SpringBoot入門之基於Druid配置Mybatis多數據源

阿新 • • 發佈：2018-07-23

this ssp hide llb 就是 delet exc .sql isp

上一篇了解了Druid進行配置連接池的監控和慢sql處理，這篇了解下使用基於基於Druid配置Mybatis多數據源。SpringBoot默認配置數據庫連接信息時只需設置url等屬性信息就可以了，SpringBoot就會基於約定根據配置信息實例化對象，但是一般大型的項目都是有多個子系統或者多個數據源組成，那怎麽使用SpringBoot進行Mybatis多數據源配置呢？

一、數據庫準備

我們這裏準備使用主從兩個數據庫來進行演示多數據源配置。一個主庫用來寫write，一個從庫用來讀read.至於兩個數據庫的數據同步問題這裏暫時不考慮。兩個數據庫只是數據庫名不一樣，主庫為mybatis1，從庫為mybatis,表結構是一樣的。

主庫(write):

CREATE DATABASE `mybatis1` /*!40100 DEFAULT CHARACTER SET utf8 */;
CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL,
  `age` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8;

從庫(read):

CREATE DATABASE 
 `mybatis` /*!40100 DEFAULT CHARACTER SET utf8 */;
CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL,
  `age` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8;

二、引入依賴

這裏主要引入mysql數據庫、mybatis架構、Druid相關的SpringBoot依賴。下面的是由於要使用jsp顯示內容所以也假如了jsp相關的依賴。

<?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>2.0.1.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>1.8</java.version>

    </properties>

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



        <!-- https://mvnrepository.com/artifact/org.thymeleaf/thymeleaf-spring5 
        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf-spring5</artifactId>
            <version>3.0.9.RELEASE</version>
        </dependency>
         -->

       <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>
    
        <dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>druid-spring-boot-starter</artifactId>
           <version>1.1.10</version>
        </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>

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三、創建Mapper

從這裏開始就比較坑了，為了寫這篇博客昨天搞到夜裏兩點中，Druid官方介紹的比較少，demo也不是與mybatis相結合，就倒置怎麽把mapper與數據源配置對照上也是問題，因為默認單數據源的話，配置下數據源信息以及Mapper就好，但是如果是多數據源那就要手動指定數據源在哪裏，怎麽和Mapper對照上。

這裏先創建兩個Mappe，一個是寫的一個是讀的。這裏要註意的地方是要加上@Mapper註解。

技術分享圖片

ReadUserMapper:

package com.example.read.mapper;
import java.util.List;
import com.example.model.User;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

@Mapper
public interface  ReadUserMapper {

    @Select("SELECT name FROM user")

    @Results({

        @Result(property = "Name", column = "name")

    })

    List<User> getAll();

    

    @Select("SELECT name FROM user WHERE id = #{id}")

    @Results({

        @Result(property = "Name", column = "name")

    })

    User getOne(int id);



    @Insert("INSERT INTO user(name,age) VALUES(#{name}, #{age})")

    void insert(User user);

    @Update("UPDATE user SET name=#{name},age=#{age} WHERE id =#{id}")

    void update(User user);

    @Delete("DELETE FROM user WHERE id =#{id}")

    void delete(int id);
}

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WriteUserMapper：

package com.example.write.mapper;
import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import com.example.model.*;

@Mapper
public interface  WriteUserMapper {

    @Select("SELECT name FROM user")

    @Results({

        @Result(property = "Name", column = "name")

    })

    List<User> getAll();

    @Select("SELECT name FROM user WHERE id = #{id}")

    @Results({

        @Result(property = "Name", column = "name")

    })

    User getOne(int id);

    @Insert("INSERT INTO user(name,age) VALUES(#{name}, #{age})")

    void insert(User user);


    @Update("UPDATE user SET name=#{name},age=#{age} WHERE id =#{id}")

    void update(User user);


    @Delete("DELETE FROM user WHERE id =#{id}")

    void delete(int id);
}

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四、配置數據源

如果使用SpringBoot默認配置類,可以直接在application.properties中配置就好了,它會自動掃描mapper類與數據源進行關聯，但是如果是多個數據源的話，那就需要進行手動配置。這裏分別創建了讀DataSourceReadConfig、寫DataSourceWriteConfig數據源配置類。

DataSourceWriteConfig:

package com.example.config;



import javax.sql.DataSource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
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 org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.stereotype.Component;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;

@Configuration
@MapperScan(basePackages = "com.example.write.mapper", sqlSessionTemplateRef  = "writeSqlSessionTemplate")
public class DataSourceWriteConfig {
    @Bean(name = "writeDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.write")
    @Qualifier("writeDataSource")
    @Primary
    public DataSource writeDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean(name = "writeSqlSessionFactory")
    @Primary
    public SqlSessionFactory writeSqlSessionFactory(@Qualifier("writeDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        return bean.getObject();
    }

    @Bean(name = "writeTransactionManager")
    @Primary
    public DataSourceTransactionManager writeTransactionManager(@Qualifier("writeDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "writeSqlSessionTemplate")
    @Primary
    public SqlSessionTemplate writeSqlSessionTemplate(@Qualifier("writeSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

