BEGIN NESTED EXCEPTION 问题，高手指教！

zhangzuwu 2007-11-22 12:27:11

这几天网页不时的出现下边的问题，这是怎么回事，高手指教！链接信息和错误信息如下：
Class.forName("org.gjt.mm.mysql.Driver").newInstance();
String url ="jdbc:mysql://"+server+":"+port+"/"+dbname+"?user="+user+"&password="+pass+"&useUnicode=true&characterEncoding=gbk";
conn= DriverManager.getConnection(url);

500 Servlet Exception
com.mysql.jdbc.CommunicationsException: Communications link failure due
to underlying exception:

** BEGIN NESTED EXCEPTION **

java.net.SocketException
MESSAGE: Connection reset

STACKTRACE:

java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:168)
at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1931)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2380)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2909)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1600)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1695)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3020)
at com.mysql.jdbc.Connection.setAutoCommit(Connection.java:4989)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3854)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2585)
at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:193)
at _jsp._content__jsp._jspService(_content__jsp.java:62)
at com.caucho.jsp.JavaPage.service(JavaPage.java:60)
at com.caucho.jsp.Page.pageservice(Page.java:570)
at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:175)
at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485)
at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350)
at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:926)
at _jsp._index__jsp._jspService(_index__jsp.java:33)
at com.caucho.jsp.JavaPage.service(JavaPage.java:60)
at com.caucho.jsp.Page.pageservice(Page.java:570)
at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:175)
at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:178)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
at com.caucho.server.hmux.HmuxRequest.handleRequest(HmuxRequest.java:419)
at com.caucho.server.port.TcpConnection.run(TcpConnection.java:389)
at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:507)
at com.caucho.util.ThreadPool.run(ThreadPool.java:433)
at java.lang.Thread.run(Thread.java:534)

** END NESTED EXCEPTION **

Last packet sent to the server was 40 ms ago.
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2592)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2909)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1600)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1695)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3020)
at com.mysql.jdbc.Connection.setAutoCommit(Connection.java:4989)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:3854)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2585)
at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:193)
at _jsp._content__jsp._jspService(content.jsp:36)
at com.caucho.jsp.JavaPage.service(JavaPage.java:60)
at com.caucho.jsp.Page.pageservice(Page.java:570)
at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:175)
at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485)
at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350)
at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:926)
at _jsp._index__jsp._jspService(index.jsp:4)
at com.caucho.jsp.JavaPage.service(JavaPage.java:60)
at com.caucho.jsp.Page.pageservice(Page.java:570)
at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:175)
at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:178)
at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
at com.caucho.server.hmux.HmuxRequest.handleRequest(HmuxRequest.java:419)
at com.caucho.server.port.TcpConnection.run(TcpConnection.java:389)
at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:507)
at com.caucho.util.ThreadPool.run(ThreadPool.java:433)
at java.lang.Thread.run(Thread.java:534)

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