Java tutorial
/* * $Id: ValidWhen.java 471754 2006-11-06 14:55:09Z husted $ * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.apache.struts.validator.validwhen; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.commons.validator.Field; import org.apache.commons.validator.Validator; import org.apache.commons.validator.ValidatorAction; import org.apache.commons.validator.util.ValidatorUtils; import org.apache.struts.action.ActionMessage; import org.apache.struts.action.ActionMessages; import org.apache.struts.util.MessageResources; import org.apache.struts.validator.Resources; import javax.servlet.http.HttpServletRequest; import java.io.StringReader; /** * This class contains the validwhen validation that is used in the * validator-rules.xml file. * * @since Struts 1.2 */ public class ValidWhen { /** * Commons Logging instance. */ private static final Log log = LogFactory.getLog(ValidWhen.class); /** * The message resources for this package. */ private static MessageResources sysmsgs = MessageResources .getMessageResources("org.apache.struts.validator.LocalStrings"); /** * Returns true if <code>obj</code> is null or a String. */ private static boolean isString(Object obj) { return (obj == null) ? true : String.class.isInstance(obj); } /** * Checks if the field matches the boolean expression specified in * <code>test</code> parameter. * * @param bean The bean validation is being performed on. * @param va The <code>ValidatorAction</code> that is currently being * performed. * @param field The <code>Field</code> object associated with the * current field being validated. * @param errors The <code>ActionMessages</code> object to add errors to * if any validation errors occur. * @param request Current request object. * @return <code>true</code> if meets stated requirements, * <code>false</code> otherwise. */ public static boolean validateValidWhen(Object bean, ValidatorAction va, Field field, ActionMessages errors, Validator validator, HttpServletRequest request) { Object form = validator.getParameterValue(Validator.BEAN_PARAM); String value = null; boolean valid = false; int index = -1; if (field.isIndexed()) { String key = field.getKey(); final int leftBracket = key.indexOf("["); final int rightBracket = key.indexOf("]"); if ((leftBracket > -1) && (rightBracket > -1)) { index = Integer.parseInt(key.substring(leftBracket + 1, rightBracket)); } } if (isString(bean)) { value = (String) bean; } else { value = ValidatorUtils.getValueAsString(bean, field.getProperty()); } String test = null; try { test = Resources.getVarValue("test", field, validator, request, true); } catch (IllegalArgumentException ex) { String logErrorMsg = sysmsgs.getMessage("validation.failed", "validwhen", field.getProperty(), ex.toString()); log.error(logErrorMsg); String userErrorMsg = sysmsgs.getMessage("system.error"); errors.add(field.getKey(), new ActionMessage(userErrorMsg, false)); return false; } // Create the Lexer ValidWhenLexer lexer = null; try { lexer = new ValidWhenLexer(new StringReader(test)); } catch (Exception ex) { String logErrorMsg = "ValidWhenLexer Error for field ' " + field.getKey() + "' - " + ex; log.error(logErrorMsg); String userErrorMsg = sysmsgs.getMessage("system.error"); errors.add(field.getKey(), new ActionMessage(userErrorMsg, false)); return false; } // Create the Parser ValidWhenParser parser = null; try { parser = new ValidWhenParser(lexer); } catch (Exception ex) { String logErrorMsg = "ValidWhenParser Error for field ' " + field.getKey() + "' - " + ex; log.error(logErrorMsg); String userErrorMsg = sysmsgs.getMessage("system.error"); errors.add(field.getKey(), new ActionMessage(userErrorMsg, false)); return false; } parser.setForm(form); parser.setIndex(index); parser.setValue(value); try { parser.expression(); valid = parser.getResult(); } catch (Exception ex) { String logErrorMsg = "ValidWhen Error for field ' " + field.getKey() + "' - " + ex; log.error(logErrorMsg); String userErrorMsg = sysmsgs.getMessage("system.error"); errors.add(field.getKey(), new ActionMessage(userErrorMsg, false)); return false; } if (!valid) { errors.add(field.getKey(), Resources.getActionMessage(validator, request, va, field)); return false; } return true; } }