【Java开源代码栏目提醒】:文章导读:在新的一年中,各位网友都进入紧张的学习或是工作阶段。网学会员整理了Java开源代码-CommunicationsException.java的相关内容供大家参考,祝大家在新的一年里工作和学习顺利!
/*
Copyright (C) 2002-2004 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of version 2 of the GNU General Public License as
published by the Free Software Foundation.
There are special exceptions to the terms and conditions of the GPL
as it is applied to this software. View the full text of the
exception in file EXCEPTIONS-CONNECTOR-J in the directory of this
software distribution.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.mysql.jdbc;
import java.net.BindException;
import java.sql.SQLException;
/**
* An exception to represent communications errors with the database.
*
* Attempts to provide 'friendler' error messages to end-users, including last
* time a packet was sent to the database, what the client-timeout is set to,
* and whether the idle time has been exceeded.
*
* @author Mark Matthews
*
* @version $Id: CommunicationsException.java,v 1.1.2.1 2005/05/13 18:58:37
* mmatthews Exp $
*/
public class CommunicationsException extends SQLException {
private static final long DEFAULT_WAIT_TIMEOUT_SECONDS = 28800;
private static final int DUE_TO_TIMEOUT_FALSE = 0;
private static final int DUE_TO_TIMEOUT_MAYBE = 2;
private static final int DUE_TO_TIMEOUT_TRUE = 1;
private String exceptionMessage;
public CommunicationsException(Connection conn, long lastPacketSentTimeMs,
Exception underlyingException) {
long serverTimeoutSeconds = 0;
boolean isInteractiveClient = false;
if (conn != null) {
isInteractiveClient = conn.getInteractiveClient();
String serverTimeoutSecondsStr = null;
if (isInteractiveClient) {
serverTimeoutSecondsStr = conn
.getServerVariable("interactive_timeout"); //$NON-NLS-1$
} else {
serverTimeoutSecondsStr = conn
.getServerVariable("wait_timeout"); //$NON-NLS-1$
}
if (serverTimeoutSecondsStr != null) {
try {
serverTimeoutSeconds = Long
.parseLong(serverTimeoutSecondsStr);
} catch (NumberFormatException nfe) {
serverTimeoutSeconds = 0;
}
}
}
StringBuffer exceptionMessageBuf = new StringBuffer();
if (lastPacketSentTimeMs == 0) {
lastPacketSentTimeMs = System.currentTimeMillis();
}
long timeSinceLastPacket = (System.currentTimeMillis() - lastPacketSentTimeMs) / 1000;
int dueToTimeout = DUE_TO_TIMEOUT_FALSE;
StringBuffer timeoutMessageBuf = null;
if (serverTimeoutSeconds != 0) {
if (timeSinceLastPacket > serverTimeoutSeconds) {
dueToTimeout = DUE_TO_TIMEOUT_TRUE;
timeoutMessageBuf = new StringBuffer();
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.2")); //$NON-NLS-1$
if (!isInteractiveClient) {
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.3")); //$NON-NLS-1$
} else {
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.4")); //$NON-NLS-1$
}
}
} else if (timeSinceLastPacket > DEFAULT_WAIT_TIMEOUT_SECONDS) {
dueToTimeout = DUE_TO_TIMEOUT_MAYBE;
timeoutMessageBuf = new StringBuffer();
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.5")); //$NON-NLS-1$
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.6")); //$NON-NLS-1$
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.7")); //$NON-NLS-1$
timeoutMessageBuf.append(Messages
.getString("CommunicationsException.8")); //$NON-NLS-1$
}
if (dueToTimeout == DUE_TO_TIMEOUT_TRUE
|| dueToTimeout == DUE_TO_TIMEOUT_MAYBE) {
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.9")); //$NON-NLS-1$
exceptionMessageBuf.append(timeSinceLastPacket);
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.10")); //$NON-NLS-1$
if (timeoutMessageBuf != null) {
exceptionMessageBuf.append(timeoutMessageBuf);
}
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.11")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.12")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.13")); //$NON-NLS-1$
} else {
//
// Attempt to determine the reason for the underlying exception
// (we can only make a best-guess here)
//
if (underlyingException instanceof BindException) {
// too many client connections???
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.14")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.15")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.16")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.17")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.18")); //$NON-NLS-1$
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.19")); //$NON-NLS-1$
}
}
if (exceptionMessageBuf.length() == 0) {
// We haven't figured out a good reason, so copy it.
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.20")); //$NON-NLS-1$
if (underlyingException != null) {
exceptionMessageBuf.append(Messages
.getString("CommunicationsException.21")); //$NON-NLS-1$
exceptionMessageBuf.append(Util
.stackTraceToString(underlyingException));
}
if (conn != null && conn.getMaintainTimeStats() &&
!conn.getParanoid()) {
exceptionMessageBuf.append("\n\nLast packet sent to the server was ");
exceptionMessageBuf.append(System.currentTimeMillis() - lastPacketSentTimeMs);
exceptionMessageBuf.append(" ms ago.");
}
}
this.exceptionMessage = exceptionMessageBuf.toString();
}
/*
* (non-Javadoc)
*
* @see java.lang.Throwable#getMessage()
*/
public String getMessage() {
return this.exceptionMessage;
}
/*
* (non-Javadoc)
*
* @see java.sql.SQLException#getSQLState()
*/
public String getSQLState() {
return SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE;
}
}
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