java - com.mysql.cj.jdbc.exceptions.CommunicationsException：通信链路故障，由读取超时引起

Question

使用 java swing 开发的销售点系统不时抛出以下异常。它不会每次都发生。我们在这里发现了一个类似的问题：Mysql Database records missing but sure it is inserted and log in local

com.mysql.cj.jdbc.exceptions.CommunicationsException：通信链路故障

由读取超时引起

我浏览了其他问题和答案，但我找不到适合我遇到的确切问题的答案。特别是“com.mysql.cj.jdbc.exceptions.CommunicationsException: 读取超时导致的通信链路故障”

为什么会出现这个异常？

这是 POS 系统在控制台中抛出的确切异常

    Sep 07, 2018 7:15:05 AM persistanceOperations.TransactionOperations view
SEVERE: null
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 5,402,907 milliseconds ago.  The last packet sent successfully to the server was 5,402,909 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:975)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeQuery(ClientPreparedStatement.java:1025)
        at persistanceOperations.TransactionOperations.view(TransactionOperations.java:146)
        at ui.Selling.loadLastestSales(Selling.java:4647)
        at ui.Selling.<init>(Selling.java:239)
        at ui.Operation.sellingActionPerformed(Operation.java:355)
        at ui.Operation.access$800(Operation.java:36)
        at ui.Operation$9.actionPerformed(Operation.java:245)
        at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
        at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
        at java.awt.Component.processMouseEvent(Unknown Source)
        at javax.swing.JComponent.processMouseEvent(Unknown Source)
        at java.awt.Component.processEvent(Unknown Source)
        at java.awt.Container.processEvent(Unknown Source)
        at java.awt.Component.dispatchEventImpl(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Window.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
        at java.awt.EventQueue.access$500(Unknown Source)
        at java.awt.EventQueue$3.run(Unknown Source)
        at java.awt.EventQueue$3.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
        at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
        at java.awt.EventQueue$4.run(Unknown Source)
        at java.awt.EventQueue$4.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet successfully received from the server was 5,402,907 milliseconds ago.  The last packet sent successfully to the server was 5,402,909 milliseconds ago.
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
        at java.lang.reflect.Constructor.newInstance(Unknown Source)
        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.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
        at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:556)
        at com.mysql.cj.protocol.a.NativeProtocol.checkErrorMessage(NativeProtocol.java:726)
        at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:665)
        at com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket(NativeProtocol.java:980)
        at com.mysql.cj.NativeSession.execSQL(NativeSession.java:1185)
        at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:952)
        ... 43 more
Caused by: java.net.SocketTimeoutException: Read timed out
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.socketRead(Unknown Source)
        at java.net.SocketInputStream.read(Unknown Source)
        at java.net.SocketInputStream.read(Unknown Source)
        at com.mysql.cj.protocol.ReadAheadInputStream.fill(ReadAheadInputStream.java:107)
        at com.mysql.cj.protocol.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:150)
        at com.mysql.cj.protocol.ReadAheadInputStream.read(ReadAheadInputStream.java:180)
        at java.io.FilterInputStream.read(Unknown Source)
        at com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:64)
        at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:63)
        at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:45)
        at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:52)
        at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:41)
        at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:54)
        at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:44)
        at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:550)
        ... 48 more

标签： javamysql