Hello Everyone

I am in a soup again :) I have a java class called SessionManager. As
its name implies, it keeps track of session.getAttribute and
session.setAttribute calls from a webserver (actually JSF + JBOSS
which is another nightmare :).

This is the crux: when I take away the JDBC calls everything works
fine except for the session persistence between server reboots. I
looked very hard and long at the code for almost a week now. Problem
is it works some times. I am unable to determine any pattern as to
what causes the code to fail. Could it be serialization of objects in/
out of Mysql? To go through every object that is ever put into a
session, it is a very lengthy task given that I am maintaining the
code (am not the writer of JSF back end beans).

I looked into some session persistence solutions (can't remember off
hand) and found them to be useful for a new project. Even using
hibernate is not an option for me. Since I already worked on this code
for several weeks now and the fact that it works some times, makes me
an optimist. :) Please help me out if you can.

BTW, these are the versions: jvm 1.5, jboss 4.0.2, Windows XP

Imports not shown... no compile problems....run time errors like
objects  returned null; Typically the select component of JSF gets a
null enumeration.

Thanks

/**
* This class provides methods to interact with the session. Its
exposes methods to put and get objects into
* Session and also exposes methods to do cleanup.
* @author rajasekhark
*/
public class SessionManager {

 /**
  * Sets an attribute in the session. These attributes would be
independent of the module,
  * and would be removed when the session expires. Or
<code>flush(HttpSession session)</code>
  * is called in the session.
  * @param key
  * @param value
  * @param session
  * @throws InvalidParameterException
  */
 public static void setAttribute(String key, Object value,
HttpSession session)
                                   throws InvalidParameterException{

if (value == null) {
    System.out.println("***********set attribute value null");
    System.exit(0);
}

    String sessid = (String)session.getId();
    System.out.println("sessionid=" + sessid);
    //open db  connection and save attribute if UID is set
    UserContext ucon = (UserContext)
session.getAttribute(FrameworkConstants.UserContextKey);
    String uid="";
    if (ucon != null)
        uid=ucon.getUid();
        String uname="";
    if (ucon != null) uname=ucon.getStrUserName();
if (uname == null) uname="";
System.out.println("SET ATTRIBUTE ******************uid=" + uid + "
uname=" + uname);
if (!sessid.equals("notset") && uid !=null && !uid.equals("")) {
Connection conn = null;
ResultSet rs=null;
PreparedStatement ps=null;

          try
          {
              String userName = "jboss";
              String password = "*********";
              String url = "jdbc:mysql://localhost:3306/jsfsession";
              Class.forName ("com.mysql.jdbc.Driver").newInstance ();
              conn = DriverManager.getConnection (url, userName,
password);
              System.out.println ("Setattribute Database connection
established for key=" + key);
ps = conn.prepareStatement("update session_tbl set val=?,
datestamp=NOW() where keyid=? and sessid=?");
        ps.setString(3, sessid);
        System.out.println("sessid=" + sessid);
        System.out.println("userid=" + uid);
        ps.setString(2, key);
        System.out.println("key=" + key);
ByteArrayOutputStream baos1 = new ByteArrayOutputStream();
ObjectOutputStream oout1 = new ObjectOutputStream(baos1);
oout1.writeObject(value);
oout1.close();
ps.setBytes(1, baos1.toByteArray());
        //ps.setObject(1, value);
        System.out.println("set blob");

        int r=ps.executeUpdate();

        ps.close();
        if (r==0) {
        System.out.println("can't update");
         ps = conn.prepareStatement("insert into session_tbl (sessid, uid,
keyid, val, uname, datestamp) values (?, ?, ?, ?, ?, NOW())");
        ps.setString(1, sessid);
        System.out.println("uid=" + uid);
        ps.setString(2, uid);
        ps.setString(3, key);
        System.out.println("key=" + key);
        ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
ObjectOutputStream oout2 = new ObjectOutputStream(baos2);
oout2.writeObject(value);
oout2.close();
ps.setBytes(4, baos2.toByteArray());
        //ps.setObject(4, value);
        System.out.println("set blob");
        ps.setString(5, uname);
        ps.executeUpdate();
        System.out.println("insert successful");
}
        ps.close();
          }
          catch (Exception e)
          {
              System.err.println ("Cannot connect to database server"
+ e.getMessage());
          }
          finally
          {
        if (ps != null) {
            try {
                ps.close();
            } catch (Exception e2) {};
        }
              if (conn != null)
              {
                  try
                  {
                      conn.close ();
                      System.out.println ("Setattribute Database
connection terminated");
                  }
                  catch (Exception e) { /* ignore close errors */ }
              }
          }
} //if
     try{

