Database Error: RSR0009: Resource not available for pool. Wait-time expired

Question

i am occassionally receiving the following error during database connections in my servlet:
Database Error: RSR0009: Resource not available for pool [webAdvisorTestPool]. Wait-time expired
i understand that this is a result of a connection leak from improper closure of my Connection object, but i thought that i was properly closing my connection.
i can get the error if i do the following steps:
1) access my login page and enter login credentials.
2) submit the login which then hits the Authentication servlet.
3) Authentication servlet authenticates and takes me to home page.
4) hit the back button to get back to the login page.
5) repeat this process until i hit the Max Pool Size (from web server).
6) then i get the error message
here are some details:
i have an Authentication servlet; here is the pertinent code from that servlet:
try {     // retrieve the user and add the User object to the session     DAO dao = new DAO();     Person authenticUser = dao.getPerson(userID, password);     session.setAttribute("validUser", authenticUser);     redirectPage = mapping.findForward("success"); }
i also have a DAO object that handles all of my DB transactions (and you can see from my code above that the Authentication servlet is using that object); here is the pertinant code from that servlet:
public DAO() {     datasource = "java:comp/env/jdbc/webAdvisorTest"; } public Person getPerson(String userID, String password)     throws ObjectNotFoundException {     // JDBC variables     DataSource ds = null;     Connection conn = null;     PreparedStatement stmt = null;     ResultSet results = null;     // User variables     Person validUser = null;     try     {         // Retrieve the DataSource from JNDI         InitialContext ctx = new InitialContext();         // if this statement fails, NamingException is thrown         ds = (DataSource)ctx.lookup(datasource);         // get DB connection and perform SQL operations         conn = ds.getConnection();         // User variables         String validUserID = null;         String validFName = null;         String validLName = null;         String validEmail = null;         // get DB connection and perform SQL operations         conn = ds.getConnection();         stmt = conn.prepareStatement(PERSON_QUERY);         stmt.setString(1, userID);         stmt.setString(2, password);         results = stmt.executeQuery();         // iterate through the results         if (results.next())         {             validUserID = results.getString("id");             validFName = results.getString("first_name");             validLName = results.getString("last_name");             validUser = new Person(validUserID, validFName, validLName);         }     }     // handle SQL errors     catch(SQLException e)     {         e.printStackTrace(System.err);         throw new RuntimeException("Database Error: " + e.getMessage());     }     // handle JNDI errors     catch(NamingException e)     {         throw new RuntimeException("JNDI Error: " + e.getMessage());     }     // clean up resources     finally     {         doClosure(results, stmt, conn);     }     // if the user was not found, throw ObjectNotFoundException     if(validUser == null)     {         throw new ObjectNotFoundException();     }     return validUser; } protected void doClosure(ResultSet results, PreparedStatement stmt,     Connection conn) {     if (results != null)     {         try { results.close(); }         catch (SQLException e) { e.printStackTrace(System.err); }     }     if (stmt != null)     {         try { stmt.close(); }         catch (SQLException e) { e.printStackTrace(System.err); }     }     if (conn != null)     {         try         {             System.out.println("R18Resources.conn before close: " + conn);             conn.close();             System.out.println("R18Resources.conn after close: " + conn);             System.out.println("R18Resources.conn is closed? " +                 conn.isClosed());         }         catch (SQLException e)         {             System.out.println("R18Resource conn close error: " +                 e.getMessage());         }     } }
as you can see, i've added some print statements in my connection closure block. based on my output log, each connection is being properly closed and i am not encountering any errors during that closing block.
any ideas???
Message was edited by:
millerand

Answer 1

Please try the following code in your doClosure method. Replace your code with the following code.
public void doClosure(ResultSet pResultSet, Statement pStmt, Connection pConn) throws Exception {
try {
               if (pResultSet != null) {
                    pResultSet.close();
                    pResultSet = null;
          } catch (SQLException se) {
          logger.error( se );
          } finally {
               try {
                    if (pStmt != null) {
                         pStmt.close();
                         pStmt = null;
               } catch (SQLException se) {
               logger.error(se);
               } finally {
                    try {
                         if (pConn != null) {
                              pConn.close();
                              pConn = null;
                    } catch (SQLException se) {
                    logger.error(se);
And let me know if you still face this issue. What is the application server you are using?