/*
* 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.portal.impl;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpSession;
import net.paoding.rose.web.portal.Window;
import net.paoding.rose.web.portal.util.Enumerator;
/**
* 封装窗口请求，使每个窗口都有自己的独立属性空间，同时又能共享共同的portal请求对象的属性
*
* @author 王志亮 [qieqie.wang@gmail.com]
*
*/
class WindowRequest extends HttpServletRequestWrapper {
private static final String HEAER_IF_MODIFIED_SINCE = "If-Modified-Since";
private static final String HEAER_IF_NONE_MATHC = "If-None-Match";
private final Window window;
/**
* 那些属性是这个窗口所不要的，在此标志
*/
private Set<String> deleteAttributes;
/** 锁 */
private Object mutex = this;
public WindowRequest(Window window, HttpServletRequest request) {
super(request);
this.window = window;
}
// ------------------------------------------------- ServletRequest Methods
/**
* 返回这个窗口的私有属性或portal主控请求对象的共同属性
*
* @param name Name of the attribute to retrieve
*/
public Object getAttribute(String name) {
Object value = null;
synchronized (mutex) {
if (deleteAttributes != null && deleteAttributes.contains(name)) {
return null;
}
value = window.get(name);
if (value == null) {
value = super.getAttribute(name);
}
}
return value;
}
@Override
public String getHeader(String name) {
if (isDisabledHeader(name)) {
return null;
}
return super.getHeader(name);
}
@SuppressWarnings("unchecked")
@Override
public Enumeration getHeaders(String name) {
if (isDisabledHeader(name)) {
return null;
}
return super.getHeaders(name);
}
/**
* 判断指定header是否被屏蔽掉了。 为了window能够正确执行，可能会屏蔽掉一些header，
* 例如，通过屏蔽If-Modified-Since和If-None-Match来解决 Window返回304的问题。
*
* @param headerName
* @return
*/
private boolean isDisabledHeader(String headerName) {
return HEAER_IF_MODIFIED_SINCE.equals(headerName) || HEAER_IF_NONE_MATHC.equals(headerName);
}
/**
* 返回这个窗口的私有属性名加portal主控请求对象共同属性的属性名
*/
@SuppressWarnings("unchecked")
public Enumeration getAttributeNames() {
HashSet<String> keys;
synchronized (mutex) {
keys = new HashSet<String>(window.getAttributes().keySet());
Enumeration<String> names = super.getAttributeNames();
while (names.hasMoreElements()) {
String name = (String) names.nextElement();
if (deleteAttributes == null || !deleteAttributes.contains(name)) {
keys.add(name);
}
}
}
return new Enumerator(keys);
}
/**
* 实际删除私有属性，如果是窗口共有的portal属性，只是在本窗口中做删除标志，其他窗口还能正常获取
*
* @param name Name of the attribute to remove
*/
public void removeAttribute(String name) {
if (name == null) {
throw new NullPointerException("don't set a NULL named attribute");
}
synchronized (mutex) {
window.remove(name);
if (deleteAttributes == null) {
deleteAttributes = new HashSet<String>(4);
deleteAttributes.add(name);
}
}
}
/**
*
* 设置窗口私有属性
*
* @param name Name of the attribute to set
* @param value Value of the attribute to set
*/
public void setAttribute(String name, Object value) {
if (name == null) {
throw new NullPointerException("don't set a NULL named attribute");
}
if (value == null) {
removeAttribute(name);
return;
}
synchronized (mutex) {
window.set(name, value);
if (deleteAttributes != null) {
deleteAttributes.remove(name);
}
}
}
public Map<String, Object> getPrivateAttributes() {
return window.getAttributes();
}
@Override
public HttpSession getSession() {
return getSession(true);
}
@Override
public HttpSession getSession(boolean create) {
HttpSession session = super.getSession(false);
if (session != null) {
return session;
}
if (create) {
if (window.getContainer().getInvocation().getResponse().isCommitted()) {
session = new SessionAfterCommitted(new IllegalStateException(
"Cannot create a session after the response has been committed"));
} else {
try {
session = super.getSession(true);
} catch (IllegalStateException e) {
session = new SessionAfterCommitted(e);
}
}
}
return session;
}
}