title: JDBC Query excecution
body: <p>I am facing an issue while executing queries.I use the same resultSet and statement for excecuting all the queries.Now I face an intermittent SQlException saying that connection is already closed.Now we have to either have separate resultSet for each query or have lock like structure.Can anyone tell which is better.I think introducing locks will slow down the process.Am I right?</p>
  
  <p>Update:
  To be more clear.The error may happen because the finally block gets called before all the queries get executed and the connection gets closed and exception will be thrown.</p>
  
  <p>This is the exception I get</p>
  
  <blockquote>
    <p>java.sql.SQLException: Connection has
    already been closed.  at
    weblogic.jdbc.wrapper.PoolConnection.checkConnection(PoolConnection.java:81)
      at
    weblogic.jdbc.wrapper.ResultSet.preInvocationHandler(ResultSet.java:68)
      at
    weblogic.jdbc.wrapper.ResultSet_com_informix_jdbc_IfxResultSet.next(Unknown
    Source)   at
    com.test.test.execute(test.java:76)<br>
      at
    org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:413)
      at
    org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:225)
      at
    org.apache.struts.action.ActionServlet.process(ActionServlet.java:1858)
      at
    org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:459)
      at
    javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
      at
    javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
      at
    weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1077)
      at
    weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:465)
      at
    weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:348)
      at
    weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:7047)
      at
    weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
      at
    weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
      at
    weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3902)
      at
    weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2773)
      at
    weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:224)
      at
    weblogic.kernel.ExecuteThread.run(ExecuteThread.java:183)</p>
  </blockquote>
  
  <p>Sample code:</p>
  
  <pre><code>ResultSet rst=null; 
  Statement stmt=null; 
  Connection con=DBConnection.getConnection();
   stmt=con.createStatement();
   rst=stmt.executeQuery("select * from dual");
   while(rst.next())
   { : ://Some code } 
  rst=stmt.executeQuery("select * from doctor where degree="BM");
   while(rst.next())
   { //blah blah } 
  finally
   { 
  //close con,rst and stmt 
  } 
  </code></pre>