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DataSourceReadConfig:

package com.example.config;



import javax.sql.DataSource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;

@Configuration
@MapperScan(basePackages = "com.example.read.mapper", sqlSessionTemplateRef  = "readSqlSessionTemplate")
public class DataSourceReadConfig {
    @Bean(name = "readDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.read")
    @Qualifier("readDataSource")
    public DataSource readDataSource() {
        return DruidDataSourceBuilder.create().build();
    }
 
    @Bean(name = "readSqlSessionFactory")
    
    public SqlSessionFactory readSqlSessionFactory(@Qualifier("readDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource((javax.sql.DataSource) dataSource);
        return bean.getObject();
    }

    @Bean(name = "readTransactionManager")
   
    public DataSourceTransactionManager readTransactionManager(@Qualifier("readDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "readSqlSessionTemplate")
    
    public SqlSessionTemplate readSqlSessionTemplate(@Qualifier("readSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

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這部分是遇到坑最多的地方，由於Druid官方github上並沒有具體參考的demo,看其他的博客又與gitgub介紹的有出入，比如獲取配置類中獲取DataSource方法中，其他我看使用的是DataSourceBuilder，但Druid GitHub上的是DruidDataSourceBuilder,不知道是不是版本的問題，如果使用DataSourceBuilder，配置多數據庫時不起作用。github上也有這句話:Spring Boot 2.X 版本不再支持配置繼承，多數據源的話每個數據源的所有配置都需要單獨配置，否則配置不會生效。還有就是DataSource引入的包名，我開始引入的並不是import javax.sql.DataSource;這個也是一個坑。

五、Druid多數據源配置

這裏也遇到了坑，由於在配置數據源類中並未使用DruidDataSourceBuilder，而是使用的DataSourceBuilder，這就導致下面配置的沒用，而且在設置數據庫url還報錯，需要使用jdbc-url.

spring.mvc.view.prefix=/view/

spring.mvc.view.suffix=.jsp
mybatis.type-aliases-package=com.example.model
#mybatis.config-location=classpath:mybatis/mybatis-config.xml
#mybatis.mapper-locations=classpath:mybatis/mapper/*.xml


spring.datasource.druid.read.web-stat-filter.enabled=true
spring.datasource.druid.read.web-stat-filter.url-pattern=/*
spring.datasource.druid.read.web-stat-filter.exclusions=*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*
spring.datasource.druid.read.web-stat-filter.session-stat-enable=true
spring.datasource.druid.read.web-stat-filter.session-stat-max-count=1000
spring.datasource.druid.read.stat-view-servlet.enabled= true
spring.datasource.druid.read.stat-view-servlet.url-pattern=/druid/*
spring.datasource.druid.read.stat-view-servlet.reset-enable=true
spring.datasource.druid.read.stat-view-servlet.login-username=druid
spring.datasource.druid.read.stat-view-servlet.login-password=123456
spring.datasource.druid.read.stat-view-servlet.allow=127.0.0.1
spring.datasource.druid.read.stat-view-servlet.deny=192.168.0.19
spring.datasource.druid.read.aop-patterns=com.example.read.mapper.*

spring.datasource.druid.read.url =jdbc:mysql://127.0.0.1:3306/mybatis?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.druid.read.username = root
spring.datasource.druid.read.password = 123456
spring.datasource.druid.read.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.druid.read.type=com.alibaba.druid.pool.DruidDataSource


spring.datasource.druid.write.max-active=20
spring.datasource.druid.write.initial-size=1
spring.datasource.druid.write.max-wait=60000
spring.datasource.druid.write.pool-prepared-statements=true
spring.datasource.druid.write.max-pool-prepared-statement-per-connection-size=20
spring.datasource.druid.write.connection-properties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
spring.datasource.druid.write.min-idle=1
spring.datasource.druid.write.time-between-eviction-runs-millis=60000
spring.datasource.druid.write.min-evictable-idle-time-millis=300000
spring.datasource.druid.write.validation-query=select 1 from dual
spring.datasource.druid.write.test-while-idle=true
spring.datasource.druid.write.test-on-borrow=true
spring.datasource.druid.write.test-on-return=true

spring.datasource.druid.write.web-stat-filter.enabled=true
spring.datasource.druid.write.web-stat-filter.url-pattern=/*
spring.datasource.druid.write.web-stat-filter.exclusions=*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*
spring.datasource.druid.write.web-stat-filter.session-stat-enable=true
spring.datasource.druid.write.web-stat-filter.session-stat-max-count=1000
spring.datasource.druid.write.stat-view-servlet.enabled= true
spring.datasource.druid.write.stat-view-servlet.url-pattern=/druid/*
spring.datasource.druid.write.stat-view-servlet.reset-enable=true
spring.datasource.druid.write.stat-view-servlet.login-username=druid
spring.datasource.druid.write.stat-view-servlet.login-password=123456
spring.datasource.druid.write.stat-view-servlet.allow=127.0.0.1
spring.datasource.druid.write.stat-view-servlet.deny=192.168.0.19
spring.datasource.druid.write.url =jdbc:mysql://127.0.0.1:3306/mybatis1?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.druid.write.aop-patterns=com.example.write.mapper.*
spring.datasource.druid.write.username = root
spring.datasource.druid.write.password = 123456
spring.datasource.druid.write.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.druid.write.type=com.alibaba.druid.pool.DruidDataSource

