Java tutorial
/* * NOTE: This copyright does *not* cover user programs that use HQ * program services by normal system calls through the application * program interfaces provided as part of the Hyperic Plug-in Development * Kit or the Hyperic Client Development Kit - this is merely considered * normal use of the program, and does *not* fall under the heading of * "derived work". * * Copyright (C) [2004, 2005, 2006], Hyperic, Inc. * This file is part of HQ. * * HQ is free software; you can redistribute it and/or modify * it under the terms version 2 of the GNU General Public License as * published by the Free Software Foundation. This program is distributed * in the hope that it will be useful, but WITHOUT ANY WARRANTY; without * even the implied warranty of MERCHANTABILITY or FITNESS FOR A * PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA. */ package org.hyperic.util.validator.common; import java.io.InputStream; import java.io.IOException; import java.util.Map; import java.util.ResourceBundle; import java.util.Locale; import java.util.Iterator; import java.text.MessageFormat; import org.apache.commons.validator.Field; import org.apache.commons.validator.Form; import org.apache.commons.validator.Validator; import org.apache.commons.validator.ValidatorResults; import org.apache.commons.validator.ValidatorResources; import org.apache.commons.validator.ValidatorResult; import org.apache.commons.validator.ValidatorException; import org.apache.commons.validator.ValidatorAction; import org.xml.sax.SAXException; /** * Encapsulates most of specific jakarta commons validator logic and * provides access to validation results. * <p>NOTE: Very heavily commented so as to persuade others to use and * extend. The commons validation logic is a little bulky and awkward * so consider this as a good place to put any further wrapper methods.</p> */ public class CommonValidator { private ResourceBundle _properties = null; // message strings private ValidatorResults _validatorResults = null; // results of validation private String _resourceName = null; // current xml resource. private ValidatorResources _validatorResources = null; // commons-v object /** * Simple constructor with property resourcebundle containing localized * messages **/ public CommonValidator(ResourceBundle properties) { _properties = properties; } private void setResourceName(String rName) { _resourceName = rName; } private void setValidatorResults(ValidatorResults results) { _validatorResults = results; } public ValidatorResults getValidatorResults() { return _validatorResults; } public String getResourceName() { return _resourceName; } /** * Simple getter for current Validator Resources. null until validate * is first run **/ public ValidatorResources getValidatorResources() { return _validatorResources; } /** * Gets and/or initializes validatorResources before returning it. Init- * ialization is expensive so only perform it if necessary. * Note: (1) CALLER's responsibility to close InputStream. * (2) XML Resources always looked for in same package as Bean. **/ private void setValidatorResources(String resourceName, Object bean, InputStream in) throws IOException, SAXException { if (getResourceName() == null || !getResourceName().equals(resourceName)) { // remember this resource setResourceName(resourceName); // Read in the XMLfile in = bean.getClass().getResourceAsStream(resourceName); // create a new "validator" resources object. This thing contains // FormSets stored against locale. _validatorResources = new ValidatorResources(in); } } /** * Perform all form-specific the validation. All form specific validation * is performed and then finally a CommonValidatorException object will be * thrown if (AND ONLY IF) validation errors were detected. The exception * object will contain a collection of error Strings see * {@ref CommonValidatorException}. * * @param validationMappingRes A String containing the name of the * mapping resource file. * @param formName A String containing the name of the form containing * the validation action references. * @param beanInstance An instance of the bean to apply validation on. * @throws CommonValidatorException - Exception containing collection of * messages. **/ public void validate(String validationMappingRes, String formName, Object beanInstance) throws CommonValidatorException, SAXException { InputStream xmlStream = null; CommonValidatorException cve = null; ValidatorResults results; try { // Start by setting the "ValidatorResources" object. Its only // created if necessary. Contains FormSets stored against locale. setValidatorResources(validationMappingRes, beanInstance, xmlStream); // Get the form for the current locale and Bean. Form form = _validatorResources.getForm(Locale.getDefault(), formName); // Instantiate the validator (coordinates the validation // while the ValidatorResources implements the validation) Validator validator = new Validator(_validatorResources, formName); // Tell the validator which bean to validate against. validator.setParameter(Validator.BEAN_PARAM, beanInstance); // Get the results results = validator.validate(); // Localize a reference for future access. setValidatorResults(results); // Iterate over each of the properties of the Bean which had messages. Iterator propertyNames = results.getPropertyNames().iterator(); while (propertyNames.hasNext()) { // There were errors. Instantiate CVE String propertyName = (String) propertyNames.next(); // Get the Field associated with that property in the Form Field field = (Field) form.getField(propertyName); // Look up the formatted name of the field from the Field arg0 String prettyFieldName = _properties.getString(field.getArg(0).getKey()); // Get the result of validating the property. ValidatorResult result = results.getValidatorResult(propertyName); // Get all the actions run against the property, and iterate // over their names. Check for invalid results. Map actionMap = result.getActionMap(); Iterator keys = actionMap.keySet().iterator(); while (keys.hasNext()) { String actName = (String) keys.next(); // Get the Action for that name. ValidatorAction action = _validatorResources.getValidatorAction(actName); if (!result.isValid(actName)) { String message = _properties.getString(action.getMsg()); Object[] args = { prettyFieldName }; if (cve == null) { cve = new CommonValidatorException(); } cve.addMessage(MessageFormat.format(message, args)); } } } } catch (IOException ex) { // Note: This exception shouldn't be reported to user since it // wasn't likely caused by user input. ex.printStackTrace(); //log this } catch (ValidatorException ex) { // Note: This exception shouldn't bubble up to user since it // wasn't likely caused by user input. ex.printStackTrace(); //log this } finally { // Make sure we close the input stream. if (xmlStream != null) try { xmlStream.close(); } catch (Exception e) { } // Lastly, if we had any invalid fields, throw CVE. if (cve != null) throw cve; } } }