Java tutorial
/* * RHQ Management Platform * Copyright (C) 2005-2008 Red Hat, Inc. * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation version 2 of the License. * * 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ package org.rhq.enterprise.gui.legacy.util; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.struts.Globals; import org.apache.struts.action.ActionErrors; import org.apache.struts.action.ActionMapping; import org.apache.struts.action.ActionMessage; import org.apache.struts.action.ActionMessages; import org.rhq.enterprise.gui.legacy.AttrConstants; import org.rhq.enterprise.gui.legacy.WebUser; import org.rhq.enterprise.gui.legacy.beans.ReturnPath; public class SessionUtils { private static final Log log = LogFactory.getLog(SessionUtils.class); // Limit the size of the return stack so that it // doesn't grow to infinite proportions. private static final int RETURN_STACK_MAX_SIZE = 128; /** * Retrieve the cached <code>WebUser</code> representing the user. * * @param session the http session * @return null if the session or its attribute 'webUser' is invalid, the user otherwise */ public static WebUser getWebUser(HttpSession session) { if (session == null) { return null; } Object attr = session.getAttribute(AttrConstants.WEBUSER_SES_ATTR); if (attr == null) { return null; } WebUser user = (WebUser) attr; log.debug("Loading WebUser"); /* Subject subject = user.getSubject(); Integer sessionId = subject.getSessionId(); subject = LookupUtil.getSubjectManager().loadUserConfiguration(subject.getId()); subject.setSessionId(sessionId); // put the transient data back into our new subject user = new WebUser(subject); // reset */ return user; } public static void setWebUser(HttpSession session, WebUser user) { if (user == null) { session.removeAttribute(AttrConstants.WEBUSER_SES_ATTR); } else { session.setAttribute(AttrConstants.WEBUSER_SES_ATTR, user); } } /** * Retrieve the array of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute */ public static Integer[] getList(HttpSession session, String attr) { Object list = session.getAttribute(attr); Integer[] pendingIds = null; try { pendingIds = (Integer[]) list; } catch (ClassCastException e) { List pendingIdsList = (List) list; pendingIds = (Integer[]) pendingIdsList.toArray(new Integer[pendingIdsList.size()]); } if (pendingIds == null) { pendingIds = new Integer[0]; } return pendingIds; } /** * Retrieve the <code>List</code> of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute */ public static List getListAsList(HttpSession session, String attr) { Object list = session.getAttribute(attr); List pendingIds = null; try { pendingIds = (List) list; } catch (ClassCastException e) { Integer[] pendingIdsArray = (Integer[]) list; pendingIds = Arrays.asList(pendingIdsArray); } if (pendingIds == null) { pendingIds = new ArrayList(); } return pendingIds; } /** * Retrieve the <code>List</code> of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute */ @SuppressWarnings("unchecked") public static List<String> getListAsListStr(HttpSession session, String attr) { Object list = session.getAttribute(attr); List<String> pendingIds = null; try { pendingIds = (List<String>) list; } catch (ClassCastException e) { String[] pendingIdsArray = (String[]) list; pendingIds = Arrays.asList(pendingIdsArray); } if (pendingIds == null) { pendingIds = new ArrayList<String>(); } return pendingIds; } /** * Merge the given ids into the array of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute * @param ids the ids to be added */ public static void addToList(HttpSession session, String attr, List ids) { /* copy the selected pending ids over to the available * ids. those that were copied will not be included in the final list of available users generated by theform * prepare action. */ List pendingIds = (List) session.getAttribute(attr); if (pendingIds == null) { pendingIds = new ArrayList(); } session.setAttribute(attr, mergeIds(pendingIds, ids)); } public static void addToList(HttpSession session, String attr, Integer[] ids) { addToList(session, attr, Arrays.asList(ids)); } /** * Merge the given ids into the array of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute * @param ids the ids to be added */ public static void addToListStr(HttpSession session, String attr, List ids) { /* copy the selected pending ids over to the available * ids. those that were copied will not be included in the final list of available