springboot 集成dbcp连接池

Spring Boot 集成 DBCP 连接池需要进行以下步骤：

1. 添加 DBCP 的依赖

在 pom.xml 文件中添加以下依赖：

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-dbcp2</artifactId>
    <version>2.7.0</version>
</dependency>

2. 添加数据库配置

在 application.properties 或 application.yml 中添加数据库相关配置，如下所示：

# 数据库驱动
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
# 数据库连接地址
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=false
# 数据库用户名
spring.datasource.username=root
# 数据库密码
spring.datasource.password=123456

# 连接池参数
spring.datasource.initialSize=5
spring.datasource.minIdle=5
spring.datasource.maxIdle=20
spring.datasource.maxTotal=50
spring.datasource.maxWaitMillis=60000
spring.datasource.validationQuery=select 1 from dual
spring.datasource.testWhileIdle=true
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.numTestsPerEvictionRun=5
spring.datasource.testOnBorrow=true
spring.datasource.testOnReturn=false

3. 配置 DBCP 连接池

在 Spring Boot 应用启动类上添加 `@Configuration` 注解，并配置 DBCP 连接池，如下所示：

@Configuration
public class DbcpConfig {

    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;

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

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

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

    @Value("${spring.datasource.initialSize}")
    private int initialSize;

    @Value("${spring.datasource.minIdle}")
    private int minIdle;

    @Value("${spring.datasource.maxIdle}")
    private int maxIdle;

    @Value("${spring.datasource.maxTotal}")
    private int maxTotal;

    @Value("${spring.datasource.maxWaitMillis}")
    private long maxWaitMillis;

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

    @Value("${spring.datasource.testWhileIdle}")
    private boolean testWhileIdle;

    @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
    private long timeBetweenEvictionRunsMillis;

    @Value("${spring.datasource.numTestsPerEvictionRun}")
    private int numTestsPerEvictionRun;

    @Value("${spring.datasource.testOnBorrow}")
    private boolean testOnBorrow;

    @Value("${spring.datasource.testOnReturn}")
    private boolean testOnReturn;

    @Bean
    public DataSource dataSource() {
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setInitialSize(initialSize);
        dataSource.setMinIdle(minIdle);
        dataSource.setMaxIdle(maxIdle);
        dataSource.setMaxTotal(maxTotal);
        dataSource.setMaxWaitMillis(maxWaitMillis);
        dataSource.setValidationQuery(validationQuery);
        dataSource.setTestWhileIdle(testWhileIdle);
        dataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        dataSource.setNumTestsPerEvictionRun(numTestsPerEvictionRun);
        dataSource.setTestOnBorrow(testOnBorrow);
        dataSource.setTestOnReturn(testOnReturn);
        return dataSource;
    }
}

4. 使用 DataSource

在需要使用数据库连接的地方，可以通过 `@Autowired` 注入 DataSource，然后获取 Connection，如下所示：

@Autowired
private DataSource dataSource;

public void executeSql(String sql) throws SQLException {
    try (Connection conn = dataSource.getConnection();
         Statement stmt = conn.createStatement()) {
        stmt.execute(sql);
    }
}