org.apache.jasper.compiler
Class TldLocationsCache

java.lang.Object
  |
  +--org.apache.jasper.compiler.TldLocationsCache

public class TldLocationsCache
extends java.lang.Object

A container for all tag libraries that are defined "globally" for the web application. Tag Libraries can be defined globally in one of two ways: 1. Via elements in web.xml: the uri and location of the tag-library are specified in the element. 2. Via packaged jar files that contain .tld files within the META-INF directory, or some subdirectory of it. The taglib is 'global' if it has the element defined. A mapping between the taglib URI and its associated TaglibraryInfoImpl is maintained in this container. Actually, that's what we'd like to do. However, because of the way the classes TagLibraryInfo and TagInfo have been defined, it is not currently possible to share an instance of TagLibraryInfo across page invocations. A bug has been submitted to the spec lead. In the mean time, all we do is save the 'location' where the TLD associated with a taglib URI can be found. When a JSP page has a taglib directive, the mappings in this container are first searched (see method getLocation()). If a mapping is found, then the location of the TLD is returned. If no mapping is found, then the uri specified in the taglib directive is to be interpreted as the location for the TLD of this tag library.

Author:
Pierre Delisle

Field Summary
static int ABS_URI
          The types of URI one may specify for a tag library
static int NOROOT_REL_URI
           
static int ROOT_REL_URI
           
 
Constructor Summary
TldLocationsCache(javax.servlet.ServletContext ctxt)
           
 
Method Summary
 java.lang.String[] getLocation(java.lang.String uri)
          Get the 'location' of the TLD associated with a given taglib 'uri'.
static int uriType(java.lang.String uri)
          Returns the type of a URI: ABS_URI ROOT_REL_URI NOROOT_REL_URI
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

ABS_URI

public static final int ABS_URI
The types of URI one may specify for a tag library

See Also:
Constant Field Values

ROOT_REL_URI

public static final int ROOT_REL_URI
See Also:
Constant Field Values

NOROOT_REL_URI

public static final int NOROOT_REL_URI
See Also:
Constant Field Values
Constructor Detail

TldLocationsCache

public TldLocationsCache(javax.servlet.ServletContext ctxt)
Method Detail

getLocation

public java.lang.String[] getLocation(java.lang.String uri)
                               throws JasperException
Get the 'location' of the TLD associated with a given taglib 'uri'.

Returns:
An array of two Strings. The first one is real path to the TLD. If the path to the TLD points to a jar file, then the second string is the name of the entry for the TLD in the jar file. Returns null if the uri is not associated to a tag library 'exposed' in the web application. A tag library is 'exposed' either explicitely in web.xml or implicitely via the uri tag in the TLD of a taglib deployed in a jar file (WEB-INF/lib).
JasperException

uriType

public static int uriType(java.lang.String uri)
Returns the type of a URI: ABS_URI ROOT_REL_URI NOROOT_REL_URI



Copyright 2000 Apache Software Foundation. All Rights Reserved.