org.alfresco.catalina.valve

Class AVMUrlValve

java.lang.Object

org.apache.catalina.valves.ValveBase

org.alfresco.catalina.valve.AVMUrlValve

All Implemented Interfaces:

MBeanRegistration, org.apache.catalina.Contained, org.apache.catalina.Lifecycle, org.apache.catalina.Valve

public class AVMUrlValve
extends org.apache.catalina.valves.ValveBase
implements org.apache.catalina.Lifecycle

Rewrites requests to make them easy for Alfresco to virtualize.

     RFCs regarding hostnames & fully qualified domain names (FQDN):
     608, 810, 952, 1035, and 1123.   The following PCRE-style
     regex defines a valid label within a FQDN:

          ^[a-zA-Z0-9][a-zA-Z0-9-]{0,61}[a-zA-Z0-9]$

     Less formally:

          o  Case insensitive
          o  First/last character:  alphanumeric
          o  Interior characters:   alphanumeric plus hyphen
          o  Minimum length:        2  characters
          o  Maximum length:        63 characters

     The minimum 2-char length does not seem to be enforced by
     nameservers/resovlers in the real world.  For example, djbdns
     uses nameserver names like:   a.ns.example.com,  b.ns.example.com, etc.

     The FQDN (fully qualified domain name) is the following constraints:

          o  Maximum 255 characters          (e.g.: www.foo.example.com)
          o  Must contain at least one alpha (i.e.: [a-z])

     Thus, the following FQDN would be illegal because it contains
     a hostname label that is too long (64 > 63):

        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.com

     But the following FQDN would be ok because no host label is > 63 chars,
     and the total length is less than 255 chars:

     moo.cow.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.com

     Ultimately, I18N-encoded domain names will be supported via the IDNA 
     (Internationalizing Domain Names In Applications) standard.   
     IDNA encodes host labels that would normally contain I18N chars using 
     a "xn--" prefix.  Apps present IDNA URLs in decoded form, but only
     the "traditional" DNS characters ever go over the wire.  For details,
     see RFC-3490 (http://www.ietf.org/rfc/rfc3490.txt)
     and RFC-3492 (http://www.ietf.org/rfc/rfc3492.txt).

     The encoding scheme used for virtualization has been designed to
     be IDNA-friendly; when GUI support becomes available, no changes
     will be needed as far as the virtualization logic is concnered.

 

Field Summary

Fields

Modifier and Type	Field and Description
protected static ThreadLocal	AVMUrlValve_invoked_
protected org.apache.catalina.util.LifecycleSupport	lifecycle Lifecycle event support.
protected static org.apache.commons.logging.Log	log

Fields inherited from class org.apache.catalina.valves.ValveBase

container, containerLog, controller, domain, info, mserver, next, oname, sm

Fields inherited from interface org.apache.catalina.Lifecycle

AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, DESTROY_EVENT, INIT_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

Constructors

Constructor and Description
AVMUrlValve()

Method Summary

Methods

Modifier and Type	Method and Description
void	addLifecycleListener(org.apache.catalina.LifecycleListener listener)
org.apache.catalina.LifecycleListener[]	findLifecycleListeners()
static String	GetContextNameFromStoreName(int version, String storeName, String webappName) Transforms a version (e.g.: -1), a storeName (e.g.: "mysite--alice"), and a webappName (e.g.: "ROOT") into a virtualized context name (e.g.: "/$-1$mysite--alice$ROOT")
static String	GetContextNameFromStorePath(int version, String storePath) Transforms a version (e.g.: -1), and a storePath (e.g.: "mysite--alice:/www/avm_webapps/ROOT") into a virtualized context name (e.g.: "/$-1$mysite--alice$ROOT").
void	invoke(org.apache.catalina.connector.Request request, org.apache.catalina.connector.Response response) This method is called by Tomcat's pipeline mechanism on every new request.
void	removeLifecycleListener(org.apache.catalina.LifecycleListener listener)
void	start()
void	stop()
static String	unMangleAVMuri(String uri) Returns an un AVM-mangled version of uri.

