Question

I have a method that takes a string value as a parameter and then checks if that string value exists in the database! The method should return true if the string value already exist and false otherwise! Before i run the method i get a compilation error ” missing return statement”! Does anyone spot an error in the code below ?

 public boolean checkID(String sid)
 {
    try 
    {
        String sessionID = null;
        if(dBConnection.connect())
        {
            Connection con = dBConnection.getConnection();
            String query = "SELECT sidvalue FROM sessionid where tokenvalue='" + sid + "'";
            Statement pstmt = con.createStatement();
            ResultSet resultset = pstmt.executeQuery(query);

            while (resultset.next())
            {
                sessionID = resultset.getString(1);
                if(sid.equalsIgnoreCase(sessionID))
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            dBConnection.disconnect();     
        }//End of If statement

    }//End of Try block
    catch (Exception e)
    {
        System.out.println(e);
        return false;
    }
 }//End of method

Answer 1

What if the execution doesn’t pass to the if statement and/or while loop? There is no return value for such cases. Use a boolean variable or false value to return. Just add a return false; statement after this line dBConnection.disconnect();, i.e. after the while loop inside the if statement of your try block, it will be done.

By the way, I suggest you to use database disconnection statement in a finally clause, not inside try block. It’s probable that dBConnection.disconnect(); will not be executed if your method returns any value inside the while loop. Move this line dBConnection.disconnect(); to a finally block just after the catch block like this:

try
{
...
}
catch(Exception e)
{
...
}
finally
{
   dBConnection.disconnect();   
}