spring boot：Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured

Question

I am learning to use the spring boot framework to integrate MyBatis Plus and ShardingSphere to achieve MySQL master-slave read-write separation (one master and one slave)。

The master library is the 3306 port of my local localhost, and the slave library is in my locally installed Docker and uses the 3309 port mapping of the local localhost。

After testing, I can log in to the database on ports 3306 and 3309 locally.

• I'm writing my code in Visual Studio Code;master-slave MySQL 8.0+

But when I started the spring boot project I got this error message:

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class

Next I give the relevant configuration of my project:

application.yml:

server:
    port: 8080

spring:
    shardingsphere:
        datasource:
            names:
                master,slave
            master:
                type: com.alibaba.druid.pool.DruidDataSource
                driver-class-name: com.mysql.cj.jdbc.Driver
                url: jdbc:mysql://localhost:3306/rw?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
                username: root
                password: 5508769123
            slave:
                type: com.alibaba.druid.pool.DruidDataSource
                driver-class-name: com.mysql.cj.jdbc.Driver
                url: jdbc:mysql://localhost:3309/rw?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
                username: root
                password: 5508769123
        sharding:
        masterslave:
            load-balance-algorithm-type: round_robin
            name: dataSource
            master-data-source-name: master
            slave-data-source-names: slave
        props:
            sql:
                show: true 
    main:
        allow-bean-definition-overriding: true


mybatis-plus:
    configuration:
        map-underscore-to-camel-case: true
        log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    global-config:
        db-config:
            id-type: ASSIGN_ID

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 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>3.1.4</version>
        <relativePath/>
    </parent>
    <groupId>com.mercurows</groupId>
    <artifactId>rw_demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>rw_demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.30</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.22</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3</version>
            <!-- <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-jdbc</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-autoconfigure</artifactId>
                </exclusion>
                <exclusion>
                    <artifactId>spring-boot-autoconfigure</artifactId>
                    <groupId>org.springframework.boot</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>spring-boot-autoconfigure</artifactId>
                    <groupId>org.springframework.boot</groupId>
                </exclusion>
            </exclusions> -->
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>2.0.39</version>
        </dependency>

        <!-- 导入读写分离坐标 -->
        <dependency>
            <groupId>org.apache.shardingsphere</groupId>
            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
            <!-- <version>4.0.0-RC1</version> -->
            <version>4.1.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

My main:

package com.mercurows;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

// import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure;

import lombok.extern.slf4j.Slf4j;

@Slf4j
// @SpringBootApplication(exclude = DruidDataSourceAutoConfigure.class)
// @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class })
@SpringBootApplication
public class RwDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(RwDemoApplication.class, args);
        log.info("项目启动成功。。。");
    }
}

Thank you for taking the time to read my question.

I'm looking forward to any possible solutions.

I've tried:

1. @SpringBootApplication(exclude = DruidDataSourceAutoConfigure.class)
2. @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class })
3. Add exclusions in mybatis-plus-boot-starter：

       <dependency>
           <groupId>com.baomidou</groupId>
           <artifactId>mybatis-plus-boot-starter</artifactId>
           <version>3.5.3</version>
           <exclusions>
               <exclusion>
                   <groupId>org.springframework.boot</groupId>
                   <artifactId>spring-boot-starter-jdbc</artifactId>
               </exclusion>
               <exclusion>
                   <groupId>org.springframework.boot</groupId>
                   <artifactId>spring-boot-autoconfigure</artifactId>
               </exclusion>
               <exclusion>
                   <artifactId>spring-boot-autoconfigure</artifactId>
                   <groupId>org.springframework.boot</groupId>
               </exclusion>
               <exclusion>
                   <artifactId>spring-boot-autoconfigure</artifactId>
                   <groupId>org.springframework.boot</groupId>
               </exclusion>
           </exclusions>
       </dependency>
   

4. Version changes of some dependencies

expecting：Start the project normally and realize the read-write separation of the master-slave database.

Answer 1

The sharding-jdbc-spring-boot-starter in version 4.1.1 is over 3 years old, which was before Spring Boot 3 and the JakartaEE migration. So it seems to be incompatible.

Looking at the current documentation there is no more dedicated starter for Spring Boot and the whole architecture has also changed. It is no "just a Driver" which you need to configure.

In short, ditch the starter and configure the driver as mentioned in the documentation, which also has a dedicated Spring Boot 3 section on what to include/exclude to make it work.