users generated by theform * prepare action. */ List pendingIds = (List) session.getAttribute(attr); if (pendingIds == null) { pendingIds = new ArrayList(); } session.setAttribute(attr, mergeStrIds(pendingIds, ids)); } public static void addToList(HttpSession session, String attr, String[] ids) { addToListStr(session, attr, Arrays.asList(ids)); } /** * Remove the given ids from the array of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute * @param ids the ids to be removed */ public static void removeFromList(HttpSession session, String attr, List ids) { /* remove the selected pending ids from the current list *of pending ids. */ List pendingIds = (List) session.getAttribute(attr); if (pendingIds == null) { pendingIds = new ArrayList(); } session.setAttribute(attr, grepIds(pendingIds, ids)); } public static void removeFromList(HttpSession session, String attr, Integer[] ids) { removeFromList(session, attr, Arrays.asList(ids)); } /** * Remove the given ids from the array of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute * @param ids the ids to be removed */ public static void removeFromListStr(HttpSession session, String attr, List ids) { /* remove the selected pending ids from the current list *of pending ids. */ List pendingIds = (List) session.getAttribute(attr); if (pendingIds == null) { pendingIds = new ArrayList(); } session.setAttribute(attr, grepStrIds(pendingIds, ids)); } public static void removeFromList(HttpSession session, String attr, String[] ids) { removeFromListStr(session, attr, Arrays.asList(ids)); } /** * Remove the array of pending ids stored under the named session attribute. * * @param session the http session * @param attr the name of the session attribute */ public static void removeList(HttpSession session, String attr) { session.removeAttribute(attr); } /** * Retrieve the "return path" that locates the point at which a subflow was included into a primary workflow. * * @param session the http session */ public static String getReturnPath(HttpSession session) { LinkedList stack = (LinkedList) session.getAttribute(AttrConstants.RETURN_LOC_SES_ATTR); if ((stack == null) || stack.isEmpty()) { return null; } ReturnPath returnPath = (ReturnPath) stack.getFirst(); return returnPath.getPath(); } /** * Set the "returnPath", the possible point of origin for a workflow. * * @param session the http session * @param path the return path */ public static void setReturnPath(HttpSession session, String path) { setReturnPath(session, path, Boolean.FALSE); } /** * Set the "returnPath," the possible point of origin for a worklow * * @param session The http session. * @param path The return path url represented as a String. * @param ignore */ public static void setReturnPath(HttpSession session, String path, Boolean ignore) { LinkedList stack = (LinkedList) session.getAttribute(AttrConstants.RETURN_LOC_SES_ATTR); ReturnPath returnPath = new ReturnPath(); if (stack == null) { stack = new LinkedList(); } returnPath.setPath(path); returnPath.setIgnore(ignore); stack.addFirst(returnPath); // don't let it grow too large. if (stack.size() > RETURN_STACK_MAX_SIZE) { stack.removeLast(); } session.setAttribute(AttrConstants.RETURN_LOC_SES_ATTR, stack); } /** * clear out the return path stack. */ public static void resetReturnPath(HttpSession session) { LinkedList stack = new LinkedList(); session.setAttribute(AttrConstants.RETURN_LOC_SES_ATTR, stack); } /** * Unset the "return path" that locates the point at which a subflow was included into a primary workflow. * * @param session the http session */ public static void unsetReturnPath(HttpSession session) { LinkedList retstack = (LinkedList) session.getAttribute(AttrConstants.RETURN_LOC_SES_ATTR); if ((retstack != null) && (retstack.size() >= 1)) { retstack.removeFirst(); } } /** * Retrieve wether the "return path" should be paid attention to for new. should default to false, which means that * it is not ignored. * * @param session the http session * * @return whether or not to ignore the return path */ public static Boolean getReturnPathIgnoredForOk(HttpSession session) { LinkedList stack = (LinkedList) session.getAttribute(AttrConstants.RETURN_LOC_SES_ATTR); if ((stack == null) || stack.isEmpty()) { return Boolean.FALSE; } ReturnPath returnPath = (ReturnPath) stack.getFirst(); if (returnPath == null) { return Boolean.FALSE; } return returnPath.getIgnore(); } /** * Unset the "return path" that locates the