Package org.apache.jasper.runtime
Class TldScanner
java.lang.Object
org.apache.jasper.runtime.TldScanner
- All Implemented Interfaces:
javax.servlet.ServletContainerInitializer
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.
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Nested Class Summary
Nested Classes -
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
The types of URI one may specify for a tag libraryprivate boolean
private javax.servlet.ServletContext
private boolean
private static final String
private static final String
private static final String
private boolean
private static final String
private static Map
<String, TldScanner.TldInfo[]> private Map
<String, TldScanner.TldInfo[]> A local cache for keeping track which jars have been scanned.private static Logger
The mapping of the 'global' tag library URI (as defined in the tld) to the location (resource path) of the TLD associated with that tag library.static final int
static final int
private boolean
private boolean
private static final String
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Constructor Summary
ConstructorsConstructorDescriptionDefault Constructor.TldScanner
(javax.servlet.ServletContext ctxt, boolean isValidationEnabled) Constructor used in Jasper -
Method Summary
Modifier and TypeMethodDescriptionprivate void
addListener
(TldScanner.TldInfo tldInfo, boolean isLocal) private boolean
addManifestClassPath
(List<String> scannedJars, List<String> newJars, JarURLConnection jconn) String[]
getLocation
(String uri) Gets the 'location' of the TLD associated with the given taglib 'uri'.private void
mapTldLocation
(String resourcePath, TldScanner.TldInfo tldInfo, boolean isLocal) void
private void
processTldsInFileSystem
(String startPath) private void
private void
scanJar
(JarURLConnection conn, List<String> tldNames, boolean isLocal) Scans the given JarURLConnection for TLD files located in META-INF (or a subdirectory of it).private void
scanJars()
private TldScanner.TldInfo
scanTld
(String resourcePath, String entryName, InputStream stream) Scan the given TLD for uri and listeners elements.private void
scanTlds()
Scan the all the tlds accessible in the web app.static int
Returns the type of a URI: ABS_URI ROOT_REL_URI NOROOT_REL_URI
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Field Details
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log
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ABS_URI
public static final int ABS_URIThe types of URI one may specify for a tag library- See Also:
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ROOT_REL_URI
public static final int ROOT_REL_URI- See Also:
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NOROOT_REL_URI
public static final int NOROOT_REL_URI- See Also:
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WEB_XML
- See Also:
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FILE_PROTOCOL
- See Also:
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JAR_FILE_SUFFIX
- See Also:
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systemUris
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systemUrisJsf
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jarTldCache
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EAR_LIB_CLASSLOADER
- See Also:
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IS_STANDALONE_ATTRIBUTE_NAME
- See Also:
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mappings
The mapping of the 'global' tag library URI (as defined in the tld) to the location (resource path) of the TLD associated with that tag library. The location is returned as a String array: [0] The location of the tld file or the jar file that contains the tld [1] If the location is a jar file, this is the location of the tld. -
jarTldCacheLocal
A local cache for keeping track which jars have been scanned. -
ctxt
private javax.servlet.ServletContext ctxt -
isValidationEnabled
private boolean isValidationEnabled -
useMyFaces
private boolean useMyFaces -
scanListeners
private boolean scanListeners -
doneScanning
private boolean doneScanning -
blockExternal
private boolean blockExternal
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Constructor Details
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TldScanner
public TldScanner()Default Constructor. This is only used for implementing ServletContainerInitializer. ServletContext will be supplied in the method onStartUp; -
TldScanner
public TldScanner(javax.servlet.ServletContext ctxt, boolean isValidationEnabled) Constructor used in Jasper
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Method Details
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onStartup
public void onStartup(Set<Class<?>> c, javax.servlet.ServletContext ctxt) throws javax.servlet.ServletException - Specified by:
onStartup
in interfacejavax.servlet.ServletContainerInitializer
- Throws:
javax.servlet.ServletException
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getLocation
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. This method may be called when the scanning is in one of states: 1. Called from jspc script, then a full tld scan is required. 2. The is the first call after servlet initialization, then system jars that are knwon to have tlds but not listeners need to be scanned. 3. Sebsequent calls, no need to scans.
- Throws:
JasperException
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getTldMap
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getTldListenerMap
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uriType
Returns the type of a URI: ABS_URI ROOT_REL_URI NOROOT_REL_URI -
scanTlds
Scan the all the tlds accessible in the web app. For performance reasons, this is done in two stages. At servlet initialization time, we only scan the jar files for listeners. The container passes a list of system jar files that are known to contain tlds with listeners. The rest of the jar files will be scanned when a JSP page with a tld referenced is compiled.- Throws:
JasperException
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processWebDotXml
- Throws:
Exception
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scanJar
private void scanJar(JarURLConnection conn, List<String> tldNames, boolean isLocal) throws JasperException Scans the given JarURLConnection for TLD files located in META-INF (or a subdirectory of it). If the scanning in is done as part of the ServletContextInitializer, the listeners in the tlds in this jar file are added to the servlet context, and for any TLD that has aelement, an implicit map entry is added to the taglib map. - Parameters:
conn
- The JarURLConnection to the JAR file to scantldNames
- the list of tld element to scan. The null value indicates all the tlds in this case.isLocal
- True if the jar file is under WEB-INF false otherwise- Throws:
JasperException
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addListener
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mapTldLocation
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processTldsInFileSystem
- Throws:
JasperException
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scanTld
private TldScanner.TldInfo scanTld(String resourcePath, String entryName, InputStream stream) throws JasperException Scan the given TLD for uri and listeners elements.- Parameters:
resourcePath
- the resource path for the jar file or the tld file.entryName
- If the resource path is a jar file, then the name of the tld file in the jar, else should be null.stream
- The input stream for the tld- Returns:
- The TldInfo for this tld
- Throws:
JasperException
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scanJars
- Throws:
Exception
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addManifestClassPath
private boolean addManifestClassPath(List<String> scannedJars, List<String> newJars, JarURLConnection jconn)
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