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六、多數據源的使用

這裏並未設置Service層，而是直接在Controller中使用。在Controller中會裝配一個寫的mapper一個讀的mapper,分別進行查詢和新增操作。

package com.example.demo;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.example.model.User;

import com.example.read.mapper.ReadUserMapper;
import com.example.write.mapper.WriteUserMapper;

@Controller
@RequestMapping("/user")
public class UserController {
    
    @Autowired
    private WriteUserMapper userMapperWrite;
    
    @Autowired
    private ReadUserMapper userMapperRead;
    
    @RequestMapping(value = "/alluser.do",method = RequestMethod.GET)
    public String getallusers(Model model) {
       List<User> users=userMapperRead.getAll();
       model.addAttribute("users", users);
       return "userlist";
    }
    @RequestMapping(value = "/insert.do",method = RequestMethod.GET)
    public String adduser(Model model) {
       User user=new User();
       user.setName("cuiyw");
       user.setAge(27);    
       userMapperWrite.insert(user);
       List<User> users=userMapperWrite.getAll();
       model.addAttribute("users", users);
       return "userlist";
    }
}

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七、指定數據源配置文件位置

上面基本把配置信息都配置好了，但是如果這樣運行還是會報錯誤,它還是不能找到這個mapper,此時需要在main方法文件增加註解@ComponentScan(basePackages={"com.example.config","com.example.demo"})，讓它掃描配置文件的包，然後在配置文件的包裏面有配置@MapperScan來查找到mapper。

package com.example.demo;

import org.springframework.boot.SpringApplication;
//import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
//import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
//@EnableAutoConfiguration(exclude= {DataSourceAutoConfiguration.class})

@ComponentScan(basePackages={"com.example.config","com.example.demo"})
@SpringBootApplication
public class DemoApplication {

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

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Description:

Field userMapperWrite in com.example.demo.UserController required a bean of type ‘com.example.write.mapper.WriteUserMapper‘ that could not be found.

Action:
Consider defining a bean of type ‘com.example.write.mapper.WriteUserMapper‘ in your configuration.

八、其他問題

1.這裏還遇到404找不到路徑的錯誤，這裏還需要在@ComponentScan註解加上Controller對應的包，所以上面代碼有@ComponentScan(basePackages={"com.example.config","com.example.demo"})。

This application has no explicit mapping for /error, so you are seeing this as a fallback.
Sun Jul 22 23:58:27 CST 2018
There was an unexpected error (type=Not Found, status=404).
No message available

2.設置手動配置問題

由於開始使用的是DataSourceBuilder，但在application.properties還是使用spring.datasource.druid.read這種方法進行配置，並沒spring.datasource.url這樣配置，導致報下面的錯誤。因為使用的是DataSourceBuilder所以SpringBoot還是認為用的默認配置，所以就找spring.datasource.url，此時可以使用@EnableAutoConfiguration(exclude= {DataSourceAutoConfiguration.class})註解來設置手動註解。

技術分享圖片

九、測試

這裏還是分別輸入http://localhost:8080/user/alluser.do，http://localhost:8080/user/insert.do，然後查看兩個數據庫user表的數據是否有沒有改變，讀數據庫數據未變，寫數據庫數據增加。Druid的數據源監測也是有兩條數據源信息。

技術分享圖片

SpringBoot入門之基於Druid配置Mybatis多數據源

this ssp hide llb 就是 delet exc .sql isp 上一篇了解了Druid進行配置連接池的監控和慢sql處理，這篇了解下使用基於基於Druid配置Mybatis多數據源。SpringBoot默認配置數據庫連接信息時只需設置url等屬性信息就可以了

SpringBoot入門之基於Druid配置Mybatis多數據源

SpringBoot入門之基於Druid配置Mybatis多數據源

SpringBoot入門之基於Druid配置Mybatis多資料來源

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SpringBoot+Mybatis+ Druid+PageHelper 實現多數據源並分頁

springboot-mybatis多數據源以及踩坑之旅

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spring基於通用Dao的多數據源配置

第九章 springboot + mybatis + 多數據源（AOP實現）

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SpringBoot ( 七 ) ：springboot + mybatis 多數據源最簡解決方案

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SpringMVC mybatis 多數據源代碼生成器 SSM java redis shiro ehcache

JNDI數據源（在Tomcat下配置JNDI多數據源實例）

mybatis多數據源報錯

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springboot 2.1.3 + mybatis + druid配置多數據源

SpringBoot入門之簡單配置

SpringBoot入門之基於Druid配置Mybatis多數據源

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