Compile error

I am trying to connect to my database using the following code but get the following errors:
C:\Program Files\Apache Group\Tomcat 4.1\webapps\ID-HCI-TIP\WEB-INF\classes\com\idhcitip\SessionCounter.java:109: unreported exception java.lang.ClassNotFoundException; must be caught or declared to be thrown
Class.forName("org.gjt.mm.mysql.Driver").newInstance();
^
C:\Program Files\Apache Group\Tomcat 4.1\webapps\ID-HCI-TIP\WEB-INF\classes\com\idhcitip\SessionCounter.java:109: unreported exception java.lang.InstantiationException; must be caught or declared to be thrown
Class.forName("org.gjt.mm.mysql.Driver").newInstance();


private Connection getConnection() throws SQLException
{
Connection Conn = null;
String host="localhost";
String user="root";
String pass="";
String db="idhcitipcount";
String conn;

try
{
Class.forName("org.gjt.mm.mysql.Driver").newInstance();

// create connection string
conn = "jdbc:mysql://" + host + "/" + db + "?user=" + user + "&password=" +pass;

// pass database parameters to JDBC driver
Conn = DriverManager.getConnection(conn);
}

catch(SQLException e)
{
}

return Conn;


}
Any ideas?

* are you importing the DB driver files (all of them) into your page? as in

* are your DB drivers in your tomcat commons/lib folder? they should be...

Elie

There's no need to import the sql driver. Java is telling you that the line "Class.forName("org.gjt.mm.mysql.Driver").newInstance();" can cause an "InstantiationException" or a "ClassNotFoundException". You'll have to catch those exceptions as follows:

Put that just above where you're catching your SQLException and it should be OK.
~ishnid

I added the catches in but it has just created the same problem in the place where the old function was called.
How do I stop the class trouble when calling the function as well?


C:\Program Files\Apache Group\Tomcat 4.1\webapps\ID-HCI-TIP\WEB-INF\classes\idhcitip\SessionCounter.java:53: unreported exception java.lang.ClassNotFoundException; must be caught or declared to be thrown
conn = getConnection();


private void updateDatabaseCount() throws SQLException, ClassNotFoundException
{
Connection conn = null;
try
{
conn = getConnection();
Statement stmt = conn.createStatement();
stmt.execute("UPDATE session_count SET count = count + " + newSessions);
newSessions = 0;
}

finally
{
try
{
conn.close();
}
catch(SQLException e)
{
}

}
}
private Connection getConnection() throws SQLException, ClassNotFoundException
{
Connection Conn = null;
String host="localhost";
String user="root";
String pass="";
String db="idhcitipcount";
String conn;

try
{
Class.forName("org.gjt.mm.mysql.Driver").newInstance();

// create connection string
conn = "jdbc:mysql://" + host + "/" + db + "?user=" + user + "&password=" +pass;

// pass database parameters to JDBC driver
Conn = DriverManager.getConnection(conn);
}

catch (ClassNotFoundException e)
{
// do stuff with e (if you want)
}
catch (InstantiationException e)
{
// do stuff with this e (if you want)
}

catch(SQLException e)
{
}

catch(Exception e)
{
}

return Conn;


}
}

You shouldn't be throwing AND catching the exceptions - the facility to throw exceptions is that you don't have to catch them in the method they occur in, though you will have to catch them wherever you called the method from.

In other words, you should either catch the ClassNotFoundException, SQLException etc. at the end of the getConnection() method or throw them, in which case you will have to have the catch blocks for them wherever you called the method from (in this case, it's called from your updateDatabaseCount() method).

~ishnid

Exceptions tutorial
http://java.sun.com/docs/books/tuto...ial/exceptions/