/**
* $Id: RequestUtils.java 67 2009-04-14 07:10:48Z azeckoski $
* $URL: http://entitybus.googlecode.com/svn/tags/entitybus-1.0.8/utils/src/main/java/org/sakaiproject/entitybus/util/request/RequestUtils.java $
* RequestUtils.java - entity-broker - Jul 28, 2008 7:41:28 AM - azeckoski
**************************************************************************
* Copyright (c) 2008 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.osedu.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.entitybus.util.request;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.sakaiproject.entitybus.EntityView;
import org.sakaiproject.entitybus.entityprovider.extension.Formats;
import org.sakaiproject.entitybus.entityprovider.extension.RequestStorage;
import org.sakaiproject.entitybus.entityprovider.search.Order;
import org.sakaiproject.entitybus.entityprovider.search.Restriction;
import org.sakaiproject.entitybus.entityprovider.search.Search;
import org.sakaiproject.entitybus.exception.EntityException;
import org.sakaiproject.entitybus.providers.EntityRequestHandler;
import org.sakaiproject.entitybus.utils.TemplateParseUtil;
/**
* Contains a set of static utility methods for working with requests
*
* @author Aaron Zeckoski (azeckoski @ gmail.com)
*/
public class RequestUtils {
private static final String DIVIDER = "||";
private static final String ENTITY_REDIRECT_CHECK = "_entityRedirectCheck";
/**
* A map from mimetypes to format constants
*/
public static Map<String, String> mimeTypeToFormat;
/**
* A map from format constants to mimetypes
*/
public static Map<String, String> formatToMimeType;
/**
* A map from extensions to format constants
*/
public static Map<String, String> extensionsToFormat;
static {
mimeTypeToFormat = new LinkedHashMap<String, String>(12);
mimeTypeToFormat.put(Formats.ATOM_MIME_TYPE, Formats.ATOM);
mimeTypeToFormat.put(Formats.FORM_MIME_TYPE, Formats.FORM);
mimeTypeToFormat.put(Formats.HTML_MIME_TYPE, Formats.HTML);
mimeTypeToFormat.put("application/xhtml+xml", Formats.HTML);
mimeTypeToFormat.put(Formats.JSON_MIME_TYPE, Formats.JSON);
mimeTypeToFormat.put("text/json", Formats.JSON); // this is not really valid
mimeTypeToFormat.put("application/*", Formats.JSON);
mimeTypeToFormat.put(Formats.RSS_MIME_TYPE, Formats.RSS);
mimeTypeToFormat.put(Formats.TXT_MIME_TYPE, Formats.TXT);
mimeTypeToFormat.put("text/*", Formats.TXT);
mimeTypeToFormat.put(Formats.XML_MIME_TYPE, Formats.XML);
mimeTypeToFormat.put("text/xml", Formats.XML); // this is not really valid
formatToMimeType = new LinkedHashMap<String, String>(7);
formatToMimeType.put(Formats.ATOM, Formats.ATOM_MIME_TYPE);
formatToMimeType.put(Formats.FORM, Formats.FORM_MIME_TYPE);
formatToMimeType.put(Formats.HTML, Formats.HTML_MIME_TYPE);
formatToMimeType.put(Formats.JSON, Formats.JSON_MIME_TYPE);
formatToMimeType.put(Formats.RSS, Formats.RSS_MIME_TYPE);
formatToMimeType.put(Formats.TXT, Formats.TXT_MIME_TYPE);
formatToMimeType.put(Formats.XML, Formats.XML_MIME_TYPE);
extensionsToFormat = new LinkedHashMap<String, String>(20);
extractExtensionsIntoMap(Formats.ATOM, Formats.ATOM_EXTENSIONS, extensionsToFormat);
extractExtensionsIntoMap(Formats.FORM, Formats.FORM_EXTENSIONS, extensionsToFormat);
extractExtensionsIntoMap(Formats.HTML, Formats.HTML_EXTENSIONS, extensionsToFormat);
extractExtensionsIntoMap(Formats.JSON, Formats.JSON_EXTENSIONS, extensionsToFormat);
extractExtensionsIntoMap(Formats.RSS, Formats.RSS_EXTENSIONS, extensionsToFormat);
extractExtensionsIntoMap(Formats.TXT, Formats.TXT_EXTENSIONS, extensionsToFormat);
extractExtensionsIntoMap(Formats.XML, Formats.XML_EXTENSIONS, extensionsToFormat);
}
/**
*
*/
private static void extractExtensionsIntoMap(String format, String[] extensions, Map<String, String> map) {
for (String extension : extensions) {
map.put(extension, format);
}
}
/**
* Handles the redirect to a URL from the current location,
* the URL should be relative for a forward, otherwise it will be a redirect <br/>
* NOTE: You should perform no actions after call this method,
* you should simply pass control back to the handler
* @param redirectURL the URL to redirect to (relative or absolute)
* @param forward if false, use redirect (this should be the default),
* if true use forward, note that we can only forward from your webapp back to your servlets and
* a check will be performed to see if this is the case, if it is not
* (anything with a "http", a non-matching prefix, and anything with a query string) will be switched to redirect automatically