         //checks if the key is null or empty. Throws an exception if
it is.
         if(null == key || "" == key){
             Object [] values = new Object[1];
             values[0] = "key";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if
         //checks if the session is null or empty. Throws an
exception if it is.
         if(null == session){
             Object [] values = new Object[1];
             values[0] = "session";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if

         //set the session attribute
         session.setAttribute(key, value);
     System.out.println("setting attr in session key=" + key + " value="
+ value);
     }catch(RuntimeException ex){
         throw new InvalidParameterException(ex);
     }//end-try-catch
    System.out.println("leaving set attribute");
 }//end setAttribute

 /**
  * Sets an attribute in the session. These attribute pattern would
be the module name, and would
  * be removed when the session expires. Or <code>flush(String
pattern, HttpSession session)</code>
  * is called in the session.
  * @param pattern
  * @param key
  * @param value
  * @param session
  * @throws InvalidParameterException
  */
 public static void setPatternedAttribute(String pattern, String key,
Object value, HttpSession session)
                                         throws
InvalidParameterException{
    System.out.println("entered set patterned attribute");
     try{

         //checks if the key is null or empty. Throws an exception if
it is.
         if(null == key || "" == key){
             Object [] values = new Object[1];
             values[0] = "key";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if
         //checks if the session is null or empty. Throws an
exception if it is.
         if(null == session){
             Object [] values = new Object[1];
             values[0] = "session";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if

         //set the session attribute
         session.setAttribute(pattern + "_" +  key, value);
    System.out.println("setting pattern=" + pattern + " key=" + key + "
value=" + value);
     }catch(RuntimeException ex){
         throw new InvalidParameterException(ex);
     }//end-try-catch
 }

 /**
  * Gets the value corresponding to the key passed as parameter. It
iterates through all the
  * available keys in the session, locates the key passed as
parameter. If found it passes the
  * corresponding value, else it throws appropriate exception.
  * @param key
  * @param session
  * @return Object
  * @throws InvalidParameterException
  * @throws SessionKeyNotFoundException
  */
 public static Object getAttribute(String key, HttpSession session)
                                     throws
InvalidParameterException,

SessionKeyNotFoundException{
    System.out.println("entered get attribute*********");
String uid="";
     UserContext ucon = (UserContext)
session.getAttribute(FrameworkConstants.UserContextKey);
     String sessid="notset";
    if (ucon != null)
    uid=ucon.getUid();
    System.out.println("*********uid=" + uid);
    sessid=(String)session.getId();
    System.out.println("session  =" + sessid);

     Enumeration enumSessionKeys = null;
     Object returnValue = null;
     boolean bKeyFound = false;
     try{

         //checks if the key is null or empty. Throws an exception if
it is.
         if(null == key || key.equals("")){
             Object [] values = new Object[1];
             values[0] = "key";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if
         //checks if the session is null or empty. Throws an
exception if it is.
         if(null == session){
             Object [] values = new Object[1];
             values[0] = "session";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if

         //Get all the keys available in session.
         enumSessionKeys = session.getAttributeNames();

         //Iterate through all the keys in the enumSessionKeys
enumeration. If the key
         //is found populate returnValue with the corresponding
session value and set the
         //key found flag to true. The first if checks for those
attributes that are set
         //based on a key without a pattern. The second if is for the
attributes that are
         //set in the session based on a pattern.
         while(enumSessionKeys.hasMoreElements()){
        if (key.indexOf("userContext") > -1) break;
             String strCurrentKey =
(String)enumSessionKeys.nextElement();
             CharSequence keySeq = key.subSequence(0, key.length());
             System.out.println("keyinput=" + key + "keyseq=" +
keySeq + " strCurrentKey=<" + strCurrentKey + ">value=<" +
session.getAttribute(strCurrentKey));
        if((strCurrentKey).equals(key)){
                 returnValue = session.getAttribute(key);
                 bKeyFound = true;
        System.out.println("match1");
                 break;
             }//end-if
             else if(strCurrentKey.endsWith(key)){
                 returnValue = session.getAttribute(strCurrentKey);
                 bKeyFound = true;
        System.out.println("match2");
                 break;
             }//end-else-if
             else if((strCurrentKey).contains(keySeq)){
                 returnValue = session.getAttribute(strCurrentKey);
                 bKeyFound = true;
        System.out.println("match3");
                 break;
             }//end-else-if

}

if (bKeyFound) {
    System.out.println("Key =  " + key + " is  found");
    if (returnValue != null) return returnValue;
} else {
    System.out.println("key=" + key + " not found");
}
//
//open db  connection and save attribute IF the attribute is not
found
if ( !sessid.equals("notset") ) {
    Connection conn = null;
    ResultSet rs=null;
    PreparedStatement ps=null;
          try
          {
              String userName = "jboss";
              String password = "**************";
              String url = "jdbc:mysql://localhost:3306/jsfsession";
              Class.forName ("com.mysql.jdbc.Driver").newInstance ();
              conn = DriverManager.getConnection (url, userName,
password);
              System.out.println ("Getattribute Database connection
established. looking for key=" + key);
         ps = conn.prepareStatement("select  val from session_tbl where
keyid ='" + key + "' and sessid=? order by datestamp ASC");
        ps.setString(1, sessid);

