Class TldScanner

  • All Implemented Interfaces:
    javax.servlet.ServletContainerInitializer

    public class TldScanner
    extends java.lang.Object
    implements 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.
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      (package private) static class  TldScanner.TldInfo  
    • Constructor Summary

      Constructors 
      Constructor Description
      TldScanner()
      Default Constructor.
      TldScanner​(javax.servlet.ServletContext ctxt, boolean isValidationEnabled)
      Constructor used in Jasper
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private void addListener​(TldScanner.TldInfo tldInfo, boolean isLocal)  
      private boolean addManifestClassPath​(java.util.List<java.lang.String> scannedJars, java.util.List<java.lang.String> newJars, java.net.JarURLConnection jconn)  
      java.lang.String[] getLocation​(java.lang.String uri)
      Gets the 'location' of the TLD associated with the given taglib 'uri'.
      (package private) java.util.Map<java.net.URI,​java.util.List<java.lang.String>> getTldListenerMap()  
      (package private) java.util.Map<java.net.URI,​java.util.List<java.lang.String>> getTldMap()  
      private void mapTldLocation​(java.lang.String resourcePath, TldScanner.TldInfo tldInfo, boolean isLocal)  
      void onStartup​(java.util.Set<java.lang.Class<?>> c, javax.servlet.ServletContext ctxt)  
      private void processTldsInFileSystem​(java.lang.String startPath)  
      private void processWebDotXml()  
      private void scanJar​(java.net.JarURLConnection conn, java.util.List<java.lang.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​(java.lang.String resourcePath, java.lang.String entryName, java.io.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 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

      • log

        private static java.util.logging.Logger log
      • ABS_URI

        public static final int ABS_URI
        The types of URI one may specify for a tag library
        See Also:
        Constant Field Values
      • systemUris

        private static java.util.HashSet<java.lang.String> systemUris
      • systemUrisJsf

        private static java.util.HashSet<java.lang.String> systemUrisJsf
      • jarTldCache

        private static java.util.Map<java.lang.String,​TldScanner.TldInfo[]> jarTldCache
      • EAR_LIB_CLASSLOADER

        private static final java.lang.String EAR_LIB_CLASSLOADER
        See Also:
        Constant Field Values
      • IS_STANDALONE_ATTRIBUTE_NAME

        private static final java.lang.String IS_STANDALONE_ATTRIBUTE_NAME
        See Also:
        Constant Field Values
      • mappings

        private java.util.HashMap<java.lang.String,​java.lang.String[]> 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

        private java.util.Map<java.lang.String,​TldScanner.TldInfo[]> 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
    • Constructor Detail

      • 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
    • Method Detail

      • onStartup

        public void onStartup​(java.util.Set<java.lang.Class<?>> c,
                              javax.servlet.ServletContext ctxt)
                       throws javax.servlet.ServletException
        Specified by:
        onStartup in interface javax.servlet.ServletContainerInitializer
        Throws:
        javax.servlet.ServletException
      • getLocation

        public java.lang.String[] getLocation​(java.lang.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. 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
      • getTldMap

        java.util.Map<java.net.URI,​java.util.List<java.lang.String>> getTldMap()
      • getTldListenerMap

        java.util.Map<java.net.URI,​java.util.List<java.lang.String>> getTldListenerMap()
      • uriType

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

        private void scanTlds()
                       throws JasperException
        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
      • processWebDotXml

        private void processWebDotXml()
                               throws java.lang.Exception
        Throws:
        java.lang.Exception
      • scanJar

        private void scanJar​(java.net.JarURLConnection conn,
                             java.util.List<java.lang.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 a element, an implicit map entry is added to the taglib map.
        Parameters:
        conn - The JarURLConnection to the JAR file to scan
        tldNames - 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
      • addListener

        private void addListener​(TldScanner.TldInfo tldInfo,
                                 boolean isLocal)
      • mapTldLocation

        private void mapTldLocation​(java.lang.String resourcePath,
                                    TldScanner.TldInfo tldInfo,
                                    boolean isLocal)
      • scanTld

        private TldScanner.TldInfo scanTld​(java.lang.String resourcePath,
                                           java.lang.String entryName,
                                           java.io.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
      • scanJars

        private void scanJars()
                       throws java.lang.Exception
        Throws:
        java.lang.Exception
      • addManifestClassPath

        private boolean addManifestClassPath​(java.util.List<java.lang.String> scannedJars,
                                             java.util.List<java.lang.String> newJars,
                                             java.net.JarURLConnection jconn)