When using the druid connection pool, Exception in thread "main" java.lang.NullPointerException is reported

八月 26, 2020 11:27:45 上午 com.alibaba.druid.pool.DruidDataSource info
信息: {
    
    dataSource-1} inited
Exception in thread "main" java.lang.NullPointerException
	at com.alibaba.druid.util.JdbcUtils.getDriverClassName(JdbcUtils.java:354)
	at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:577)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:915)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:911)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:98)
	at cn.itcast.utils.JDBCUtils.getConnection(JDBCUtils.java:50)
	at cn.itcast.datasource.druid.DruidDemo2.main(DruidDemo2.java:22)

Connection conn=null;
conn= JDBCUtils.getConnection();

This is 22 lines of code. It feels right. Other codes are common on the Internet. I tried step by step and finally found a problem with druid.properties. The configuration is attached:

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/db?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone =Asia/Shanghai
username=root
password=password
initialSize=10
maxActive=50
minIdle=5
maxWait=6000
connectionProperties=useUnicode=true;characterEncoding=utf8
defaultAutoCommit=true
defaultTransactionIsolation=REPEATABLE_READ
validationQuery:SELECT 1
testWhileIdle:true
testOnBorrow:false
testOnReturn:false