Methods inherited from class org.apache.catalina.valves.ValveBase

backgroundProcess, createObjectName, getContainer, getContainerName, getController, getDomain, getInfo, getNext, getObjectName, getParentName, postDeregister, postRegister, preDeregister, preRegister, setContainer, setController, setNext, setObjectName, toString

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static org.apache.commons.logging.Log log

lifecycle

protected org.apache.catalina.util.LifecycleSupport lifecycle

Lifecycle event support.

AVMUrlValve_invoked_

protected static ThreadLocal AVMUrlValve_invoked_

Constructor Detail

AVMUrlValve

public AVMUrlValve()

Method Detail

addLifecycleListener

public void addLifecycleListener(org.apache.catalina.LifecycleListener listener)

Specified by:

addLifecycleListener in interface org.apache.catalina.Lifecycle

findLifecycleListeners

public org.apache.catalina.LifecycleListener[] findLifecycleListeners()

Specified by:

findLifecycleListeners in interface org.apache.catalina.Lifecycle

removeLifecycleListener

public void removeLifecycleListener(org.apache.catalina.LifecycleListener listener)

Specified by:

removeLifecycleListener in interface org.apache.catalina.Lifecycle

start

public void start()
           throws org.apache.catalina.LifecycleException

Specified by:

start in interface org.apache.catalina.Lifecycle

Throws:

org.apache.catalina.LifecycleException

stop

public void stop()
          throws org.apache.catalina.LifecycleException

Specified by:

stop in interface org.apache.catalina.Lifecycle

Throws:

org.apache.catalina.LifecycleException

GetContextNameFromStoreName

public static String GetContextNameFromStoreName(int version,
                                 String storeName,
                                 String webappName)

Transforms a version (e.g.: -1), a storeName (e.g.: "mysite--alice"), and a webappName (e.g.: "ROOT") into a virtualized context name (e.g.: "/$-1$mysite--alice$ROOT")

GetContextNameFromStorePath

public static String GetContextNameFromStorePath(int version,
                                 String storePath)

Transforms a version (e.g.: -1), and a storePath (e.g.: "mysite--alice:/www/avm_webapps/ROOT") into a virtualized context name (e.g.: "/$-1$mysite--alice$ROOT"). On failure, null is returned.

invoke

public void invoke(org.apache.catalina.connector.Request request,
          org.apache.catalina.connector.Response response)
            throws IOException,
                   javax.servlet.ServletException

This method is called by Tomcat's pipeline mechanism on every new request. Within

           $TOMCAT_HOME/conf/server.xml
 

this valve is directly contained by the <Engine> node, thereby enabling it to view every request to localhost prior to any other part of the servlet engine. For example:

   <Engine name="Catalina" defaultHost="localhost">
         <Valve className="org.alfresco.catalina.valve.AVMUrlValve"/>
         ...
   </Engine>
 

Specified by:

invoke in interface org.apache.catalina.Valve

Specified by:

invoke in class org.apache.catalina.valves.ValveBase

Parameters:

request - The request, prior to the servlet engine seeing it.

response - The reqponse, after the servlet engine is done with it.

Throws:

IOException

javax.servlet.ServletException

unMangleAVMuri

public static String unMangleAVMuri(String uri)

Returns an un AVM-mangled version of uri.

Example of AVM-mangled subreq URI:

     /$-1$store-1$servlets-examples/servlet/RequestInfoExample
   

After unmangling:

     /servlets-examples/servlet/RequestInfoExample
   

If this were for a non-HEAD version (e.g.: '4'), the mangled subrequest URI might look like this:

     /$4$store-1$servlets-examples/servlet/RequestInfoExample
   

The URI would still contain the webapp name after unmangling:

     /servlets-examples/servlet/RequestInfoExample
   

However, if this is the ROOT webapp, because the context path is "", a mangle name like this:

     /$-1$store-1$ROOT/servlet/RequestInfoExample
  

becomes:

     /servlet/RequestInfoExample