* @param req the current request
* @param res the current response
* @throws IllegalArgumentException is the params are invalid
*/
public static void handleURLRedirect(String redirectURL, boolean forward, HttpServletRequest req, HttpServletResponse res) {
if (redirectURL == null || "".equals(redirectURL)) {
throw new IllegalArgumentException("The redirect URL must be set and cannot be null");
}
if (req == null || res == null) {
throw new IllegalArgumentException("The request and response must be set and cannot be null");
}
if (redirectURL.startsWith("http:") || redirectURL.startsWith("https:")
|| RequestUtils.containsQueryString(redirectURL)) {
forward = false;
} else {
// we allow forwarding ONLY if the current webapp path matches the redirect path
String webapp = req.getContextPath();
if (webapp != null && webapp.length() > 0) {
if (redirectURL.startsWith(webapp + "/")) {
redirectURL = redirectURL.substring(webapp.length());
forward = true;
} else if (redirectURL.length() > 1
&& redirectURL.startsWith(webapp.substring(1) + "/")) {
redirectURL = redirectURL.substring(webapp.length() - 1);
forward = true;
} else {
forward = false;
}
}
}
if (forward) {
// check for infinite forwarding
String curRedirect = DIVIDER + redirectURL + DIVIDER;
if (req.getAttribute(ENTITY_REDIRECT_CHECK) != null) {
String redirectCheck = (String) req.getAttribute(ENTITY_REDIRECT_CHECK);
if (redirectCheck.contains(curRedirect)) {
throw new IllegalStateException("Infinite forwarding loop detected with attempted redirect to ("+redirectURL+"), path to failure: "
+ redirectCheck.replace(DIVIDER+DIVIDER, " => ").replace(DIVIDER, "") + " => " + redirectURL);
}
redirectCheck += curRedirect;
req.setAttribute(ENTITY_REDIRECT_CHECK, redirectCheck);
} else {
req.setAttribute(ENTITY_REDIRECT_CHECK, curRedirect);
}
RequestDispatcher rd = req.getRequestDispatcher(redirectURL);
try {
rd.forward(req, res);
} catch (ServletException e) {
throw new RuntimeException("Failure with servlet while forwarding to '"+redirectURL+"': " + e.getMessage(), e);
} catch (IOException e) {
throw new RuntimeException("Failure with encoding while forwarding to '"+redirectURL+"': " + e.getMessage(), e);
}
} else {
res.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
try {
res.sendRedirect(redirectURL);
} catch (IOException e) {
throw new RuntimeException("Failure with encoding while redirecting to '"+redirectURL+"': " + e.getMessage(), e);
}
}
}
/**
* Simple check to see if a URL appears to contain a query string,
* true if it does, false otherwise
*/
private static boolean containsQueryString(String URL) {
int lastEquals = URL.lastIndexOf('=');
int qMark = URL.indexOf('?');
if (lastEquals > 0 && qMark > 0 && lastEquals > qMark) {
return true;
}
return false;
}
/**
* Gets the correct info out of the request method and places it into the entity view and
* identifies if this is an output (read) or input (write) request
* @param req the request
* @param view the entity view to update
* @return true if output request OR false if input request
* @throws EntityException if the request has problems
*/
public static boolean isRequestOutput(HttpServletRequest req, EntityView view) {
boolean output = false;
String method = req.getMethod() == null ? EntityView.Method.GET.name() : req.getMethod().toUpperCase().trim();
if (EntityView.Method.GET.name().equals(method)) {
view.setMethod(EntityView.Method.GET);
output = true;
} else if (EntityView.Method.HEAD.name().equals(method)) {
view.setMethod(EntityView.Method.HEAD);
output = true;
} else {
// identify the action based on the method type or "_method" attribute
if (EntityView.Method.DELETE.name().equals(method)) {
view.setViewKey(EntityView.VIEW_DELETE);
view.setMethod(EntityView.Method.DELETE);
} else if (EntityView.Method.PUT.name().equals(method)) {
view.setViewKey(EntityView.VIEW_EDIT);
view.setMethod(EntityView.Method.PUT);
} else if (EntityView.Method.POST.name().equals(method)) {
String _method = req.getParameter(EntityRequestHandler.COMPENSATE_METHOD);
if (_method == null) {
if (view.getEntityReference().getId() == null) {
// this better be a create request or list post
view.setViewKey(EntityView.VIEW_NEW);
} else {
// this could be an edit
view.setViewKey(EntityView.VIEW_NEW);
// view.setViewKey(EntityView.VIEW_EDIT);
}
} else {
_method = _method.toUpperCase().trim();
if (EntityView.Method.DELETE.name().equals(_method)) {
view.setViewKey(EntityView.VIEW_DELETE);
