Class TldScanner

java.lang.Object
org.apache.jasper.runtime.TldScanner
All Implemented Interfaces:
javax.servlet.ServletContainerInitializer

public class TldScanner extends 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.
  • Field Details

    • log

      private static Logger log
    • ABS_URI

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

      public static final int ROOT_REL_URI
      See Also:
    • NOROOT_REL_URI

      public static final int NOROOT_REL_URI
      See Also:
    • WEB_XML

      private static final String WEB_XML
      See Also:
    • FILE_PROTOCOL

      private static final String FILE_PROTOCOL
      See Also:
    • JAR_FILE_SUFFIX

      private static final String JAR_FILE_SUFFIX
      See Also:
    • systemUris

      private static HashSet<String> systemUris
    • systemUrisJsf

      private static HashSet<String> systemUrisJsf
    • jarTldCache

      private static Map<String,TldScanner.TldInfo[]> jarTldCache
    • EAR_LIB_CLASSLOADER

      private static final String EAR_LIB_CLASSLOADER
      See Also:
    • IS_STANDALONE_ATTRIBUTE_NAME

      private static final String IS_STANDALONE_ATTRIBUTE_NAME
      See Also:
    • mappings

      private HashMap<String,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 Map<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 Details

    • 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 Details

    • onStartup

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

      Map<URI,List<String>> getTldMap()
    • getTldListenerMap

      Map<URI,List<String>> getTldListenerMap()
    • uriType

      public static int uriType(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 Exception
      Throws:
      Exception
    • 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 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(String resourcePath, TldScanner.TldInfo tldInfo, boolean isLocal)
    • processTldsInFileSystem

      private void processTldsInFileSystem(String startPath) throws JasperException
      Throws:
      JasperException
    • 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
    • scanJars

      private void scanJars() throws Exception
      Throws:
      Exception
    • addManifestClassPath

      private boolean addManifestClassPath(List<String> scannedJars, List<String> newJars, JarURLConnection jconn)