PC World 1998 October/PCWorld_1998-10_cd.bin/software/prehled/inprise/JSAMPLES.Z/ResourcedDataSetExceptionHandler.java

Java Source | 1998-05-08 | 6.8 KB | 152 lines

/*
 * Copyright (c) 1997-1998 Borland International, Inc. All Rights Reserved.
 *
 * This SOURCE CODE FILE, which has been provided by Borland as part
 * of a Borland product for use ONLY by licensed users of the product,
 * includes CONFIDENTIAL and PROPRIETARY information of Borland.
 *
 * USE OF THIS SOFTWARE IS GOVERNED BY THE TERMS AND CONDITIONS
 * OF THE LICENSE STATEMENT AND LIMITED WARRANTY FURNISHED WITH
 * THE PRODUCT.
 *
 * IN PARTICULAR, YOU WILL INDEMNIFY AND HOLD BORLAND, ITS RELATED
 * COMPANIES AND ITS SUPPLIERS, HARMLESS FROM AND AGAINST ANY CLAIMS
 * OR LIABILITIES ARISING OUT OF THE USE, REPRODUCTION, OR DISTRIBUTION
 * OF YOUR PROGRAMS, INCLUDING ANY CLAIMS OR LIABILITIES ARISING OUT OF
 * OR RESULTING FROM THE USE, MODIFICATION, OR DISTRIBUTION OF PROGRAMS
 * OR FILES CREATED FROM, BASED ON, AND/OR DERIVED FROM THIS SOURCE
 * CODE FILE.
 */
package borland.samples.intl.application;

import java.awt.*;
import java.text.*;
import java.util.*;
import borland.jbcl.control.*;
import borland.jbcl.dataset.*;

import borland.samples.intl.beans.*;
import borland.samples.intl.beans.event.*;

/**
 * Resourceable DataSetExceptionHandler for the application.  In
 * AppDataModule's constructor, ResourcedDataSetExceptionHandler is
 * registered as the handler for DataSetExceptions for the
 * application.  Doing so results in our error handler, rather than
 * the standard handler, being called whenever a DataSetException
 * occurs.  By examining the Exception event's error code or message,
 * we can localize error messages displayed to the user for the proper
 * locale.  It is possible to provide error handlers to display
 * localized messages for specific error conditions, e.g, on
 * 'addError' or 'deleteError' events.  However, in this application
 * we take advantage of the fact that all errors are funneled into a
 * single error handler.
 */
public class ResourcedDataSetExceptionHandler implements ExceptionListener, LocaleChangeListener {
  private AppDataModule appDataModule;
  ResourceBundle textRes = java.util.ResourceBundle.getBundle("borland.samples.intl.application.resources.TextRes",
                                                    LocaleChangeManager.getLocale());
  ResourceBundle textRes2 = java.util.ResourceBundle.getBundle("borland.samples.intl.gui.resources.TextRes",
                                                     LocaleChangeManager.getLocale());
  protected MessageFormat formattedMessage = new MessageFormat(textRes.getString("enter_value"));

  public ResourcedDataSetExceptionHandler(AppDataModule appDataModule) {
    this.appDataModule = appDataModule;
    LocaleChangeManager.getLocaleChangeManager().addLocaleChangeListener(this);
  }

  public void exception(ExceptionEvent event) {
    Component component = event.getComponent();
    Frame frame = null;

    while (component != null) {
      if (component instanceof Frame) {
        frame = (Frame) component;
        break;
      }
      component = component.getParent();
    }

    if (frame == null) {
      frame = new Frame();
    }
    Message message = new Message();
    message.setFrame(frame);
    Object [] messageArgs;
    String messageString = null;
    int errorCode;

    if (event.getException() instanceof DataSetException) {
      errorCode = ((DataSetException) event.getException()).getErrorCode();
    } else {
      errorCode = -1;
    }

    // At least one required field is missing.
    // Find the empty field and display its name in an error message dialog.
    if (errorCode == ValidationException.INVALID_ROW_VALUES) {
      try {
        if (event.getDataSet() == appDataModule.getOrderDataSet()) {
          String [] requiredFields = new String [] { "payment_method", "credit_card_no", "card_expiration_date" };

          for (int i = 0; i < requiredFields.length; i++) {
            if (appDataModule.getOrderDataSet().getString(requiredFields[i]).length() == 0) {
              messageArgs = new Object [] { textRes2.getString(requiredFields[i]) };
              messageString = formattedMessage.format(messageArgs);
              break;
            }
          }
        } else if (event.getDataSet() == appDataModule.getCustomerDataSet()) {
          String [] requiredFields = new String [] { "last_name", "first_name", "address1", "city", "province",
                                                       "country" };
          for (int i = 0; i < requiredFields.length; i++) {
            if (appDataModule.getCustomerDataSet().getString(requiredFields[i]).length() == 0) {
              messageArgs = new Object [] { textRes.getString(requiredFields[i]) };
              messageString = formattedMessage.format(messageArgs);
              break;
            }
          }
        }
      } catch (Exception e) {
        borland.jbcl.util.Diagnostic.printStackTrace(e);
      }
      // A value in a column is less than the minimum allowed value.
      // Since the only minimum validation constraint we placed was on the
      // credit card expiration date field, display a localized
      // message indicating that the credit card has already expired.
    } else if ((errorCode == ValidationException.LESS_THAN_MIN) &&
               ((ValidationException) event.getException()).getErrorColumn().getColumnName().equals("card_expiration_date")) {
        messageString = textRes.getString("card_expired");
      // One or more characters necessary to satisfy an edit mask pattern
      // are missing.
    } else if (errorCode == ValidationException.INVALID_FORMAT) {
      messageString = textRes.getString("format_error");
      // User tried to edit a value in a read-only column.
    } else if (errorCode == ValidationException.READ_ONLY_COLUMN) {
      messageString = textRes.getString("read_only");
      // User tried inserting, deleting, or indirectly posting a row
      // which we deliberately denied using setEnableInsert
      // or setEnableDelete false.  Silently ignore it.
    } else if ((errorCode == ValidationException.INSERT_NOT_ALLOWED) ||
               (errorCode == ValidationException.DELETE_NOT_ALLOWED)) {
      return;
    }

    // If we didn't have a localized message for the error condition,
    // go ahead and display the message in the language of the current
    // locale.
    if (messageString == null) {
      messageString = event.getException().getMessage();
    }

    message.setLabels(new String[] {textRes.getString("OK")});
    message.setMessage(messageString);
    message.setVisible(true);
  }

  public void localeChanged(LocaleChangeEvent e) {
    textRes = java.util.ResourceBundle.getBundle("borland.samples.intl.application.resources.TextRes", e.getLocale());
    textRes2 = java.util.ResourceBundle.getBundle("borland.samples.intl.gui.resources.TextRes", e.getLocale());
  }
}