Java tutorial
/* * The Gemma project * * Copyright (c) 2006 University of British Columbia * * Licensed 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 ubic.gemma.util; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.Enumeration; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * RequestUtil utility class * <p> * Good ol' copy-n-paste from <a href="http://www.javaworld.com/javaworld/jw-02-2002/ssl/utilityclass.txt"> * http://www.javaworld.com/javaworld/jw-02-2002/ssl/utilityclass.txt</a> which is referenced in the following article: * <a href="http://www.javaworld.com/javaworld/jw-02-2002/jw-0215-ssl.html"> * http://www.javaworld.com/javaworld/jw-02-2002/jw-0215-ssl.html</a> * <p> * From Appfuse. * * @author pavlidis * @version $Id: RequestUtil.java,v 1.4 2012/06/18 22:58:34 paul Exp $ */ public class RequestUtil { private static final String STOWED_REQUEST_ATTRIBS = "ssl.redirect.attrib.stowed"; private transient static Log log = LogFactory.getLog(RequestUtil.class); /** * Creates query String from request body parameters */ public static String getRequestParameters(HttpServletRequest aRequest) { // set the ALGORIGTHM as defined for the application // ALGORITHM = (String) aRequest.getAttribute(Constants.ENC_ALGORITHM); Map<String, Object> m = aRequest.getParameterMap(); return createQueryStringFromMap(m, "&").toString(); } /** * Builds a query string from a given map of parameters * * @param m A map of parameters * @param ampersand String to use for ampersands (e.g. "&" or "&" ) * @return query string (with no leading "?") */ public static StringBuffer createQueryStringFromMap(Map<String, Object> m, String ampersand) { StringBuffer aReturn = new StringBuffer(""); Set<Entry<String, Object>> aEntryS = m.entrySet(); Iterator<Entry<String, Object>> aEntryI = aEntryS.iterator(); while (aEntryI.hasNext()) { Entry<String, Object> aEntry = aEntryI.next(); Object o = aEntry.getValue(); if (o == null) { append(aEntry.getKey(), "", aReturn, ampersand); } else if (o instanceof String) { append(aEntry.getKey(), o, aReturn, ampersand); } else if (o instanceof String[]) { String[] aValues = (String[]) o; for (int i = 0; i < aValues.length; i++) { append(aEntry.getKey(), aValues[i], aReturn, ampersand); } } else { append(aEntry.getKey(), o, aReturn, ampersand); } } return aReturn; } /** * Appends new key and value pair to query string * * @param key parameter name * @param value value of parameter * @param queryString existing query string * @param ampersand string to use for ampersand (e.g. "&" or "&") * @return query string (with no leading "?") */ private static StringBuffer append(Object key, Object value, StringBuffer queryString, String ampersand) { if (queryString.length() > 0) { queryString.append(ampersand); } try { queryString.append(URLEncoder.encode(key.toString(), "UTF-8")); queryString.append("="); queryString.append(URLEncoder.encode(value.toString(), "UTF-8")); } catch (UnsupportedEncodingException e) { // won't happen since we're hard-coding UTF-8 } return queryString; } /** * Stores request attributes in session * * @param aRequest the current request */ public static void stowRequestAttributes(HttpServletRequest aRequest) { if (aRequest.getSession().getAttribute(STOWED_REQUEST_ATTRIBS) != null) { return; } Enumeration<String> e = aRequest.getAttributeNames(); Map<String, Object> map = new HashMap<String, Object>(); while (e.hasMoreElements()) { String name = e.nextElement(); map.put(name, aRequest.getAttribute(name)); } aRequest.getSession().setAttribute(STOWED_REQUEST_ATTRIBS, map); } /** * Returns request attributes from session to request * * @param aRequest DOCUMENT ME! */ public static void reclaimRequestAttributes(HttpServletRequest aRequest) { Map<String, Object> map = (Map<String, Object>) aRequest.getSession().getAttribute(STOWED_REQUEST_ATTRIBS); if (map == null) { return; } Iterator<String> itr = map.keySet().iterator(); while (itr.hasNext()) { String name = itr.next(); aRequest.setAttribute(name, map.get(name)); } aRequest.getSession().removeAttribute(STOWED_REQUEST_ATTRIBS); } /** * Convenience method to set a cookie * * @param response * @param name * @param value * @param path */ public static void setCookie(HttpServletResponse response, String name, String value, String path) { if (log.isDebugEnabled()) { log.debug("Setting cookie '" + name + "' on path '" + path + "'"); } Cookie cookie = new Cookie(name, value); cookie.setSecure(false); cookie.setPath(path); cookie.setMaxAge(3600 * 24 * 30); // 30 days response.addCookie(cookie); } /** * Convenience method to get a cookie by name * * @param request the current request * @param name the name of the cookie to find * @return the cookie (if found), null if not found */ public static Cookie getCookie(HttpServletRequest request, String name) { Cookie[] cookies = request.getCookies(); Cookie returnCookie = null; if (cookies == null) { return returnCookie; } for (int i = 0; i < cookies.length; i++) { Cookie thisCookie = cookies[i]; if (thisCookie.getName().equals(name)) { // cookies with no value do me no good! if (!thisCookie.getValue().equals("")) { returnCookie = thisCookie; break; } } } return returnCookie; } /** * Convenience method for deleting a cookie by name * * @param response the current web response * @param cookie the cookie to delete * @param path the path on which the cookie was set (i.e. /appfuse) */ public static void deleteCookie(HttpServletResponse response, Cookie cookie, String path) { if (cookie != null) { // Delete the cookie by setting its maximum age to zero cookie.setMaxAge(0); cookie.setPath(path); response.addCookie(cookie); } } /** * Convenience method to get the application's URL based on request variables. NOTE: this is pretty useless if * running behind a proxy. */ public static String getAppURL(HttpServletRequest request) { StringBuffer url = new StringBuffer(); int port = request.getServerPort(); if (port < 0) { port = 80; // Work around java.net.URL bug } String scheme = request.getScheme(); url.append(scheme); url.append("://"); url.append(request.getServerName()); if ((scheme.equals("http") && (port != 80)) || (scheme.equals("https") && (port != 443))) { url.append(':'); url.append(port); } url.append(request.getContextPath()); return url.toString(); } }