Holding/refreshing the MySQL-connection

Hey there,

I'm experimenting a bit with MySQL and because of just not being so dumb and creating a new connection for every statement i want to submit, i made a global connection in my class (shown below)
the problem is:
if the connection is not used for some minutes, it becomes invalid.
So i thought, why not just recreate the same connection using the same variable, nothing changed, just a refreshed connection.
But, how does my plugin know if it should refresh the connection?
Here is some code to show what i mean:

Code:

public class MySQL {

    private Connection cn = null;

    public MySQL(){

        try {
            Class.forName("com.mysql.jdbc.Driver");
            cn = DriverManager.getConnection( *** );

        } catch( Exception ex ) {
            System.out.println( ex );
            ex.printStackTrace();
        }
    }

    public void reconnect(){
        try {
            Class.forName("com.mysql.jdbc.Driver");
            cn = DriverManager.getConnection( *** );

        } catch( Exception ex ) {
            System.out.println( ex );
            ex.printStackTrace();
        }
    }

    public ResultSet showDbTable(String table) throws SQLException{
        Statement  st = null;
        ResultSet  rs = null;
        try {
            st = cn.createStatement();
            rs = st.executeQuery( "select * from " + table );

        } catch( SQLException ex ) {
            System.out.println( ex );
            ex.printStackTrace();
        }
        return rs;
    }

Thanks for help

 

I'd recommend using @alta189 's SQL Library.

 

I've already checked the code of the library and found nothing regarding a reconnect.
I just want to understand how this works, so I have to ask again

 

Check the connection status and if it's closed open a connection.