org.apache.jasper.compiler

Class 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.

Authors:
Pierre Delisle
Jan Luehe

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(ServletContext ctxt)
TldLocationsCache(ServletContext ctxt, boolean redeployMode)
Constructor.

Method Summary

String[]
getLocation(String uri)
Gets the 'location' of the TLD associated with the given taglib 'uri'.
static void
setNoTldJars(String jarNames)
Sets the list of JARs that are known not to contain any TLDs.
static int
uriType(String uri)
Returns the type of a URI: ABS_URI ROOT_REL_URI NOROOT_REL_URI

Field Details

ABS_URI

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

Field Value:
0


NOROOT_REL_URI

public static final int NOROOT_REL_URI

Field Value:
2


ROOT_REL_URI

public static final int ROOT_REL_URI

Field Value:
1

Constructor Details

TldLocationsCache

public TldLocationsCache(ServletContext ctxt)


TldLocationsCache

public TldLocationsCache(ServletContext ctxt,
                         boolean redeployMode)
Constructor.

Parameters:
ctxt - the servlet context of the web application in which Jasper is running
redeployMode - if true, then the compiler will allow redeploying a tag library from the same jar, at the expense of slowing down the server a bit. Note that this may only work on JDK 1.3.1_01a and later, because of JDK bug 4211817 fixed in this release. If redeployMode is false, a faster but less capable mode will be used.

Method Details

getLocation

public String[] getLocation(String uri)
            throws JasperException
Gets the 'location' of the TLD associated with the given taglib 'uri'. Returns null if the uri is not associated with any tag library 'exposed' in the web application. A tag library is 'exposed' either explicitly in web.xml or implicitly via the uri tag in the TLD of a taglib deployed in a jar file (WEB-INF/lib).

Parameters:
uri - The taglib uri

Returns:
An array of two Strings: The first element denotes the real path to the TLD. If the path to the TLD points to a jar file, then the second element denotes the name of the TLD entry in the jar file. Returns null if the uri is not associated with any tag library 'exposed' in the web application.


setNoTldJars

public static void setNoTldJars(String jarNames)
Sets the list of JARs that are known not to contain any TLDs.

Parameters:
jarNames - List of comma-separated names of JAR files that are known not to contain any TLDs


uriType

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


Copyright B) 2000 Apache Software Foundation. All Rights Reserved.