Springboot多數據源配置

時間 2020-06-19

原文原文鏈接

目前，業界流行的數據操做框架是 Mybatis，那 Druid 是什麼呢？ Druid 是 Java 的數據庫鏈接池組件。Druid 可以提供強大的監控和擴展功能。好比能夠監控 SQL ，在監控業務能夠查詢慢查詢 SQL 列表等。Druid 核心主要包括三部分： 1. DruidDriver 代理 Driver，可以提供基於 Filter－Chain 模式的插件體系。 2. DruidDataSource 高效可管理的數據庫鏈接池 3. SQLParser 當業務數據量達到了必定程度，DBA 須要合理配置數據庫資源。即配置主庫的機器高配置，把核心高頻的數據放在主庫上；把次要的數據放在低配置的從庫。開源節流嘛，把數據放在不一樣的數據庫裏，就須要經過不一樣的數據源進行操做數據。這裏咱們舉個 springboot-mutil-datasource 工程案例： user 用戶表在主庫 master 上，地址表 city 在從庫 slave上。java

1、數據庫準備

一、主庫mastermysql

CREATE DATABASE master;

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '用戶編號',
  `user_name` varchar(25) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '用戶名稱',
  `description` varchar(25) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '描述',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

INSERT user VALUES (1 ,'程序員','他有一個小網站 tom.com.cn');

二、從庫slave程序員

CREATE DATABASE slave;

DROP TABLE IF EXISTS `city`;
CREATE TABLE `city`  (
  `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '城市編號',
  `province_id` int(10) UNSIGNED NOT NULL COMMENT '省份編號',
  `city_name` varchar(25) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '城市名稱',
  `description` varchar(25) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '描述',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

INSERT city VALUES (1 ,1,'北京市','tom的家在北京。');

2、工程代碼配置詳解

一、項目總體結構web

com.carry.springboot.config.ds 包下包含了多數據源的配置，一樣能夠有第三個數據源，按照前幾個複製便可 resources/mapper 下面有兩個模塊，分別是 Mybatis 不一樣數據源須要掃描的 mapper xml 目錄spring

二、pom.xml依賴sql

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 3  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 4     <modelVersion>4.0.0</modelVersion>
 5 
 6     <groupId>com.carry.elk</groupId>
 7     <artifactId>springboot-mutil-datasource</artifactId>
 8     <version>0.0.1-SNAPSHOT</version>
 9     <packaging>jar</packaging>
10 
11     <name>springboot-mutil-datasource</name>
12     <description>Demo project for Spring Boot</description>
13 
14     <parent>
15         <groupId>org.springframework.boot</groupId>
16         <artifactId>spring-boot-starter-parent</artifactId>
17         <version>2.0.4.RELEASE</version>
18         <relativePath/> <!-- lookup parent from repository -->
19     </parent>
20 
21     <properties>
22         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24         <java.version>1.8</java.version>
25         <druid>1.0.31</druid>
26     </properties>
27 
28     <dependencies>
29         <dependency>
30             <groupId>org.springframework.boot</groupId>
31             <artifactId>spring-boot-starter-web</artifactId>
32         </dependency>
33         <dependency>
34             <groupId>org.mybatis.spring.boot</groupId>
35             <artifactId>mybatis-spring-boot-starter</artifactId>
36             <version>1.3.2</version>
37         </dependency>
38         <!-- Druid 數據鏈接池依賴 -->
39         <dependency>
40             <groupId>com.alibaba</groupId>
41             <artifactId>druid</artifactId>
42             <version>${druid}</version>
43         </dependency>
44 
45         <dependency>
46             <groupId>org.springframework.boot</groupId>
47             <artifactId>spring-boot-devtools</artifactId>
48             <scope>runtime</scope>
49         </dependency>
50         <dependency>
51             <groupId>mysql</groupId>
52             <artifactId>mysql-connector-java</artifactId>
53             <scope>runtime</scope>
54         </dependency>
55         <dependency>
56             <groupId>org.springframework.boot</groupId>
57             <artifactId>spring-boot-starter-test</artifactId>
58             <scope>test</scope>
59         </dependency>
60     </dependencies>
61 
62     <build>
63         <plugins>
64             <plugin>
65                 <groupId>org.springframework.boot</groupId>
66                 <artifactId>spring-boot-maven-plugin</artifactId>
67             </plugin>
68         </plugins>
69     </build>
70 
71 
72 </project>

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三、application.properties 配置兩個數據源配置數據庫

## master 數據源配置
master.datasource.url=jdbc:mysql://localhost:3306/master?useUnicode=true&characterEncoding=utf8
master.datasource.username=root
master.datasource.password=123456
master.datasource.driverClassName=com.mysql.jdbc.Driver

## slave 數據源配置
slave.datasource.url=jdbc:mysql://localhost:3306/slave?useUnicode=true&characterEncoding=utf8
slave.datasource.username=root
slave.datasource.password=123456
slave.datasource.driverClassName=com.mysql.jdbc.Driver

