java.sql.SQLException: Connection is closed 异常通常表示在尝试使用数据库连接时,该连接已经被关闭。针对这个问题,我们可以从以下几个方面进行排查和解决: 1. 确认异常出现的上下文环境 首先,需要确认这个异常是在什么场景下出现的。例如,是在执行查询、更新操作,还是在连接初始化时就已经出现。这有助于我们定位问题...
原因:是因为 Java 连接 MySQL 没有收到任何数据包,也就是说连接失败。 解决方法:打开 Windows 服务程序,找到 mysql 进程,重启一下就可以了。
代码示例 importjava.sql.*;publicclassCheckConnection{publicstaticvoidmain(String[]args){Stringurl="jdbc:mysql://localhost:3306/mydatabase";Stringusername="root";Stringpassword="password";try{// 创建数据库连接Connectionconnection=DriverManager.getConnection(url,username,password);// 判断连接状态if(connect...
经验证通过调整应用端druid timeBetweenEvictionRunsMillis=300000 或修改服务器 max_idle_time=20,都可以解决。 另外,联想到之前也遇到过MySQL环境偶发的 Cause: java.sql.SQLException: Connection is closed 问题,是否也是相同的原因导致呢。 参考资料: https://blog.51cto.com/u_16112859/6277609...
is executed, the switch to the new database will not happen until the end of the current request. Only in a next request the database switch becomes effective.- The Connection String must connect to a database with the same type (e.g. Oracle, SQL Server, MySQL) as the one...
publicclassMySQLUtil{privatestaticfinalStringURL="jdbc:mysql://localhost:3306/mydatabase";privatestaticfinalStringUSERNAME="root";privatestaticfinalStringPASSWORD="password";privatestaticConnectionconnection=null;publicstaticConnectiongetConnection(){try{if(connection==null||connection.isClosed()){connection=Driv...
连接数据库的用户，只有查询权限 1、换个有所需权限的用户。2、给用户添加所需权限。
at org.gjt.mm.mysql.Connection.isClosed(Connection.java) at deployadmin.DBConnectionManager$DBConnectionPool.getConnection(DBConn ectionManager.java:296) at deployadmin.DBConnectionManager.getConnection(DBConnectionManager.jav a:77) at deployadmin.DeployDataBaseLayer.getProductNames(DeployDataBaseLayer.j ...
//1.getConnection()方法,连接MySQL数据库!! con = DriverManager.getConnection(url,user,password); if(!con.isClosed()) System.out.println("Succeeded connecting to the Database!"); //2.创建statement类对象,用来执行SQL语句!! Statement statement = con.createStatement(); ...
(Loader.java:1909) Caused by: java.sql.SQLException: Connection is closed at com.zaxxer.hikari.pool.ProxyConnection$ClosedConnection$1.invoke(ProxyConnection.java:469) at com.sun.proxy.$Proxy66.prepareStatement(Unknown Source) at com.zaxxer.hikari.pool.ProxyConnection.prepareStatement(ProxyConnection....