* Unlike regular servlets, DSpace servlets should override the
* doDSGet and doDSPost methods, which provide a
* DSpace context to work with, and handle the common exceptions
* SQLException and AuthorizeException.
* doGet and doPost should be overridden only in
* special circumstances.
*
* Note that if all goes well, the context object passed in to
* doDSGet and doDSPut must be completed
* after a JSP has been displayed, but before the
* method returns. If an error occurs (an exception is thrown, or the context is
* not completed) the context is aborted after doDSGet or
* doDSPut return.
*
* @see org.dspace.core.Context
*
* @author Robert Tansley
* @version $Revision$
*/
public class DSpaceServlet extends HttpServlet
{
/*
* Because the error handling is indentical for GET and POST requests, to
* make things easier, doGet and doPost are folded into one method which
* then "re-separates" to GET and POST. We do not override "service" since
* we wish to allow doGet and doPost to be overridden if necessary (for
* example, by lightweight servlets that do not need a DSpace context
* object).
*/
/** log4j category */
private static final Logger log = Logger.getLogger(DSpaceServlet.class);
protected transient AuthorizeService authorizeService
= AuthorizeServiceFactory.getInstance().getAuthorizeService();
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
processRequest(request, response);
}
@Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
processRequest(request, response);
}
/**
* Process an incoming request
*
* @param request
* the request object
* @param response
* the response object
*/
private void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
Context context = null;
// set all incoming encoding to UTF-8
request.setCharacterEncoding("UTF-8");
// Get the URL from the request immediately, since forwarding
// loses that information
UIUtil.storeOriginalURL(request);
try
{
// Obtain a context - either create one, or get the one created by
// an authentication filter
context = UIUtil.obtainContext(request);
// Are we resuming a previous request that was interrupted for
// authentication?
request = Authenticate.getRealRequest(request);
if (log.isDebugEnabled())
{
log.debug(LogManager.getHeader(context, "http_request", UIUtil
.getRequestLogInfo(request)));
}
// Invoke the servlet code
if (request.getMethod().equals("POST"))
{
doDSPost(context, request, response);
}
else
{
doDSGet(context, request, response);
}
}
catch (SQLException se)
{
// For database errors, we log the exception and show a suitably
// apologetic error
log.warn(LogManager.getHeader(context, "database_error", se
.toString()), se);
// Also email an alert
UIUtil.sendAlert(request, se);
abortContext(context);
JSPManager.showInternalError(request, response);
}
catch (AuthorizeException ae)
{
/*
* If no user is logged in, we will start authentication, since if
* they authenticate, they might be allowed to do what they tried to
* do. If someone IS logged in, and we got this exception, we know
* they tried to do something they aren't allowed to, so we display
* an error in that case.
*/
if (context.getCurrentUser() != null ||
Authenticate.startAuthentication(context, request, response))
{
// FIXME: Log the right info?
// Log the error
log.info(LogManager.getHeader(context, "authorize_error", ae
.toString()));
JSPManager.showAuthorizeError(request, response, ae);
}
abortContext(context);
}
catch (IOException ioe)
{
/*
* If a an IOException occurs (e.g. if the client interrupted a download),
* just log a simple warning without stacktrace.
*/
log.warn(LogManager.getHeader(context, "io_error", ioe.toString()));
abortContext(context);
}
catch (Exception e)
{
log.warn(LogManager.getHeader(context, "general_jspui_error", e
.toString()), e);
abortContext(context);
JSPManager.showInternalError(request, response);
}
finally
{
// Abort the context if it's still valid
if ((context != null) && context.isValid())
{
//Always commit at the end
try {
context.complete();
} catch (SQLException e) {
log.error(e.getMessage(), e);
JSPManager.showInternalError(request, response);
}
}
}
}
private void abortContext(Context context) {
if(context != null && context.isValid())
{
context.abort();
}
}
/**
* Process an incoming HTTP GET. If an exception is thrown, or for some
* other reason the passed in context is not completed, it will be aborted
* and any changes made by this method discarded when this method returns.
*
* @param context
* a DSpace Context object
* @param request
* the HTTP request
* @param response
* the HTTP response
*
* @throws SQLException
* if a database error occurs
* @throws AuthorizeException
* if some authorization error occurs
*/
protected void doDSGet(Context context, HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException,
SQLException, AuthorizeException
{
// If this is not overridden, we invoke the raw HttpServlet "doGet" to
// indicate that GET is not supported by this servlet.
super.doGet(request, response);
}
/**
* Process an incoming HTTP POST. If an exception is thrown, or for some
* other reason the passed in context is not completed, it will be aborted
* and any changes made by this method discarded when this method returns.
*
* @param context
* a DSpace Context object
* @param request
* the HTTP request
* @param response
* the HTTP response
*
* @throws SQLException
* if a database error occurs
* @throws AuthorizeException
* if some authorization error occurs
*/
protected void doDSPost(Context context, HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException,
SQLException, AuthorizeException
{
// If this is not overridden, we invoke the raw HttpServlet "doGet" to
// indicate that POST is not supported by this servlet.
super.doGet(request, response);
}
}