} else if (EntityView.Method.PUT.name().equals(_method)) {
if (view.getEntityReference().getId() == null) {
// this should be a modification of a list
view.setViewKey(EntityView.VIEW_NEW);
} else {
// this better be an edit of an entity
view.setViewKey(EntityView.VIEW_EDIT);
}
} else {
throw new EntityException("Unable to handle POST request with _method, unknown method (only PUT/DELETE allowed): " + _method,
view.getEntityReference()+"", HttpServletResponse.SC_BAD_REQUEST);
}
}
view.setMethod(EntityView.Method.POST);
} else {
throw new EntityException("Unable to handle request method, unknown method (only GET/POST/PUT/DELETE allowed): " + method,
view.getEntityReference()+"", HttpServletResponse.SC_BAD_REQUEST);
}
// check that the request is valid (delete requires an entity id)
if ( EntityView.VIEW_DELETE.equals(view.getViewKey())
&& view.getEntityReference().getId() == null) {
throw new EntityException("Unable to handle entity ("+view.getEntityReference()+") delete request without entity id, url="
+ view.getOriginalEntityUrl(),
view.getEntityReference()+"", HttpServletResponse.SC_BAD_REQUEST);
}
}
return output;
}
/**
* This method will correctly extract the format constant from a request
* (extension first and then Accepts header) and then set it in the response
* as the correct return type, if none is found then the default will be used
* @param req the Servlet request
* @param res the Servlet response
* @param defaultFormat (OPTIONAL) if this is set then it will be the default format assigned when none can be found,
* otherwise the default format is {@link Formats#HTML}
* @return the extracted format (will never be null), e.g {@link Formats#XML}
*/
@SuppressWarnings("unchecked")
public static String findAndHandleFormat(HttpServletRequest req, HttpServletResponse res, String defaultFormat) {
if (defaultFormat == null) {
defaultFormat = Formats.HTML;
}
String path = req.getPathInfo();
String format = TemplateParseUtil.findExtension(path)[2];
if (format == null) {
// try to get it from the Accept header
for (Enumeration<String> enumHeader = req.getHeaderNames(); enumHeader.hasMoreElements();) {
String headerName = enumHeader.nextElement();
if ("accept".equalsIgnoreCase(headerName)) {
ArrayList<String> accepts = new ArrayList<String>();
for (Enumeration<String> enumAccepts = req.getHeaders(headerName); enumAccepts.hasMoreElements();) {
String mimeType = enumAccepts.nextElement();
if (mimeType == null) {
continue;
}
mimeType = mimeType.trim();
// trim out the optional stuff
int pos = mimeType.indexOf(';');
if (pos > 0) {
mimeType = mimeType.substring(0, pos).trim();
}
accepts.add( mimeType );
}
// sort the list to longest first and shortest last
Collections.sort(accepts, new ShortestStringLastComparator());
for (String mimeType : accepts) {
String f = mimeTypeToFormat.get(mimeType);
if (f != null) {
format = f;
break; // FOUND A MIME MATCH
}
}
break; // STOP CHECKING HEADERS
}
}
}
if (format == null || "".equals(format)) {
// set the default value
format = defaultFormat;
}
RequestUtils.setResponseEncoding(format, res);
return format;
}
/**
* Comparator which puts the longest strings first and the shortest last
*/
public static class ShortestStringLastComparator implements Comparator<String>, Serializable {
public static final long serialVersionUID = 11L;
public int compare(String o1, String o2) {
int compare = 0;
if (o1 == null && o2 == null) {
compare = 0;
} else if (o1 == null) {
compare = 1;
} else if (o2 == null) {
compare = -1;
} else {
compare = o2.length() - o1.length();
}
return compare;
}
}
// put the keys which should be ignored in this array which will be placed in a set and ignored
public static String[] ignoreForSearch = new String[] {
EntityRequestHandler.COMPENSATE_METHOD,
"queryString",
"pathInfo",
"method",
RequestStorage.ReservedKeys._locale.name(),
RequestStorage.ReservedKeys._requestActive.name(),
RequestStorage.ReservedKeys._requestEntityReference.name(),
RequestStorage.ReservedKeys._requestOrigin.name(),
"entity-format"
};
private static HashSet<String> ignoreSet = null;
private static synchronized HashSet<String> getIgnoreSet() {
if (ignoreSet == null) {
// load the array into a set for easier and faster checks
ignoreSet = new HashSet<String>();
for (int i = 0; i < ignoreForSearch.length; i++) {
ignoreSet.add(ignoreForSearch[i]);
}
}
return ignoreSet;
}
/**
* This looks at request parameters and returns anything it finds in the