point at which a subflow was included into a primary workflow. * * @param session the http session */ public static void unsetReturnPathIgnoredForOk(HttpSession session) { LinkedList stack = (LinkedList) session.getAttribute(AttrConstants.RETURN_LOC_SES_ATTR); ReturnPath returnPath = (ReturnPath) stack.getFirst(); returnPath.setIgnore(Boolean.TRUE); } /** * Remove any old workflows * * @param session * @param workflowName */ public static void clearWorkflow(HttpSession session, String workflowName) { HashMap workflows = (HashMap) session.getAttribute(AttrConstants.WORKFLOW_SES_ATTR); if (workflows != null) { workflows.remove(workflowName); } } /** * Takes the current returnPath and pushes it onto the workflow's stack. * * @param session The HttpSesion to get and save the workflow to/from * @param mapping Use the input attribute from this mapping if a returnPath is not defined in the current * session. * @param workflowName The name of the workflow scope to save the input under. */ public static void pushWorkflow(HttpSession session, ActionMapping mapping, String workflowName) { HashMap workflows = (HashMap) session.getAttribute(AttrConstants.WORKFLOW_SES_ATTR); if (workflows == null) { workflows = new HashMap(); } String returnPath = getReturnPath(session); if (returnPath == null) { returnPath = mapping.getInput(); } LinkedList urlStack = (LinkedList) workflows.get(workflowName); // whacking getIsFirst.. for some reason, even if i set the // property to false in struts-config.xml, it's still getting // set back to true. i can't have this, so i'm whacking the // check altogether. doesn't seem to harm anything. -bcm 7/9/03 // if (urlStack == null || mapping.getIsFirst().booleanValue()) { if (urlStack == null) { urlStack = new LinkedList(); } urlStack.addLast(returnPath); workflows.put(workflowName, urlStack); session.setAttribute(AttrConstants.WORKFLOW_SES_ATTR, workflows); } /** * Takes the current returnPath and pops it off of the workflow's stack. * * @param session The HttpSesion to get and save the workflow to/from * @param workflowName The name of the workflow scope to save the input under. * @return return path or null if it can't be retrieved */ public static String popWorkflow(HttpSession session, String workflowName) { HashMap workflows = (HashMap) session.getAttribute(AttrConstants.WORKFLOW_SES_ATTR); if (workflows == null) { return null; } LinkedList urlStack = (LinkedList) workflows.get(workflowName); if ((urlStack == null) || urlStack.isEmpty()) { return null; } String returnUrl = (String) urlStack.removeLast(); workflows.put(workflowName, urlStack); session.setAttribute(AttrConstants.WORKFLOW_SES_ATTR, workflows); return returnUrl; } /** * Returns the size of a workflow's stack. * * @param session The HttpSesion to get and save the workflow to/from * @param workflowName The name of the workflow scope to save the input under. */ public static int countWorkflow(HttpSession session, String workflowName) { HashMap workflows = (HashMap) session.getAttribute(AttrConstants.WORKFLOW_SES_ATTR); if (workflows == null) { return 0; } LinkedList urlStack = (LinkedList) workflows.get(workflowName); if ((urlStack == null) || urlStack.isEmpty()) { return 0; } return urlStack.size(); } private static List grepIds(List all, List matches) { if ((all == null) || (matches == null)) { return new ArrayList(); } // build an index of matches HashSet index = new HashSet(); Iterator mi = matches.iterator(); while (mi.hasNext()) { index.add(mi.next()); } // find everything that's not a match ArrayList ids = new ArrayList(); Iterator ai = all.iterator(); while (ai.hasNext()) { Integer id = (Integer) ai.next(); if (!index.contains(id)) { ids.add(id); } } return ids; } /** * searches for strings which does not match */ private static List grepStrIds(List pending, List newItems) { if ((pending == null) || (newItems == null)) { return new ArrayList(); } // build an index of matches HashSet index = new HashSet(); Iterator mi = newItems.iterator(); while (mi.hasNext()) { index.add(mi.next()); } // find everything that's not a match ArrayList ids = new ArrayList(); Iterator ai = pending.iterator(); while (ai.hasNext()) { String id = (String) ai.next(); if (!index.contains(id)) { ids.add(id); } } return ids; } private static List mergeIds(List orig, List added) { if ((orig == null) && (added == null)) { return new ArrayList(); } if (orig == null) { return added; } if (added == null) { return