/*
* Copyright 2007-2009 the original author or authors.
*
* 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 net.paoding.rose.web.var;
import net.paoding.rose.util.Base64;
import net.paoding.rose.util.PlaceHolderUtils;
import net.paoding.rose.web.Invocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author 王志亮 [qieqie.wang@gmail.com]
*
*/
public class FlashImpl implements Flash {
private static final String DELIM = "___";
private static final String cookiePrefix = DELIM + "flashMessage" + DELIM;
private static Log logger = LogFactory.getLog(FlashImpl.class);
private Map<String, String> last = Collections.emptyMap();
private boolean lastRead = false;
private Map<String, String> next = Collections.emptyMap();
private static final Base64 base64 = new Base64();
private Invocation invocation;
public FlashImpl(Invocation invocation) {
this.invocation = invocation;
}
protected synchronized void readLastMessages() {
if (lastRead) {
return;
}
lastRead = true;
if (logger.isDebugEnabled()) {
logger.debug("readLastMessages");
}
Cookie[] cookies = invocation.getRequest().getCookies();
for (int i = 0; cookies != null && i < cookies.length; i++) {
if (logger.isDebugEnabled()) {
logger.debug("cookie " + cookies[i].getName() + "=" + cookies[i].getValue()
+ "; age=" + cookies[i].getMaxAge());
}
if (cookies[i].getValue() == null) {
if (logger.isDebugEnabled()) {
logger.debug("ignore cookie: " + cookies[i].getName());
}
continue;
}
if (cookies[i].getName().startsWith(cookiePrefix)) {
StringTokenizer st = new StringTokenizer(cookies[i].getName(), DELIM);
String[] splits = new String[st.countTokens()];
for (int j = 0; j < splits.length; j++) {
splits[j] = st.nextToken();
}
if (splits.length < 2) {
if (logger.isInfoEnabled()) {
logger.info("ignore flash cookie: " + cookies[i].getName());
}
continue;
}
String name = splits[1];
String cookieValue = cookies[i].getValue();
String flashMessage;
if (cookieValue.length() == 0) {
flashMessage = "";
} else {
try {
flashMessage = new String(base64.decodeFromString(cookieValue), "UTF-8");
} catch (Exception e) {
logger.error("failed to decode '" + cookieValue + "' as"
+ " a base64 string", e);
flashMessage = cookieValue;
}
}
if (last.size() == 0) {
last = new LinkedHashMap<String, String>();
}
this.last.put(name, flashMessage);
Cookie cookie = new Cookie(cookies[i].getName(), "");
cookie.setPath("/");
cookie.setMaxAge(0);
invocation.getResponse().addCookie(cookie);
if (logger.isDebugEnabled()) {
logger.debug("found flash message:" + name + "=" + flashMessage);
}
}
}
}
public void writeNewMessages() {
if (logger.isDebugEnabled()) {
logger.debug("writeNextMessages");
}
HttpServletResponse response = invocation.getResponse();
List<String> responseCookies = null;
for (Map.Entry<String, String> entry : next.entrySet()) {
if (responseCookies == null) {
responseCookies = new ArrayList<String>(next.size());
}
String cookieValue;
if (entry.getValue() == null) {
cookieValue = "";
} else {
try {
cookieValue = base64.encodeToString(entry.getValue().getBytes("UTF-8"));
} catch (UnsupportedEncodingException e) {
throw new Error(e);
}
}
Cookie cookie = new Cookie(cookiePrefix + entry.getKey(), cookieValue);
cookie.setPath("/");
// cookie.setMaxAge(1);
response.addCookie(cookie);
responseCookies.add(cookie.getName());
if (logger.isDebugEnabled()) {
logger.debug("write flash cookie:" + cookie.getName() + "=" + cookie.getValue());
}
}
for (Map.Entry<String, String> entry : last.entrySet()) {
if (responseCookies == null || !responseCookies.contains(entry.getKey())) {
Cookie c = new Cookie(entry.getKey(), null);
c.setMaxAge(0);
c.setPath("/");
response.addCookie(c);
if (logger.isDebugEnabled()) {
logger.debug("delete flash cookie:" + c.getName() + "=" + c.getValue());
}
}
}
}
@Override
public boolean contains(String name) {
readLastMessages();
return last.containsKey(name);
}
@Override
public String get(String name) {
readLastMessages();
return last.get(name);
}
@Override
public Collection<String> getMessageNames() {
readLastMessages();
return last.keySet();
}
@Override
public Map<String, String> getMessages() {
return Collections.unmodifiableMap(last);
}
@Override
public Flash add(String name, String flashMessage) {
Assert.notNull(name, "Flash attribute name must not be null");
flashMessage = PlaceHolderUtils.resolve(flashMessage, invocation);
if (next.size() == 0) {
next = new LinkedHashMap<String, String>(2);
}
next.put(name, flashMessage);
if (logger.isDebugEnabled()) {
logger.debug("add flashMessage: " + name + "=" + flashMessage);
}
return this;
}
@Override
public Collection<String> getNewMessageNames() {
return next.keySet();
}
@Override
public Map<String, String> getNewMessages() {
return Collections.unmodifiableMap(next);
}
}