org.mycore.frontend.servlets
Class MCRServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.mycore.frontend.servlets.MCRServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

Direct Known Subclasses:

MCRACLEditorServlet_v2, MCRBroadcastingServlet, MCRCheckBase, MCRCheckClassACLServlet, MCRClassExportServlet, MCRClassificationBrowser, MCRClassificationBrowser2, MCRDerivateLinkServlet, MCREditorServlet, MCRFileNodeServlet, MCRFileViewWorkflowServlet, MCRFSMapperServlet, MCRGoogleSitemapServlet, MCRImageServiceServlet, MCRIndexBrowserServlet, MCRIndexServlet, MCRIViewServlet, MCRLinkServlet, MCRListWorkflowServlet, MCRLoginServlet, MCROAIProvider, MCRObjectServlet, MCRRedundancyMapServlet, MCRRemoteFileServlet, MCRSearchServlet, MCRSessionListingServlet, MCRStartClassEditorServlet, MCRStartEditorServlet, MCRStaticXMLFileServlet, MCRUploadServlet, MCRURNResolver, MCRUserAdminGUICommons, MCRUserAjaxServlet, MCRUserServlet, MCRWCMSServlet, MCRWebCLIServlet, MCRZ3950Servlet, MCRZipFileNodeServlet, MCRZipServlet

public class MCRServlet
extends HttpServlet

This is the superclass of all MyCoRe servlets. It provides helper methods for logging and managing the current session data. Part of the code has been taken from MilessServlet.java written by Frank Lützenkirchen.

Version:

$Revision: 15202 $ $Date: 2008-02-06 17:27:24 +0000 (Mi, 06 Feb 2008) $

Author:

Detlev Degenhardt, Frank Lützenkirchen, Thomas Scheffler (yagee)

See Also:

Serialized Form

Field Summary

static String	BASE_URL_ATTRIBUTE
protected static Set<String>	trustedProxies The IP addresses of trusted web proxies

Constructor Summary

MCRServlet()

Method Summary

protected String	buildRedirectURL(String baseURL, Properties parameters) This method builds a URL that can be used to redirect the client browser to another page, thereby including http request parameters.
void	doGet(HttpServletRequest req, HttpServletResponse res)
protected void	doGet(MCRServletJob job)
protected void	doGetPost(MCRServletJob job) This method should be overwritten by other servlets.
void	doPost(HttpServletRequest req, HttpServletResponse res)
protected void	doPost(MCRServletJob job)
protected void	generateActiveLinkErrorpage(HttpServletRequest request, HttpServletResponse response, String msg, MCRActiveLinkException activeLinks)
protected void	generateErrorPage(HttpServletRequest request, HttpServletResponse response, int error, String msg, Exception ex, boolean xmlstyle)
static String	getBaseURL() returns the base URL of the mycore system
protected long	getLastModified(HttpServletRequest request) allows browser to cache requests.
static MCRLayoutService	getLayoutService()
static String	getProperty(HttpServletRequest request, String name)
static String	getRemoteAddr(HttpServletRequest req) Returns the IP address of the client that made the request.
static String	getServletBaseURL() returns the servlet base URL of the mycore system
static MCRSession	getSession(HttpServletRequest req, String servletName)
protected void	handleException(Exception ex) Handles an exception by reporting it and its embedded exception
void	init()
protected static void	initTrustedProxies() Builds a list of trusted proxy IPs from MCR.Request.TrustedProxies.
protected void	render(MCRServletJob job, Exception ex) 2nd phase of doGetPost This method has a seperate transaction and gets the same MCRServletJob from the first phase (think) and any exception that occurs at the first phase.
protected void	reportException(Exception ex) Reports an exception to the log
protected void	think(MCRServletJob job) 1st phase of doGetPost.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BASE_URL_ATTRIBUTE

public static final String BASE_URL_ATTRIBUTE

See Also:

Constant Field Values

trustedProxies

protected static Set<String> trustedProxies

The IP addresses of trusted web proxies

Constructor Detail

MCRServlet

public MCRServlet()