#熱部署
spring.devtools.restart.enabled=true

四、主數據源MasterDataSourceConfig 配置apache

 1 package com.carry.springboot.config.ds;  2 
 3 import javax.sql.DataSource;  4 
 5 import org.apache.ibatis.session.SqlSessionFactory;  6 import org.mybatis.spring.SqlSessionFactoryBean;  7 import org.mybatis.spring.annotation.MapperScan;  8 import org.springframework.beans.factory.annotation.Qualifier;  9 import org.springframework.beans.factory.annotation.Value; 10 import org.springframework.context.annotation.Bean; 11 import org.springframework.context.annotation.Configuration; 12 import org.springframework.context.annotation.Primary; 13 import org.springframework.core.io.support.PathMatchingResourcePatternResolver; 14 import org.springframework.jdbc.datasource.DataSourceTransactionManager; 15 
16 import com.alibaba.druid.pool.DruidDataSource; 17 
18 @Configuration 19 // 掃描 Mapper 接口並容器管理
20 @MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory") 21 public class MasterDataSourceConfig { 22 
23     // 精確到 master 目錄，以便跟其餘數據源隔離
24     static final String PACKAGE = "com.carry.springboot.dao.master"; 25     static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml"; 26 
27     @Value("${master.datasource.url}") 28     private String url; 29 
30     @Value("${master.datasource.username}") 31     private String user; 32 
33     @Value("${master.datasource.password}") 34     private String password; 35 
36     @Value("${master.datasource.driverClassName}") 37     private String driverClass; 38 
39     @Bean(name = "masterDataSource") 40  @Primary 41     public DataSource masterDataSource() { 42         DruidDataSource dataSource = new DruidDataSource(); 43  dataSource.setDriverClassName(driverClass); 44  dataSource.setUrl(url); 45  dataSource.setUsername(user); 46  dataSource.setPassword(password); 47         return dataSource; 48  } 49 
50     @Bean(name = "masterTransactionManager") 51  @Primary 52     public DataSourceTransactionManager masterTransactionManager() { 53         return new DataSourceTransactionManager(masterDataSource()); 54  } 55 
56     @Bean(name = "masterSqlSessionFactory") 57  @Primary 58     public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource) 59             throws Exception { 60         final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean(); 61  sessionFactory.setDataSource(masterDataSource); 62  sessionFactory.setMapperLocations( 63                 new PathMatchingResourcePatternResolver().getResources(MasterDataSourceConfig.MAPPER_LOCATION)); 64         return sessionFactory.getObject(); 65  } 66 }

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五、從數據源SlaveDataSourceConfig配置api

 1 package com.carry.springboot.config.ds;  2 
 3 import javax.sql.DataSource;  4 
 5 import org.apache.ibatis.session.SqlSessionFactory;  6 import org.mybatis.spring.SqlSessionFactoryBean;  7 import org.mybatis.spring.annotation.MapperScan;  8 import org.springframework.beans.factory.annotation.Qualifier;  9 import org.springframework.beans.factory.annotation.Value; 10 import org.springframework.context.annotation.Bean; 11 import org.springframework.context.annotation.Configuration; 12 import org.springframework.core.io.support.PathMatchingResourcePatternResolver; 13 import org.springframework.jdbc.datasource.DataSourceTransactionManager; 14 
15 import com.alibaba.druid.pool.DruidDataSource; 16 
17 @Configuration 18 // 掃描 Mapper 接口並容器管理
19 @MapperScan(basePackages = SlaveDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "slaveSqlSessionFactory") 20 public class SlaveDataSourceConfig { 21 
22     // 精確到 slave 目錄，以便跟其餘數據源隔離
23     static final String PACKAGE = "com.carry.springboot.dao.slave"; 24     static final String MAPPER_LOCATION = "classpath:mapper/slave/*.xml"; 25 
26     @Value("${slave.datasource.url}") 27     private String url; 28 
29     @Value("${slave.datasource.username}") 30     private String user; 31 
32     @Value("${slave.datasource.password}") 33     private String password; 34 
35     @Value("${slave.datasource.driverClassName}") 36     private String driverClass; 37 
38     @Bean(name = "slaveDataSource") 39     public DataSource slaveDataSource() { 40         DruidDataSource dataSource = new DruidDataSource(); 41  dataSource.setDriverClassName(driverClass); 42  dataSource.setUrl(url); 43  dataSource.setUsername(user); 44  dataSource.setPassword(password); 45         return dataSource; 46  } 47 
48     @Bean(name = "slaveTransactionManager") 49     public DataSourceTransactionManager slaveTransactionManager() { 50         return new DataSourceTransactionManager(slaveDataSource()); 51  } 52 
53     @Bean(name = "slaveSqlSessionFactory") 54     public SqlSessionFactory slaveSqlSessionFactory(@Qualifier("slaveDataSource") DataSource slaveDataSource) 55             throws Exception { 56         final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean(); 57  sessionFactory.setDataSource(slaveDataSource); 58  sessionFactory.setMapperLocations( 59                 new PathMatchingResourcePatternResolver().getResources(SlaveDataSourceConfig.MAPPER_LOCATION)); 60         return sessionFactory.getObject(); 61  } 62 }

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六、業務層代碼瀏覽器

 1 package com.carry.springboot.service.impl;  2 
 3 import org.springframework.beans.factory.annotation.Autowired;  4 import org.springframework.stereotype.Service;  5 
 6 import com.carry.springboot.dao.master.UserDao;  7 import com.carry.springboot.dao.slave.CityDao;  8 import com.carry.springboot.domain.City;  9 import com.carry.springboot.domain.User; 10 import com.carry.springboot.service.UserService; 11 
12 @Service 13 public class UserServiceImpl implements UserService { 14 
15  @Autowired 16     private UserDao userDao; // 主數據源
17 
18  @Autowired 19     private CityDao cityDao; // 從數據源
20 
21  @Override 22     public User findByName(String userName) { 23         User user = userDao.findByName(userName); 24         City city = cityDao.findByName("北京市"); 25  user.setCity(city); 26         return user; 27  } 28 
29 }