Jam*_*mes 18 java postgresql io
我正在测试一些处理网站注册的代码.java代码如下(摘录):
if (request.getParameter("method").equals("checkEmail")){
String email= request.getParameter("email");
ResultSet rs =null;
PreparedStatement ps = db.prepareStatement(query);
ps.setString(1, email);
rs = ps.executeQuery();
if(rs.next()){
//email already present in Db
} else {
//proceed with registration.....
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大多数情况下,该过程执行没有任何问题,但我遇到了一个间歇性问题,因为它与数据库的连接正在关闭.每次失败时,它都会在同一点失败 - 运行上面准备好的语句(检查提交的电子邮件是否已经显然在数据库中).
Postgres的版本是8.1.23
任何帮助或建议表示赞赏.Stacktrace如下(编辑:有时Stacktrace说由Stream Closed导致,有时Socket Closed如下):
13:53:00,973 ERROR Registration:334 - org.postgresql.util.PSQLException: An I/O error occured while sending to the backend.
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:283)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:479
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:367)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:271)
at Registration.doPost(Registration.java:113)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:567)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:769)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:698)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:891)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.net.SocketException: Socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:135)
at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:104)
at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:73)
at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:259)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1620)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
... 22 more
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我怀疑您的应用程序和数据库位于不同的计算机上,并且两者之间存在(状态)防火墙。我的猜测是,防火墙在打开一定时间后可能会断开连接,可能没有流量。在向您发送断开的连接之前,连接池将无法检测到该错误。
唯一令我怀疑的是它总是在代码中的同一位置发生,但是如果这是新会话中的第一个数据库查询(或类似的东西),那不是不可能的,它可能总是出现在同一位置。