        //ps.setString(1, strCurrentKey);
         rs=ps.executeQuery();
        if (rs.next()) {
            bKeyFound=true;
            System.out.println("Found it!");

            byte[] buf = rs.getBytes("val");
if (buf != null) {
System.out.println("buf not null in getattribute***********");
ObjectInputStream objectIn = new ObjectInputStream(
        new ByteArrayInputStream(buf));
        returnValue = objectIn.readObject();        //Contains the object

}
            //returnValue = rs.getObject("val");
        }
        rs.close();

        ps.close();
        if (!bKeyFound) {
        ps = conn.prepareStatement("select  val from session_tbl where keyid
like '%" + key + "' and sessid=? order by datestamp ASC");
        ps.setString(1, sessid);

        //ps.setString(1, strCurrentKey);
         rs=ps.executeQuery();
        if (rs.next()) {
            bKeyFound=true;
            System.out.println("Found it!");

            byte[] buf = rs.getBytes("val");
if (buf != null) {
System.out.println("buf not null in getattribute***********");
ObjectInputStream objectIn = new ObjectInputStream(
        new ByteArrayInputStream(buf));
        returnValue = objectIn.readObject();        //Contains the object

}
            //returnValue = rs.getObject("val");
        }
        rs.close();

        ps.close();
}//if
        if (!bKeyFound) {
        ps = conn.prepareStatement("select  val from session_tbl where
(keyid like '%" + key + "%' or keyid like '%" + key + "' or keyid like
'%" + key + "%') and sessid=? order by datestamp ASC");
        ps.setString(1, sessid);

        //ps.setString(1, strCurrentKey);
         rs=ps.executeQuery();
        if (rs.next()) {
            bKeyFound=true;
            System.out.println("Found it!");

            byte[] buf = rs.getBytes("val");
if (buf != null) {
System.out.println("buf not null in getattribute***********");
ObjectInputStream objectIn = new ObjectInputStream(
        new ByteArrayInputStream(buf));
        returnValue = objectIn.readObject();        //Contains the object

}
            //returnValue = rs.getObject("val");
        }
        rs.close();

        ps.close();
        }//if
          }
          catch (Exception e)
          {
              System.err.println ("Cannot connect to database server"
+ e.getMessage());
          }
          finally
          {
        try {
            rs.close();
        } catch (Exception e3) {};

        if (ps != null) {
            try {
                ps.close();
            } catch (Exception e2) {};
        }
              if (conn != null)
              {
                  try
                  {
                      conn.close ();
                      System.out.println ("Getattribute Database
connection terminated");
                  }
                  catch (Exception e) { /* ignore close errors */ }
              }
    }
}//if
if (bKeyFound) {
    setAttribute(key, returnValue, session);

}

//check if the key found flag is set to true. if not then throw
SessionKeyNotFoundException.
         if(!bKeyFound || returnValue == null ){
             Object [] values = new Object[1];
             values[0] = key;
             System.out.println("SessionManager about to throw
SessionKeyNotFoundException key="+key);
             throw new
SessionKeyNotFoundException("SessionKeyNotFoundException", values);
         }//end-if

return returnValue;
     }catch(RuntimeException ex){
         throw new InvalidParameterException(ex);
     }//end-try-catch

 }//end getAttribute

 /**
  * Removes the keys that follow a specified pattern (specified in
the input) from the session.
  * @param pattern
  * @param session
  * @throws InvalidParameterException
  */
 public static void flush(String pattern, HttpSession session)
                           throws InvalidParameterException{
    System.out.println("entered session flush");
     Enumeration enumSessionKeys = null; //enumeration that will hold
all the keys in the session.
     String key = "";  //key arrived while iterating.
     try{

         //checks if the key is null or empty. Throws an exception if
it is.
         if(null == pattern || "" == pattern){
             Object [] values = new Object[1];
             values[0] = "pattern";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if
         //checks if the session is null or empty. Throws an
exception if it is.
         if(null == session){
             Object [] values = new Object[1];
             values[0] = "session";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if

         //Get all the keys available in session.
         enumSessionKeys = session.getAttributeNames();

