工具：IntelliJ IDEA 2021.2.3、Microsoft SQL Server Management Studio 18
创建springboot项目
如图所示

因为没网的原因后面无法继续放图片了，也就是需要引用一些包，这边把pom.xml文件贴出来就可以了。

<?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>2.6.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.demo</groupId>
    <artifactId>Tool</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Tool</name>
    <description>Tool</description>
    <properties>
        <java.version>1.8</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.microsoft.sqlserver</groupId>
            <artifactId>mssql-jdbc</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.2</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.3.2</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.freemarker</groupId>
            <artifactId>freemarker</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>2.1.4</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>bootstrap</artifactId>
            <version>4.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.vaadin.external.google</groupId>
            <artifactId>android-json</artifactId>
            <version>0.0.20131108.vaadin1</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.demo</groupId>
            <artifactId>Tool</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
            <version>2.6.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-core-asl</artifactId>
            <version>1.9.12</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-mapper-asl</artifactId>
            <version>1.9.12</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>
        <!--保证配置文件能被扫描到-->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.yml</include>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.*</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>
</project>

配置多个数据库的连接，目前只放了两个数据库，需要更多数据库的话，照着自己写。(也可以加入mysql、oracle数据库混合连接）

mybatis.ims.mapper-locations=classpath:/mapper/ims/*.xml
mybatis-plus.configuration.map-underscore-to-camel-case=true
mybatis.client.mapper-locations=classpath:/mapper/client/*.xml
mybatis.type-aliases-package=com.demo.tool
mybatis-plus.global-config.db-config.id-type=auto
mybatis-plus.global-config.db-config.logic-not-delete-value=0
mybatis-plus.global-config.db-config.logic-delete-value=1

spring.datasource.ims.name=XXX1
spring.datasource.ims.url=jdbc:sqlserver://XXX;databaseName=XXX
spring.datasource.ims.username=XXX
spring.datasource.ims.password=XXX
spring.datasource.ims.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver

spring.datasource.ims.name=XXX2
spring.datasource.ims.url=jdbc:sqlserver://XXX;databaseName=XXX
spring.datasource.ims.username=XXX
spring.datasource.ims.password=XXX
spring.datasource.ims.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver

thymeleaf组件的配置文件

spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.check-template-location=true
spring.thymeleaf.cache=false
spring.thymeleaf.suffix=.html
spring.thymeleaf.mode=HTML
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.servlet.content-type=text/html

项目的基本配置

spring.application.name=spring-boot-config
server.port=8002
server.context-path=/
spring.mvc.static-path-pattern=/static/**
spring.autoconfigure.exclude=com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure