validationhelper.java

我在加拿大学习的一个比较复杂的在线银行程序.

package com.ebusiness.ebank.action;


import java.text.SimpleDateFormat;
import java.text.DateFormatSymbols;

import java.util.Date ;
import java.util.Locale;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.commons.validator.Field;
import org.apache.commons.validator.GenericValidator;
import org.apache.commons.validator.ValidatorAction;
import org.apache.commons.validator.ValidatorUtil;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.util.StrutsValidatorUtil;
import org.apache.struts.Globals;

import com.ebusiness.ebank.util.Constants;
/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author unascribed
 * @version 1.0
 */

public class ValidationHelper  {


  public static boolean validateDate( Object bean,
                                      ValidatorAction va,
                                      Field field,
                                      ActionErrors errors, HttpServletRequest request) {

    HttpSession session = request.getSession(false) ;
    Locale userLocale = (Locale)session.getAttribute(Globals.LOCALE_KEY);

    String value = null;
    if (isString(bean)) {
      value = (String)bean;
    } else {
      value = ValidatorUtil.getValueAsString(bean, field.getProperty());
    }

    SimpleDateFormat formatter ;
    if (userLocale.equals(Locale.ENGLISH)) {
      formatter= new SimpleDateFormat("dd-MMM-yyyy");
    } else {
      DateFormatSymbols dateSymbols = new DateFormatSymbols(Locale.FRENCH) ;
      dateSymbols.setShortMonths(Constants.newFrenchShortMonths);
      formatter =  new SimpleDateFormat("dd-MMM-yy", dateSymbols) ;
    }

    boolean retValue = true;
    if (!GenericValidator.isBlankOrNull(value)) {
        try {
           Date returnDate = formatter.parse(value);
           if ( formatter.format(returnDate).equalsIgnoreCase(value) == false) {
             throw new Exception() ;
           }

        } catch (Exception e){
            errors.add(field.getKey(),
            StrutsValidatorUtil.getActionError(request, va, field));
            retValue = false;
        }

    }
    return retValue;
  }

  private static boolean isString(Object o) {
    if (o == null) {
      return (true);
    }
    return (String.class.isInstance(o));
  }

}