jdbc直连问题
本人用微软的三个直连包连SQLServer2000,将包导入整个工程,在连接时却发生不知什么异常，特寻求永中高手帮助？？
连接代码：
public static final String USER_NAME = "sa";
public static final String USER_PASSWORD = "";
public static final String DRIVER_COMMAND = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
public static final String CONNECTION_COMMAND = "jdbc:microsoft:sqlserver://yanchen:1433;DataBaseName=ShanXun_SZ";
Class.forName(Constant.DRIVER_COMMAND).newInstance();
con = DriverManager.getConnection(Constant.CONNECTION_COMMAND,
Constant.USER_NAME,
Constant.USER_PASSWORD);
异常代码：
java.sql.SQLException: [Microsoft][SQLServer JDBC Driver]Error establishing socket.
at com.microsoft.jdbc.base.BaseDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:525)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at net.shanxun.dao.DataSource.getConnection(DataSource.java:34)
at net.shanxun.dao.model.EmployeeManager.checkInvalidUser(EmployeeManager.java:37)
at net.shanxun.control.EmployeeManagerServlet.doGet(EmployeeManagerServlet.java:28)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at net.shanxun.control.EncodingFilter.doFilter(EncodingFilter.java:21)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)
