我写的测试SQL server 2005连接的程序，在命令行下编译运行均通过，但是JCreator编译通过，运行却出错，谁知道什么原因？

Question

 程序如下：import java.sql.*; 
public class test {
public static void main(String[] srg) {
   String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";   //锟斤拷锟斤拷JDBC锟斤拷
   String dbURL = "jdbc:sqlserver://localhost:1433; DatabaseName=WebMail";   //l锟接凤拷锟斤拷锟斤拷锟斤拷锟捷匡拷test
   String userName = "sa";   //默锟斤拷锟矫伙拷锟斤拷
   String userPwd = "452";   //锟斤拷锟斤拷
   Connection dbConn;   try {
   Class.forName(driverName);
   dbConn = DriverManager.getConnection(dbURL, userName, userPwd);
   System.out.println("Connection Successful!");   //锟斤拷锟絣锟接成癸拷 锟斤拷锟斤拷台锟斤拷锟紺onnection Successful!
   } catch (Exception e) {
   e.printStackTrace();
   }
}
} 
我在命令行下编译运行均通过，成功显示了：Connection Successful!但是，我用JCreator 直接打开test.java文件，编译通过，运行出现错误： java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:169)
        at test.main(test.java:11)
Press any key to continue...
 请问是什么原因呢？？要怎么解决？

Answer 1

找不到  com.microsoft.sqlserver.jdbc.SQLServerDriver检查环境变量

Answer 2

 我的环境变量：
classpath: .;C:\Program Files\sqljdbc_1.1\chs\sqljdbc.jar;%JAVA_HOME%\lib;%JAVA_HOME%\lib\tools.jar;C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\MyApp\ 配置的有问题吗？ 如果有问题，那在命令行下怎么能运行呢？

Answer 3

 还有： 我在MyEclipse里部署之后，在地址栏里输入：http://localhost:8081/succ/reg.jsp 结果出错，console信息如下： 信息: Undeploying context [/succ]
java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.aa.bean.Conn.<init>(Conn.java:13)
at org.apache.jsp.reg_jsp._jspService(reg_jsp.java:97)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:384)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
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:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
at java.lang.Thread.run(Thread.java:662)
No suitable driver found for jdbc:sqlserver://localhost:1433; DatabaseName=WebMail2011-2-24 11:54:29 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.reg_jsp._jspService(reg_jsp.java:181)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:384)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
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:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
at java.lang.Thread.run(Thread.java:662)
  究竟是什么问题呀？ 

Answer 4

把驱动放到CLASSPATH目录或WEB工程的LIB目录下如果还有错，检查是否是此错误
http://yuanyuan7891.javaeye.com/blog/633910