Lesson 6: Edit an action mapping

An action mapping represents an action that is run, and when running, it determines the flow of the application.

An action mapping is a configuration file entry that usually contains a reference to an action class. This entry can contain a reference to a form bean that the action can use, and can also define local forwards and exceptions that are visible only to this action. When you write code for a JavaServer Pages (JSP) page, you can refer to the action mapping to trigger an action.

The action class contains an execute method that is called when the form is submitted. In this method, you can supply the logic to determine if the calculated result is success (which is defined by the forward that points to the output JSP page), or failure (which is defined by the forward that points to the input JSP page).

To edit an action mapping:

In the Enterprise Explorer, double-click DayOfWeek\Java Resources: src\dayofweek.actions\ComputeDayAction.java to open it.
In the file, select all of the text and press Delete to remove it.

Copy and paste the following code into the file:

package com.ibm.dayofweek.actions;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.ibm.dayofweek.DateData;

/**
 * @version   1.0
 * @author
 */

public class ComputeDayAction extends Action {

  /**
   * Constructor
   */
  public ComputeDayAction() {

    super();

  }

  public ActionForward execute(
    ActionMapping mapping,
    ActionForm form,
    HttpServletRequest request,
    HttpServletResponse response)
    throws Exception {

    ActionErrors errors = new ActionErrors();
    ActionForward forward = new ActionForward();
    // return value
    DateData dateData = (DateData) form;
    int year;
    int month;
    int day;
    int dayOfWeek;
    int valcen;
    int valleap;
    int valyear;
    int valmon;
    int valday;
    int[] centuries = new int[4];
    int[] months = new int[13];
    String[] daysOfWeek = new String[7];
    centuries[0] = 2;
    centuries[1] = 0;
    centuries[2] = 5;
    centuries[3] = 3;
    months[1] = 5;
    months[2] = 1;
    months[3] = 0;
    months[4] = 3;
    months[5] = 5;
    months[6] = 1;
    months[7] = 3;
    months[8] = 6;
    months[9] = 2;
    months[10] = 4;
    months[11] = 0;
    months[12] = 2;
    daysOfWeek[0] = "Sunday";
    daysOfWeek[1] = "Monday";
    daysOfWeek[2] = "Tuesday";
    daysOfWeek[3] = "Wednesday";
    daysOfWeek[4] = "Thursday";
    daysOfWeek[5] = "Friday";
    daysOfWeek[6] = "Saturday";

    try {
      day = dateData.getDay();
      month = dateData.getMonth();
      year = dateData.getYear();
      if (month < 3) {
        year--; // Subtract 1 from year
      }
      valcen = centuries[year / 100 % 4];
      valleap = year % 100 / 4;
      valyear = year % 100 % 7;
      valmon = months[month];
      valday = day % 7;
      dayOfWeek = valcen + valleap + valyear + valmon + valday;
      dayOfWeek = dayOfWeek % 7;
      dateData.setDayOfWeek(daysOfWeek[dayOfWeek]);
      request.setAttribute("dateData", dateData);

    } catch (Exception e) {

      // Report the error using the appropriate name and ID.
      errors.add("name", new ActionError("id"));
      e.printStackTrace();
    }

    // If a message is required, save the specified key(s)
    // into the request for use by the tag. 

    if (!errors.isEmpty()) {
      saveErrors(request, errors);
      forward = mapping.findForward("failure");
    } else {
      forward = mapping.findForward("success");
    }

    // Finish with
    return (forward);

  }

}

Save and close the file.

Lesson 6: Edit an action mapping

Lesson checkpoint