jdbc连接sqlserver出现错误

写了个测试程序 1分钟查询一次sqlserver库 然后把结果写出来。
程序运行了3天了 今天出现了一个错误。
希望大家帮忙看看是什么问题。
Pl2 是机器名 系统为 linux
Mar 10, 2011 12:36:31 AM org.logicalcobwebs.proxool.Prototyper sweep
SEVERE: Prototype
com.microsoft.sqlserver.jdbc.SQLServerException: Pl2: Pl2
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.build70Logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:154)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)
2011-03-10 00:36:32 - 20975272
2011-03-10 00:36:33 - 20975273
2011-03-10 00:36:34 - 20975274
2011-03-10 00:36:35 - 20975275
2011-03-10 00:36:36 - 20975276
2011-03-10 00:36:37 - 20975277
2011-03-10 00:36:38 - 20975278
2011-03-10 00:36:39 - 20975279
com.microsoft.sqlserver.jdbc.SQLServerException: Pl2: Pl2
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.build70Logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:154)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.ConnectionPool.getConnection(ConnectionPool.java:211)
at org.logicalcobwebs.proxool.ProxoolDriver.connect(ProxoolDriver.java:89)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
at com.java.db.DriverClassProxool.getConnection(DriverClassProxool.java:144)
at com.java.db.OpenDBBasic.getConnection(OpenDBBasic.java:93)
at com.java.db.bean.db.DBGetInfo(db.java:20)
at j_BDQF.TCPClient.main(TCPClient.java:69)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.simontuffs.onejar.Boot.run(Boot.java:306)
at com.simontuffs.onejar.Boot.main(Boot.java:159)
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.simontuffs.onejar.Boot.run(Boot.java:306)
at com.simontuffs.onejar.Boot.main(Boot.java:159)
Caused by: java.lang.NullPointerException
at j_BDQF.TCPClient.main(TCPClient.java:73)
... 6 more
Mar 10, 2011 8:37:30 AM org.logicalcobwebs.proxool.Prototyper sweep
SEVERE: Prototype
com.microsoft.sqlserver.jdbc.SQLServerException: Pl2: Pl2
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.build70Logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:154)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)