【发布时间】：2022-07-07 11:34:06
【问题描述】：
重启 MySQL 后，WildFly 连接丢失。我们使用了 2 个版本的 MySQL，MySQL Ver 14.14 Distrib 5.6.51，用于使用 EditLine wrappe 的 Linux (x86_64) 和 MySQL Ver 8.0.28，用于 x86_64 上的 Linux（MySQL 社区服务器 - GPL）
我们尝试了 Wildfly wildfly-10.1.0.Final 和 wildfly-19.1.0.Final 的 2 个版本，我们使用了 JDBC，数据库连接器版本是 - 8.0.19
public static Connection getConnection() throws Exception {
LOG.debug("returning new connection");
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/xxx?allowPublicKeyRetrieval=true&useSSL=false", "xxxx", "xxxx");
return con;
}
重启MySQL服务器后如何自动重新连接，最好的方法是什么？
我们收到错误消息
1. 2022-04-08 16:09:36,614 ERROR [xxx.xxx.mysql.MysqlSentSMSDAo] (DefaultQuartzScheduler_Worker-9) No operations allowed after connection closed.: java.sql.SQLNonTransientConnectionException: No operations allowed after connection closed.
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:73)
at com.mysql.cj.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:1659)
at com.mysql.cj.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:1575)
at xxx.xxxx.loader.mysql.MysqlSentSMSDAo.selectReplyRecord(MysqlSentSMSDAo.java:85)
at xxx.xxx.loader.schedular.UpdateReplyReport.execute(UpdateReplyReport.java:109)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)
Caused by: com.mysql.cj.exceptions.ConnectionIsClosedException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.NativeSession.checkClosed(NativeSession.java:1171)
at com.mysql.cj.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:576)
at com.mysql.cj.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:1590)
... 5 more
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
2. The last packet successfully received from the server was 4,742 milliseconds ago. The last packet sent successfully to the server was 4,744 milliseconds ago.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeQuery(ClientPreparedStatement.java:1003)
at xxx.xxx.loader.mysql.MysqlSentSMSDAo.getListOfSQLSentSMSEntities(MysqlSentSMSDAo.java:39)
at xxx.xxx.loader.schedular.UpdateBulkReceipts.execute(UpdateBulkReceipts.java:59)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
【问题讨论】：
-
这看起来像是 20 多年前的代码。 Wildfly 有一个内置的连接池机制，其中一部分是在连接发出之前验证连接的能力。您是否收到任何关于该问题的异常或日志？
-
@stdunbar，我现在包含了错误消息，你能告诉我吗
-
这表明连接已经关闭。您的代码非常简单，即使连接不再有效，您也必须保持连接。您可以在使用连接之前致电
connection.isClosed()。但是，再一次，你这样做是困难的——使用内置的连接池。您不能重复使用已关闭的连接。你必须买一个新的。
标签： java mysql jboss ejb wildfly