jsp中JDBC连接时出现SQLException异常

 我想建立一个新的数据库，所以运行了下面这段程序时：
           
  <body> <font size=2>
     <%   
          Connection conn=null;
          Statement stmt=null;
          PreparedStatement st=null;
          String sql=null;
          int ret;
            
          
          try{
             Class.forName("com.mysql.jdbc.Driver");
             String strCon="jdbc:mysql://localhost:3306/";
             conn= DriverManager.getConnection(strCon,"root","root" );
             stmt=conn.createStatement();
             sql="create database Jsp";
             ret=stmt.executeUpdate(sql);
             sql="create table customers("+
                 " Id int(6) unsigned NOT NULL auto_increment,"+
                 " Name varchar(20) default NULL,"+
                 " addTime timestamp NULL default NULL,"+
                 " Tel varchar(15) default NULL,"+
                 " Email varchar(20) default NULL,"+
                 " PRIMARY KEY (Id)"+
                 ")";
            ret=stmt.executeUpdate(sql);
           }
           catch(ClassNotFoundException e){
                e.printStackTrace();
                out.println("<h1>无法找到数据库驱动</h1>");
           }           out.println("<h1>新建数据库成功</h1>");
           DatabaseMetaData meta=conn.getMetaData();
           out.println("<br>");
           out.println("连接字："+meta.getURL()); 
           out.println("<br>"); 
           out.println("数据库产品"+meta.getDatabaseProductName()); 
           
           out.println("<br>"); 
           out.println("数据库版本"+meta.getDatabaseProductVersion()); 
           
           out.println("<br>"); 
           out.println("驱动程序"+meta.getDriverName()); 
           out.println("<br>"); 
           out.println("驱动程序版本"+meta.getDriverVersion()); 
           stmt.close();
           conn.close();
                 
    %>
   </font>
  </body>
     结果出现下面的异常：
   java.sql.SQLException: No database selected
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1056)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2938)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1601)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1710)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2436)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1402)
at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:977)
at org.apache.jsp.aaa_jsp._jspService(aaa_jsp.java:101)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
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 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:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:619)
请高手指点一下，这是什么原因?
          
 

解决方案 »

  1.   

    此回复为自动发出,仅用于显示而已，并无任何其他特殊作用
    楼主【guochaoguo】截止到2008-07-16 12:44:10的历史汇总数据(不包括此帖)：
    发帖的总数量:0                        发帖的总分数:0                        每贴平均分数:0                        
    回帖的总数量:1                        得分贴总数量:0                        回帖的得分率:0%                       
    结贴的总数量:0                        结贴的总分数:0                        
    无满意结贴数:0                        无满意结贴分:0                        
    未结的帖子数:0                        未结的总分数:0                        
    结贴的百分比:---------------------结分的百分比:---------------------
    无满意结贴率:---------------------无满意结分率:---------------------
    如何结贴请参考这里：http://topic.csdn.net/u/20080501/09/ef7ba1b3-6466-49f6-9d92-36fe6d471dd1.html
      

  2.   

    String strCon="jdbc:mysql://localhost:3306/"; 
    3306/后面加上数据库的名字
      

  3.   

    String strCon="jdbc:mysql://localhost:3306/"; 
    3306/后面加上数据库的名字
      

  4.   

    看看异常信息：No database selected
    没有选择数据库
      

  5.   

    呵呵，改了，但是还是有问题，运行JSP文件，浏览器上显示：
        --------------------------------------------------------------------------------type 异 常 报 告信 息 描 述 服务器遇到内部错误，无法满足这个访问请求异 常 org.apache.jasper.JasperException
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:512)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    起 因 java.lang.NullPointerException
    org.apache.jsp.aaa_jsp._jspService(aaa_jsp.java:109)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    注 意 完整的起因在Apache Tomcat/5.5.20里。不知道是不是配置问题
    --------------------------------------------------------------------------------
      

  6.   

    这已经跟你连接没什么关系了\Tomcat 5.5\work\Catalina\localhost
    用tomcat的话去tomcat安装路径\work\Catalina\localhost\你的工程\aaa_jsp.java:109去看下
    aaa_jsp.java:109这里报了空指针哈，查下看代码怎么写的就知道了