org.directwebremoting.WebContext Maven / Gradle / Ivy
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/*
* Copyright 2005 Joe Walker
*
* 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 org.directwebremoting;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
* Class to enable us to access servlet parameters.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public interface WebContext extends ServerContext
{
/**
* Get the script session that represents the currently viewed page in the
* same way that an HttpSession represents a cookie.
* @return A browser object for this user
*/
ScriptSession getScriptSession();
/**
* What is the URL of the current page.
* This includes 'http://', up to (but not including) '?' or '#'
* @return The URL of the current page
*/
String getCurrentPage();
/**
* Returns the current session associated with this request, or if the
* request does not have a session, creates one.
* @return Returns the http session.
* @see HttpServletRequest#getSession()
*/
HttpSession getSession();
/**
* Returns the current HttpSession associated with this request or, if
* there is no current session and create is true, returns a new session.
* If create is false and the request has no valid HttpSession, this method
* returns null.
* @param create false to return null if there's no current session
* @return the session associated with this request
* @see HttpServletRequest#getSession(boolean)
*/
HttpSession getSession(boolean create);
/**
* Accessor for the http request information.
* @return Returns the request.
*/
HttpServletRequest getHttpServletRequest();
/**
* Accessor for the http response bean.
* You can't use this request to directly reply to the response or to add
* headers or cookies.
* @return Returns the response.
*/
HttpServletResponse getHttpServletResponse();
/**
* An attribute used by {@link WebContext#forwardToString(String)} to inform
* anyone that wants to know that this is a request from DWR.
*/
public static final String ATTRIBUTE_DWR = "org.directwebremoting";
/**
* Forward a request to a given URL and catch the data written to it.
* It is possible to distinguish requests that arrive normally and requests
* that come from a DWR forwardToString() by the presence of a request
* attribute. Before the request is forwarded, DWR will call:
*
* request.setAttribute(WebContext.ATTRIBUTE_DWR, Boolean.TRUE);
*
* @param url The URL to forward to
* @return The text that results from forwarding to the given URL
* @throws IOException if the target resource throws this exception
* @throws ServletException if the target resource throws this exception
* @throws IllegalStateException if the response was already committed
*/
String forwardToString(String url) throws ServletException, IOException;
}