[font color=#FF0000]点击进入后台后[/font]
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HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.lang.NullPointerException
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:523)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause

java.lang.NullPointerException
com.wgh.core.ConnDB.executeQuery(ConnDB.java:58)
com.wgh.dao.ManagerDAO.checkManager(ManagerDAO.java:15)
com.wgh.action.Manager.managerLogin(Manager.java:44)
com.wgh.action.Manager.execute(Manager.java:22)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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[font color=#FF0000]tomcat提示：[/font][/font]
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com.microsoft.sqlserver.jdbc.SQLServerException:到主机的TCP/IP连接失败。java.net.ConnectException:Connection timed out:connect 
                  ......
警告：DbConnectionManager.getConnectiong<>获得数据库连接失败。
警告：unhandled exception thrown:class java.lang.nullpointerexception
链接类型：com.microsoft.sqlserver.jdbc.SQLServerDriver
链接位置：jdbc:sqlerver://192.168.1.199:1433;DatabaseName=db_netExam
用户/密码/sa/[font color=#00FF00]111[/font]
三月...org.apache.struts.action.RequestProcessor processException
警告：Unhandled Exception thrown:class java.lang.NullPointerException
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我已经将[font color=#FF0000]connDB.properties[/font]改为：
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DB_CLASS_NAME=com.microsoft.sqlserver.jdbc.SQLServerDriver
DB_URL=jdbc:sqlserver://localhost:1433;DatabaseName=db_netExam
DB_USER=sa
DB_PWD=[font color=#00FF00]123[/font]
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     将[font color=#FF0000]ConnDB.java[/font]改为：
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      ......
private static String dbUrl = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=db_netExam";
private static String dbUser = "sa";
private static String dbPwd = "[font color=#00FF00]123[/font]";
      ......
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[font color=#FF0000]为什么还是出现错误？怎么处理？（我用的是SQLServer 2005。我的电脑上还装了一个MYSQL，和这个有关么？如果有关怎么处理？）谢谢老师。[/font]