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