如何配置c3p0 eclipse

问题遇到的现象和发生背景

未能配置正确

问题相关代码，请勿粘贴截图

public class C3P0Demo1 {

public static void main(String[] args) throws SQLException {
    
1.创建数据库连接池对象
    DataSource ds=new ComboPooledDataSource();
2.获取连接对象
    Connection conn = ds.getConnection();

3.打印操作，判断对错
System.out.println(conn);

运行结果及报错内容

警告: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@4d6f1626 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.lang.NullPointerException: Cannot invoke "String.startsWith(String)" because "url" is null

我的解答思路和尝试过的方法

按照B站视频 需要几个jra包还有xml

我想要达到的结果

能够有输出语句

NullPointerException: Cannot invoke "String.startsWith(String)" because "url" is null
url为空，url配置看下。

1. 创建数据库连接池对象要设置jdbc链接信息

dataSource = new ComboPooledDataSource();
dataSource.setUser("root");
dataSource.setPassword("123456");
dataSource.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8");
dataSource.setDriverClass("com.mysql.jdbc.Driver");