* request parameters that can be put into the search,
* supports the page params and sorting params
*
* @param params the request params from a request (do not include headers)
* @return a search filter object
*/
public static Search makeSearchFromRequestParams(Map<String, Object> params) {
Search search = new Search();
int page = -1;
int limit = -1;
try {
if (params != null) {
for (Entry<String, Object> entry : params.entrySet()) {
String key = entry.getKey();
// filter out certain keys
if (getIgnoreSet().contains(key)) {
continue; // skip this key
}
Object value = entry.getValue();
if (value == null) {
// in theory this should not happen
continue;
} else if (value.getClass().isArray()) {
// use the value as is
} else {
// get paging values out if possible
if ("_limit".equals(key)
|| "_perpage".equals(key)
|| "perpage".equals(key)
|| "count".equals(key)
|| "itemsPerPage".equals(key)) {
try {
limit = Integer.valueOf(value.toString()).intValue();
search.setLimit(limit);
} catch (NumberFormatException e) {
System.out.println("WARN Invalid non-number passed in for _limit/_perpage param: " + value + ":" + e);
}
continue;
} else if ("_start".equals(key)
|| "startIndex".equals(key)) {
try {
int start = Integer.valueOf(value.toString()).intValue();
search.setStart(start);
} catch (NumberFormatException e) {
System.out.println("WARN Invalid non-number passed in for '_start' param: " + value + ":" + e);
}
continue;
} else if ("_page".equals(key)
|| "page".equals(key)
|| "startPage".equals(key)) {
try {
page = Integer.valueOf(value.toString()).intValue();
} catch (NumberFormatException e) {
System.out.println("WARN Invalid non-number passed in for '_page' param: " + value + ":" + e);
}
continue;
} else if ("_order".equals(key)
|| "_sort".equals(key)
|| "sort".equals(key)) {
if (value != null) {
String val = value.toString();
String[] sortBy = new String[] {val};
if (val.indexOf(',') > 0) {
// multiple sort params
sortBy = val.split(",");
}
try {
for (int i = 0; i < sortBy.length; i++) {
String sortItem = sortBy[i].trim();
if (sortItem.endsWith("_reverse")) {
search.addOrder( new Order(sortItem.substring(0, sortItem.length()-8), false) );
} else if (sortItem.endsWith("_desc")) {
search.addOrder( new Order(sortItem.substring(0, sortItem.length()-5), false) );
} else if (sortItem.endsWith("_asc")) {
search.addOrder( new Order(sortItem.substring(0, sortItem.length()-4)) );
} else {
search.addOrder( new Order(sortItem) );
}
}
} catch (RuntimeException e) {
System.out.println("WARN Failed while getting the sort/order param: " + val + ":" + e);
}
}
continue;
} else if ("_searchTerms".equals(key)
|| "searchTerms".equals(key)) {
// indicates a space delimited list of search terms
if (value != null) {
String val = value.toString();
String[] terms = val.split(" ");
search.addRestriction( new Restriction("searchTerms", terms) );
}
continue;
}
}
search.addRestriction( new Restriction(key, value) );
}
}
} catch (Exception e) {
// failed to translate the request to a search, not really much to do here
System.out.println("WARN Could not translate entity request into search params: " + e.getMessage() + ":" + e);
}
// translate page into start/limit
if (page > 0) {
if (limit <= -1) {
limit = 10; // set to a default value
search.setLimit(limit);
System.out.println("WARN page is set without a limit per page, setting per page limit to default value of 10");
}
search.setStart( (page-1) * limit );
}
return search;
}
/**
* This will set the response mime type correctly based on the format constant,
* also sets the response encoding to UTF_8
* @param format the format constant, example {@link Formats#XML}
* @param res the current outgoing response
*/
public static void setResponseEncoding(String format, HttpServletResponse res) {
String encoding = Formats.TXT_MIME_TYPE;
if (format != null) {
String mimeType = formatToMimeType.get(format);
if (mimeType != null) {
encoding = mimeType;
}
}
res.setContentType(encoding);
res.setCharacterEncoding(Formats.UTF_8);
}
/**
* This finds the correct servlet path or returns the default one,
* will not return "" or null
* @param req the incoming request
* @return the servlet context path (/ + servletName)
*/
public static String getServletContext(HttpServletRequest req) {
String context = null;
if (req != null) {
context = req.getContextPath();
if ("".equals(context)) {
context = req.getServletPath();
}
}
if (context == null || "".equals(context)) {
context = EntityView.DIRECT_PREFIX;
}
return context;
}
}