Method Detail

getLayoutService

public static MCRLayoutService getLayoutService()

init

public void init()
          throws ServletException

Overrides:

init in class GenericServlet

Throws:

ServletException

getBaseURL

public static String getBaseURL()

returns the base URL of the mycore system

getServletBaseURL

public static String getServletBaseURL()

returns the servlet base URL of the mycore system

doGet

public void doGet(HttpServletRequest req,
                  HttpServletResponse res)
           throws ServletException,
                  IOException

Overrides:

doGet in class HttpServlet

Throws:

ServletException

IOException

doGet

protected void doGet(MCRServletJob job)
              throws Exception

Throws:

Exception

doPost

public void doPost(HttpServletRequest req,
                   HttpServletResponse res)
            throws ServletException,
                   IOException

Overrides:

doPost in class HttpServlet

Throws:

ServletException

IOException

doPost

protected void doPost(MCRServletJob job)
               throws Exception

Throws:

Exception

getSession

public static MCRSession getSession(HttpServletRequest req,
                                    String servletName)

think

protected void think(MCRServletJob job)
              throws Exception

1st phase of doGetPost. This method has a seperate transaction. Per default id does nothing as a fallback to the old behaviour.

Parameters:

job -

Throws:

Exception

See Also:

render(MCRServletJob, Exception)

render

protected void render(MCRServletJob job,
                      Exception ex)
               throws Exception

2nd phase of doGetPost This method has a seperate transaction and gets the same MCRServletJob from the first phase (think) and any exception that occurs at the first phase. By default this method calls doGetPost(MCRServletJob) as a fallback to the old behaviour.

Parameters:

job - same instance as of think(MCRServlet job)

ex - any exception thrown by think(MCRServletJob) or transaction commit

Throws:

Exception - if render could not handle ex to produce a nice user page

doGetPost

protected void doGetPost(MCRServletJob job)
                  throws Exception

This method should be overwritten by other servlets. As a default response we indicate the HTTP 1.1 status code 501 (Not Implemented).

Throws:

Exception

handleException

protected void handleException(Exception ex)

Handles an exception by reporting it and its embedded exception

reportException

protected void reportException(Exception ex)
                        throws Exception

Reports an exception to the log

Throws:

Exception

generateErrorPage

protected void generateErrorPage(HttpServletRequest request,
                                 HttpServletResponse response,
                                 int error,
                                 String msg,
                                 Exception ex,
                                 boolean xmlstyle)
                          throws IOException

Throws:

IOException

buildRedirectURL

protected String buildRedirectURL(String baseURL,
                                  Properties parameters)

This method builds a URL that can be used to redirect the client browser to another page, thereby including http request parameters. The request parameters will be encoded as http get request.

Parameters:

baseURL - the base url of the target webpage

parameters - the http request parameters

generateActiveLinkErrorpage

protected void generateActiveLinkErrorpage(HttpServletRequest request,
                                           HttpServletResponse response,
                                           String msg,
                                           MCRActiveLinkException activeLinks)
                                    throws IOException

Throws:

IOException

getLastModified

protected long getLastModified(HttpServletRequest request)

allows browser to cache requests. This method is usefull as it allows browsers to cache content that is not changed. Please overwrite this method in every Servlet that depends on "remote" data.

Overrides:

getLastModified in class HttpServlet

getProperty

public static String getProperty(HttpServletRequest request,
                                 String name)

initTrustedProxies

protected static void initTrustedProxies()

Builds a list of trusted proxy IPs from MCR.Request.TrustedProxies. The IP address of the local host is automatically added to this list.

getRemoteAddr

public static String getRemoteAddr(HttpServletRequest req)

Returns the IP address of the client that made the request. When a trusted proxy server was used, e. g. a local Apache mod_proxy in front of Tomcat, the value of the last entry in the HTTP header X_FORWARDED_FOR is returned, otherwise the REMOTE_ADDR is returned. The list of trusted proxy IPs can be configured using the property MCR.Request.TrustedProxies, which is a List of IP addresses separated by blanks and/or comma.