org.directwebremoting.WebContext Maven / Gradle / Ivy
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.
* WebContext is only available from a DWR thread. If you need to access web
* data from a non-DWR thread, use the superclass, {@link ServerContext}.
* @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.
* If the DWR thread that gave rise to this {@link WebContext} is as a
* result of a JSON call, this method will throw an UnsupportedOperationException
* @return A browser object for this user
* @throws UnsupportedOperationException If this is part of a JSON call
*/
ScriptSession getScriptSession() throws UnsupportedOperationException;
/**
* Returns the partial-URL of the page from which the current thread
* originated.
* This string starts from (and includes) the application's context path,
* and therefore excludes the scheme, host, and port of the URL.
* If the URL has a query string (starting with and including a '?'
* character) and/or an in-page location (starting with and including a '#'
* character), these portions will be excluded. If the URL has a session
* identifier, i.e. via an application server's URL-rewriting behavior, this
* may not necessarily be excluded. e.g. Tomcat's default is to use
* ";jsessionid=123...".
* NOTE: this means that DWR will consider a session-appended URL to be
* distinct from a non-session-appended URL.
* @see org.directwebremoting.extend.PageNormalizer for details on how pages
* are converted from external form to this form.
* @throws UnsupportedOperationException If this is part of a JSON call
* @return ...
*/
String getCurrentPage() throws UnsupportedOperationException;
/**
* 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;
}