Could someone help me with this error: java.sql.SQLException: Closed Connec

Question

My code:
<%@ include file="../setupcache.jsp"%>
<%
if(connectionPool_dig==null){
%>
<p>Could not connect to database. Please try again, thank!</p>
<%          
     return ;
Connection con = connectionPool_dig.getConnection();
if(con==null){
%>
<p>Could not connect to database. Please try again, thank!</p>
<%          
     return;
     String file = request.getParameter("m_FILE");
          file = "a";
     String sql = " SELECT *"+
          " FROM "+
          " FILEUPLOAD, SUBJECT"+
          " WHERE "+
          " FILEUPLOAD.SUBJECTCODE = SUBJECT.CODE AND UPPER(FILEUPLOAD.FILENAME) LIKE(UPPER(?))";
     PreparedStatement stmt = con.prepareStatement(sql);
     stmt.setString(1,"%"+file+"%");
     ResultSet rs = stmt.executeQuery();
     while(rs.next()){
          out.println("<br>"+rs.getString(1));
          out.println("<br>"+rs.getString(2));
          out.println("<br>"+rs.getString(3));
          out.println("<br>"+rs.getString(4));
     rs.close();
     stmt.close();
try{
     con.close();
}catch(SQLException e){}
%>
it usualy generate that error (once wrong then right then wrong....), but if I don't close connection (con.close), it work well. Could some one help me!

Answer 1

Hi,
I think that it should be better that returning the Connection
instance back to the Connection Pool. The connection
should not be close by you. it should controlled by the
connection pool mechanism. So I think that you should
check out your connection pool usage document for the
right usage.
If your code is the case, the connection in connection
pool will get less and your connection pool mechanism
may need to reallocate a new one for application. I
don't think that it is right.
good luck,
Alfred Wu