Java tutorial
/********************************************************************************** * $URL$ * $Id$ *********************************************************************************** * * Copyright (c) 2005, 2006, 2007, 2008 The Sakai Foundation * * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.tool.section.jsf; import java.sql.Time; import java.text.ParseException; import java.text.SimpleDateFormat; import java.text.DateFormatSymbols; import java.util.Calendar; import java.util.Comparator; import java.util.Date; import java.util.Locale; import javax.faces.application.FacesMessage; import javax.faces.context.FacesContext; import javax.faces.model.SelectItem; import org.apache.commons.lang.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.sakaiproject.jsf.util.ConversionUtil; import org.sakaiproject.tool.section.jsf.MessagingBean; import org.sakaiproject.util.ResourceLoader; import org.sakaiproject.time.cover.TimeService; /** * A utility to help deal with common tasks in JSF. * * @author <a href="mailto:jholtzman@berkeley.edu">Josh Holtzman</a> * */ public class JsfUtil { private static final Log log = LogFactory.getLog(JsfUtil.class); /** * As part of the crutch for JSF's inability to do validation on relative * values in different components. This pattern defines how times should * be displayed in the Section Info UI. */ public static final String TIME_PATTERN_DISPLAY = "h:mm"; /** * As part of the crutch for JSF's inability to do validation on relative * values in different components. This pattern defines how to parse and * format complete times (with hours, minutes, and am/pm marker). */ public static final String TIME_PATTERN_LONG = "h:mm a"; /** * As part of the crutch for JSF's inability to do validation on relative * values in different components. This pattern defines how to parse and * format abberviated times (with only hours and am/pm marker). */ public static final String TIME_PATTERN_SHORT = "h a"; /** * This is ISO-8601 date validation */ public static final String ISO_8601_DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss"; /** * To cut down on configuration noise, allow access to request-scoped beans from * session-scoped beans, and so on, this method lets the caller try to find * anything anywhere that Faces can look for it. * * WARNING: If what you're looking for is a managed bean and it isn't found, * it will be created as a result of this call. */ public static final Object resolveVariable(String name) { FacesContext context = FacesContext.getCurrentInstance(); Object result = context.getApplication().getVariableResolver().resolveVariable(context, name); if (log.isDebugEnabled()) log.debug("JSF variable " + name + " resolved to " + result); return result; } /** * Adds an error message for display on a page when the page is guaranteed * not to be displayed via a redirect. * * @param message */ public static void addErrorMessage(String message) { FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_ERROR, message, null)); } /** * Adds an error message for display on a component when the page is guaranteed * not to be displayed via a redirect. * * @param message * @param componentId */ public static void addErrorMessage(String message, String componentId) { FacesContext.getCurrentInstance().addMessage(componentId, new FacesMessage(FacesMessage.SEVERITY_ERROR, message, null)); } /** * Adds an info message for display on a page when the page is guaranteed * not to be displayed via a redirect. * * @param message */ public static void addInfoMessage(String message) { FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, message, null)); } /** * Adds an info message for display on a page even if faces sends the user * to the page via a redirect. * * @param message */ public static void addRedirectSafeInfoMessage(String message) { MessagingBean mb = (MessagingBean) resolveVariable("messagingBean"); mb.addMessage(new FacesMessage(FacesMessage.SEVERITY_INFO, message, null)); } /** * Adds a warning message for display on a page even if faces sends the user * to the page via a redirect. * * @param message */ public static void addRedirectSafeWarnMessage(String message) { MessagingBean mb = (MessagingBean) resolveVariable("messagingBean"); mb.addMessage(new FacesMessage(FacesMessage.SEVERITY_WARN, message, null)); } /** * Gets a localized message from the message bundle. */ public static String getLocalizedMessage(String key) { ResourceLoader rl = new ResourceLoader("sections"); return rl.getString(key); } /** * Gets a localized message from the message bundle and formats it using the * parameter array. * * @param key * @param params * @return */ public static String getLocalizedMessage(String key, String[] params) { ResourceLoader rl = new ResourceLoader("sections"); return rl.getFormattedMessage(key, params); } /** * Gets a value from the request parameter map, as provided by the faces * context. * * @param string * @return */ public static String getStringFromParam(String string) { return (String) FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get(string); } /** * Converts a string and a boolean (am) into a java.sql.Time object. * * @param str * @param am * @return */ public static Time convertStringToTime(String str, boolean am) { if (StringUtils.trimToNull(str) == null) { return null; } // Set the am/pm flag to ensure that the time is parsed properly if (am) { str = str + " " + new DateFormatSymbols(new ResourceLoader().getLocale()).getAmPmStrings()[0]; } else { str = str + " " + new DateFormatSymbols(new ResourceLoader().getLocale()).getAmPmStrings()[1]; } String pattern = (str.indexOf(':') != -1) ? JsfUtil.TIME_PATTERN_LONG : JsfUtil.TIME_PATTERN_SHORT; SimpleDateFormat sdf = new SimpleDateFormat(pattern, new ResourceLoader().getLocale()); sdf.setTimeZone(TimeService.getLocalTimeZone()); Date date; try { date = sdf.parse(str); } catch (ParseException pe) { throw new RuntimeException("A bad date made it through validation! This should never happen!"); } return ConversionUtil.convertDateToTime(date, am); } public static String convertTimeToString(Time time) { if (time == null) { return null; } SimpleDateFormat sdf = new SimpleDateFormat(JsfUtil.TIME_PATTERN_DISPLAY, new ResourceLoader().getLocale()); sdf.setTimeZone(TimeService.getLocalTimeZone()); return sdf.format(time); } /** * Converts an ISO-8601 formatted string into a Calendar object * * @param str * @return Calendar */ public static Calendar convertISO8601StringToCalendar(String str) { if (StringUtils.trimToNull(str) == null) { return null; } SimpleDateFormat sdf = new SimpleDateFormat(JsfUtil.ISO_8601_DATE_FORMAT); sdf.setTimeZone(TimeService.getLocalTimeZone()); try { Date date = sdf.parse(str); Calendar cal = Calendar.getInstance(); cal.setTime(date); return cal; } catch (Exception e) { log.warn("Bad ISO 8601 date in sections: " + str); } return null; } public static final Comparator getSelectItemComparator() { return new Comparator() { public int compare(Object o1, Object o2) { SelectItem item1 = (SelectItem) o1; SelectItem item2 = (SelectItem) o2; return item1.getLabel().toString().compareTo(item2.getLabel().toString()); } }; } }