         //if the attributes in the session are not null, iterate
through all the available
         //keys and check if the pattern passed as input matches the
current key. If so then
         //remove the key from the session.
         if(null != enumSessionKeys){
             while(enumSessionKeys.hasMoreElements()){
                 key = (String)enumSessionKeys.nextElement();
                 if(key.startsWith(pattern)) {
                     session.removeAttribute(key);
             System.out.println("flush remove attrib=" + key);
                 }//end-if
             }//end-while
         }//end-if

     }catch(RuntimeException ex){
         throw new InvalidParameterException(ex);
     }//end-try-catch
System.out.println("leaving sessioni flush");
 }//end-flush

 /**
  * Invalidates the entire session.
  * @param session
  * @throws InvalidParameterException
  */
 public static void flush(HttpSession session)
                             throws InvalidParameterException{
    System.out.println("entered flush2");
     Enumeration enumSessionKeys = null;
     String key = "";  //key arrived while iterating.
     try{

         //checks if the session is null or empty. Throws an
exception if it is.
         if(null == session){
             Object [] values = new Object[1];
             values[0] = "session";
             throw new
InvalidParameterException("InvalidParameterException",values);
         }//end-if

         session.invalidate();

     }catch(RuntimeException ex){
         throw new InvalidParameterException(ex);
     }//end-try-catch

    System.out.println("Leafving flush2");
 }//end-flush

public static void fflush(HttpSession session)
                             throws InvalidParameterException{
    System.out.println("*****************entered fflush2");

    String sessid="notset";
    //if (ucon != null)
    //uid=ucon.getUid();
    sessid=(String)session.getId();
    System.out.println("sessionid=" + sessid);
    Connection conn = null;
    ResultSet rs=null;
    PreparedStatement ps=null;
          try
          {
              String userName = "jboss";
              String password = "*************";
              String url = "jdbc:mysql://localhost:3306/jsfsession";
              Class.forName ("com.mysql.jdbc.Driver").newInstance ();
              conn = DriverManager.getConnection (url, userName,
password);
              System.out.println ("Getattribute Database connection
established");
        ps=conn.prepareStatement("select uid from session_tbl where
sessid=?");
        ps.setString(1, sessid);
        rs=ps.executeQuery();
        String uid="";
        if (rs.next()) {
            uid=rs.getString("uid");
        }
        rs.close();
        if (uid != null && !uid.equals("")) {
            System.out.println("**********removing session for uid=" + uid);
            //UserManager.removeff(uid);
        }
        ps.close();
         ps = conn.prepareStatement("delete from session_tbl where
sessid=?");
        ps.setString(1, sessid);
        ps.executeUpdate();

        ps.close();
          }
          catch (Exception e)
          {
              System.err.println ("Cannot connect to database server"
+ e.getMessage());
          }
          finally
          {
        try {
            rs.close();
        } catch (Exception e3) {};

        if (ps != null) {
            try {
                ps.close();
            } catch (Exception e2) {};
        }
              if (conn != null)
              {
                  try
                  {
                      conn.close ();
                      System.out.println ("Getattribute Database
connection terminated");
                  }
                  catch (Exception e) { /* ignore close errors */ }
              }
    }
    System.out.println("*****************Leafving fflush2");
 }//end-flush
public static void fflushbyuserid(String uname, String uid)
                             throws InvalidParameterException{
    System.out.println("*****************entered fflush2 for user=" +
uname);

    Connection conn = null;
    ResultSet rs=null;
    PreparedStatement ps=null;
          try
          {
              String userName = "jboss";
              String password = "******";
              String url = "jdbc:mysql://localhost:3306/jsfsession";
              Class.forName ("com.mysql.jdbc.Driver").newInstance ();
              conn = DriverManager.getConnection (url, userName,
password);
              System.out.println ("Getattribute Database connection
established");
        /*******************
ps=conn.prepareStatement("select uid from session_tbl where uname=?");
        ps.setString(1, uname);
        rs=ps.executeQuery();
        String nuid="";
        if (rs.next()) {
            nuid=rs.getString("uid");
        }
        rs.close();
        ps.close();
         ps = conn.prepareStatement("delete from session_tbl where
uname=?");
        ps.setString(1, uname);
        ps.executeUpdate();

        ps.close();
*************************/
        if (uid != null && !uid.equals(""))
        UserManager.removeff(uid);
          }
          catch (Exception e)
          {
              System.err.println ("Cannot connect to database server"
+ e.getMessage());
          }
          finally
          {
        try {
            rs.close();
        } catch (Exception e3) {};

        if (ps != null) {
            try {
                ps.close();
            } catch (Exception e2) {};
        }
              if (conn != null)
              {
                  try
                  {
                      conn.close ();
                      System.out.println ("Getattribute Database
connection terminated");
                  }
                  catch (Exception e) { /* ignore close errors */ }
              }
    }
    System.out.println("*****************Leafving fflushbyuserid");
 }//end-flush
}