orig; } // build an index of orig and add originals ArrayList ids = new ArrayList(); HashSet index = new HashSet(); Iterator oi = orig.iterator(); while (oi.hasNext()) { Object next = oi.next(); index.add(next); ids.add(next); } // add anything that's not in the index Iterator ai = added.iterator(); while (ai.hasNext()) { Integer id = (Integer) ai.next(); if (!index.contains(id)) { ids.add(id); } } return ids; } /** * same as the mergeIds except using strings IDs of form: . */ private static List mergeStrIds(List orig, List added) { if ((orig == null) && (added == null)) { return new ArrayList(); } if (orig == null) { return added; } if (added == null) { return orig; } // build an index of orig and add originals ArrayList ids = new ArrayList(); HashSet index = new HashSet(); Iterator oi = orig.iterator(); while (oi.hasNext()) { Object next = oi.next(); index.add(next); ids.add(next); } // add anything that's not in the index Iterator ai = added.iterator(); while (ai.hasNext()) { String id = (String) ai.next(); if (!index.contains(id)) { ids.add(id); } } return ids; } /** * Set a confirmation message upon completion of a user action. * * @param session The servlet session object * @param key the message resource key */ public static void setConfirmation(HttpSession session, String key) { ActionMessage msg = new ActionMessage(key); ActionMessages msgs = new ActionMessages(); msgs.add(ActionMessages.GLOBAL_MESSAGE, msg); if (session != null) { session.setAttribute(Globals.MESSAGE_KEY, msgs); } } /** * Set a confirmation message with a replacement value upon completion of a user action. * * @param session The servlet session object * @param key the message resource key * @param value0 the replacement value */ public static void setConfirmation(HttpSession session, String key, Object value0) { ActionMessage msg = new ActionMessage(key, value0); ActionMessages msgs = new ActionMessages(); msgs.add(ActionMessages.GLOBAL_MESSAGE, msg); if (session != null) { session.setAttribute(Globals.MESSAGE_KEY, msgs); } } public static void unsetConfirmation(HttpSession session, String key) { session.removeAttribute(Globals.MESSAGE_KEY); } /** * Set an error message when a user action fails with a user-level error. * * @param session The servlet session object * @param key the message resource key */ public static void setError(HttpSession session, String key) { setError(session, key, ActionMessages.GLOBAL_MESSAGE); } /** * Set an error message when a user action fails with a user-level error. * * @param session The servlet session object * @param key the message resource key * @param property the form property for which the error occurred */ public static void setError(HttpSession session, String key, String property) { ActionMessage err = new ActionMessage(key); ActionErrors errs = new ActionErrors(); errs.add(property, err); if (session != null) { session.setAttribute(Globals.ERROR_KEY, errs); } } /** * Set an error message with a replacement value when a user action fails with a user-level error. * * @param session The servlet session object * @param key the message resource key * @param value0 the replacement value */ public static void setError(HttpSession session, String key, Object value0) { setError(session, key, value0, ActionMessages.GLOBAL_MESSAGE); } /** * Set an error message with a replacement value when a user action fails with a user-level error. * * @param session The servlet session object * @param key the message resource key * @param value0 the replacement value * @param property the form property for which the error occurred */ public static void setError(HttpSession session, String key, Object value0, String property) { ActionMessage err = new ActionMessage(key, value0); ActionMessages errs = new ActionErrors(); errs.add(property, err); if (session != null) { session.setAttribute(Globals.ERROR_KEY, errs); } } public static void unsetError(HttpSession session) { if (session != null) { session.removeAttribute(Globals.ERROR_KEY); } } /** * Move the attribute from the session to request scope. * * @param request The request to move the attribute to. * @param key Key indicating the attribute to move scope. */ public static void moveAttribute(HttpServletRequest request, String key) { HttpSession session = request.getSession(false /* dont' create new one */); if (session != null) { request.setAttribute(key, session.getAttribute(key)); session.removeAttribute(key); } } }