项目结构如下

 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>2.6.7</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-jdbc</artifactId>
        </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>com.dm</groupId>
            <artifactId>dmJdbcDriver</artifactId>
            <version>1.7.18</version>
        </dependency>

        <dependency>
            <groupId>com.dm</groupId>
            <artifactId>DmDialect</artifactId>
            <version>5.0</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.6</version>
        </dependency>

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

 定义配置类加入Bean工厂

package com.example.demo.config;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

@Configuration
public class DataSourceConfig {

    @Value("${spring.datasource.url}")
    String url;

    @Value("${spring.datasource.username}")
    String username;

    @Value("${spring.datasource.password}")
    String password;

    @Bean
    public DruidDataSource getDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }

}

  实体类：

package com.example.demo.entity;

public class Test {

    private String time;
    private String data;

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

    public String getData() {
        return data;
    }

    public void setData(String data) {
        this.data = data;
    }
}

 Service

package com.example.demo.service;

import com.example.demo.entity.Test;

import java.sql.SQLException;
import java.util.List;

public interface TestService {
    List<Test> getAllData() throws SQLException;
}

 实现类：

package com.example.demo.impl;

import com.alibaba.druid.pool.DruidDataSource;
import com.example.demo.entity.Test;
import com.example.demo.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

@Service
public class TestServiceImpl implements TestService {

    @Autowired
    DruidDataSource druidDataSource;

    @Override
    public List<Test> getAllData() throws SQLException {
        List<Test> tests = new ArrayList<>();
        Connection conn = druidDataSource.getConnection();
        String sql = "select * from TEST ";
        PreparedStatement pstmt = conn.prepareStatement(sql);

        ResultSet rs = pstmt.executeQuery();
        Test test = null;

        while (rs.next()){
            //获取数据
            String time =
                    rs.getString("time");
            String data =
                    rs.getString("data");
            //封装Brand对象
            test = new Test();
            test.setTime(time);
            test.setData(data);

            tests.add(test);
        }
        conn.close();
        return tests;
    }
}

package com.example.demo;

import com.alibaba.druid.pool.DruidDataSource;
import com.example.demo.entity.Test;
import com.example.demo.service.TestService;
import org.omg.CORBA.ARG_IN;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import javax.swing.*;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

@SpringBootApplication
public class DemoApplication  implements CommandLineRunner {

    @Autowired
    TestService testService;

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

    }

    @Override
    public void run(String... args) throws Exception {

        List<Test> list = testService.getAllData();
        for (Test test : list) {
            System.out.println(test.getTime());
            System.out.println(test.getData());
        }

    }
}