java项目连接jdbc报错:com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server 原因:相关jar包版本太低 解决方法:下载最新版的mysql-connector-java即可…

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections" 原因:因为你的MySQL安装目录下的my.ini中设定的并发连接数太少或者系统繁忙导致连接数被占满 解决方式: 打开MYSQL安装目录打开MY.INI找到max_…

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unk…

前段时间,接手一个项目使用的是原始的jdbc作为数据库的访问,发布到服务器上在运行了一段时间之后总是会出现无法访问的情况,登录到服务器,查看tomcat日志发现总是报如下的错误. Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too man…

报错: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections" at sun.reflect.GeneratedConstructorAccessor16.newInstance(Unknown Source) at…

在运行"maven build"-->"tomcat:run"之后,报如下错误: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)…

ERROR - No operations allowed after connection closed. 2011-12-07 11:36:09 - ERROR - query failed org.hibernate.exception.JDBCConnectionException: could not execute query at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)…

折腾了好久,后来发现是版本问题,驱动和数据库不匹配导致. 原来用的是5.1.37的驱动.数据库是mysql5.7,可以连接成功. 就在我把数据库换成了8.0之后,所有的买点啥都报标题里的错误了.   换成了下边这个驱动就OK了.瞬间心情好了有没有!这个坑.实在是深啊!   有需要的朋友自行下载吧.我在mysql官网没找到????然后在maven里弄出来的.————————————————版权声明:本文为CSDN博主「勇勇米」的原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处…

-- 查询mysql 数据库链接空闲时间持有最大空闲时间,单位为秒 SHOW VARIABLES WHERE VAriable_name = 'interactive_timeout'; -- 会出现wait_timeout与该参数意思相近,修改时,一起修改 SHOW VARIABLES WHERE VAriable_name = '%timeout'; -- 解决问题 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Commun…

现象:客户端连接服务器端mysql是没问题的,所有都木有问题,应用程序配置也没问题,但是连接就抛异常: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets f…