import java.io.FileReader;
 java.sql.Connection;
 java.sql.ResultSet;
 java.sql.Statement;
 java.util.Properties;

 javax.sql.DataSource;

 org.apache.commons.dbcp.BasicDataSourceFactory;

public class DBCPTest {
    static void main(String[] args) throws Exception {
        //导入配置文件
        Properties prop=new Properties();
        prop.load(new FileReader("dbcp.properties"));
        获取数据源
        BasicDataSourceFactory factory= BasicDataSourceFactory();
        DataSource pool=factory.createDataSource(prop);
        
        Connection conn=pool.getConnection();
        获取传输器对象
        Statement statement=conn.createStatement();
        获取结果集对象
        ResultSet resultSet=statement.executeQuery("select * from user");
        遍历
        while(resultSet.next()){
            String username=resultSet.getString("username");
            System.out.println(username);
        }
        关闭资源
        resultSet.close();
        statement.close();
        conn.close();
        
    }
}

driverClassName=com.MysqL.jdbc.Driver
url=jdbc:MysqL:///java
username=root
password=root

 java.sql.Statement;

 com.mchange.v2.c3p0.ComboPooledDataSource;

使用C3P0
        ComboPooledDataSource pool= ComboPooledDataSource();
        Connection conn=        resultSet.close();
        statement.close();
        conn.close();
        
    }
}

<?xml version="1.0" encoding="utf-8"?>
<c3p0-config>
    default-config>
        property name="driverClass">com.MysqL.jdbc.Driver</property="jdbcUrl">jdbc:MysqL:///java="user">root="password">
>