
Map<Object, Object> targetDataSources = new HashMap<>(2);
targetDataSources.put(DataSourceNames.ONE, oneDataSource);
targetDataSources.put(DataSourceNames.TWO, twoDataSource);
// 如果還有其他資料源,可以按照資料源one和two這種方法去進行配置,然後在targetDataSources中繼續添加
System.out.println("加載的資料源DataSources:" + targetDataSources);
//DynamicDataSource(預設資料源,所有資料源) 第一個指定預設資料庫
return new DynamicDataSource(oneDataSource, targetDataSources);
}
}
然後是mapper層,MessageboardMapper.java:
import com.example.demo.pojo.Messageboard;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface MessageboardMapper {
Messageboard selectByPrimaryKey(Integer id);
}
然後對應的MessageboardMapper.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.example.demo.mapper.MessageboardMapper" >
<resultMap id="BaseResultMap" type="com.example.demo.pojo.Messageboard" >
<id column="id" property="id" jdbcType="INTEGER" />
<result column="userName" property="username" jdbcType="VARCHAR" />
<result column="message" property="message" jdbcType="VARCHAR" />
</resultMap>
<sql id="Base_Column_List" >
id, userName, message
</sql>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
select
<include refid="Base_Column_List" />
from messageboard
where id = #{id,jdbcType=INTEGER}
</select>
</mapper>
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="useGeneratedKeys" value="true"/>
<setting name="useColumnLabel" value="true"/>
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
</configuration>
(想了解更多的mybatis配置項,
接下來是較為關鍵的,就是service層,簡單建立一個DataSourceTestService.java:
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
import com.example.demo.config.DataSource;
import com.example.demo.config.DataSourceNames;
import com.example.demo.mapper.MessageboardMapper;
import com.example.demo.pojo.Messageboard;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class DataSourceTestService {
@Autowired
private MessageboardMapper messageboardMapper;
public Messageboard testMaster(Integer userId){
return messageboardMapper.selectByPrimaryKey(userId);
}
@DataSource(DataSourceNames.TWO)
public Messageboard testCluster(Integer userId){
return messageboardMapper.selectByPrimaryKey(userId);
}
}
這裡需要認真看,
@DataSource(DataSourceNames.TWO)
這個注解标記的方法就是告訴目前方法即将切換資料源,所切換的資料源就是通過切點注解傳值,方法當被調用時,就會從切點先進入AOP進行資料源切換設定。
最後,寫一個簡單的接口來進行多資料源操作測試,
我準備的兩個資料庫裡面都有一張叫表messageboard的表,裡面的資料不一樣:
然後現在用接口調一下,TestController.java:
import com.example.demo.pojo.Messageboard;
import com.example.demo.service.DataSourceTestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* @Author : JCccc
* @CreateTime : 2019/8/28
* @Description :
**/
@RestController
public class TestController {
@Autowired
DataSourceTestService dataSourceTestServiceImpl;
@RequestMapping("/testDbSource")
public void testDbSource() {
Messageboard messageboard = dataSourceTestServiceImpl.testMaster(1);
System.out.println(messageboard.toString());
Messageboard messageboard2 = dataSourceTestServiceImpl.testCluster(1);
System.out.println(messageboard2.toString());
Messageboard messageboard3 = dataSourceTestServiceImpl.testMaster(1);
System.out.println(messageboard3.toString());
}
}
将項目運作,可以看到控制台列印,資料源已經都加載了:
用postman調下接口: