Overriding Initialize

Override the class initializer init() to initialize or allocate resources for the servlet instance's life, such as a counter. The init() method runs after the servlet is instantiated but before it accepts any requests. For more information, see the servlet API specification.

All init() methods must call super.init(ServletConfig) to set their scope. This makes the servlet's configuration object available to other servlet methods. If this call is omitted, a 500 SC_INTERNAL_SERVER_ERROR displays in the browser when the servlet starts up.

The following example of the init() method initializes a counter by creating a public integer variable called thisMany:

public class myServlet extends HttpServlet {
        int thisMany;
public void init (ServletConfig config) throws ServletException
        {
           super.init(config);
           thisMany = 0;
       }
       }

Now other servlet methods can access the variable.