SpringBoot 整合数据源的具体实践

<dependencies>
        <!-- spring boot 的核心starter -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

         <!-- Druid 连接池的 starter -->
        <!-- https://mvnrepository.com/artifact/com.alibaba/druid-spring-boot-starter -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.18</version>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <image>
                        <builder>paketobuildpacks/builder-jammy-base:latest</builder>
                    </image>
                </configuration>
            </plugin>
        </plugins>
    </build>

# 数据源连接池
spring:
  datasource:
    # 连接属性
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/psm
    username: root
    password: 123456
    # SpringBoot 内置的 hikari 连接池
    hikari:
      # 最小空闲连接
      minimum-idle: 5
      # 最大连接数
      maximum-pool-size: 20
      # 最大空闲时长
      idle-timeout: 900000
      # 连接的超时时间
      connection-timeout: 3000
      # 检查连接的有效性
      connection-test-query: select 1

@Slf4j
@SpringBootTest
class Ch04ApplicationTests {

    @Autowired
    private DataSource dataSource;


    @Test
    void contextLoads() throws SQLException {

        Connection connection = dataSource.getConnection();
        log.info("连接对象：" + connection);

    }
}

# 数据源连接池
spring:
  datasource:
    # 连接属性
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/psm
    username: root
    password: 123456

    # 使用 druid 连接池
    druid:
      # 最大连接数
      max-active: 100
      # 初始化连接数
      initial-size: 10
      # 最小连接池数
      min-idle: 10
      # 最大等待时间
      max-wait: 1000
      # 如果连接空闲时间大于等于（ min-evictable-idle-time-millis）
      # 的时长则关闭连接
      time-between-eviction-runs-millis: 60000
      # 连接保持空闲而不被驱逐出连接池
      min-evictable-idle-time-millis: 300000
      # 检查连接有效性
      validation-query: select 1
      # 是否缓存 preparedStatement (MySQL 建议关闭)
      pool-prepared-statements: false

@Slf4j
@SpringBootTest
class Ch04ApplicationTests {

    @Autowired
    private DataSource dataSource;

    /**
     * 注入 JDBC 的 Template，用于操作数据
     */
    @Autowired
    private JdbcTemplate template;

    @Test
    void contextLoads() throws SQLException {

        Connection connection = dataSource.getConnection();
        log.info("连接对象：" + connection);

    }

    @Test
    public void testJdbcTemplate(){
        List<Map<String, Object>> list = template.queryForList("select * from psm.city_info limit 0,10");
        list.forEach(map -> map.forEach((k,v) -> {
            log.info("键：" + k +"  " + "值：" + v);
        }) );
    }

}