tldconfig.java

This temp directory is used by the JVM for temporary file storage. The JVM is configured to use thi

    /*
     * Returns the last modification date of the given sets of resources.
     *
     * @param resourcePaths
     * @param jarPaths
     *
     * @return Last modification date
     */
    private long getLastModified(Set resourcePaths, Map jarPaths)
            throws Exception {

        long lastModified = 0;

        Iterator paths = resourcePaths.iterator();
        while (paths.hasNext()) {
            String path = (String) paths.next();
            URL url = context.getServletContext().getResource(path);
            if (url == null) {
                log.debug( "Null url "+ path );
                break;
            }
            long lastM = url.openConnection().getLastModified();
            if (lastM > lastModified) lastModified = lastM;
            if (log.isDebugEnabled()) {
                log.debug( "Last modified " + path + " " + lastM);
            }
        }

        if (jarPaths != null) {
            paths = jarPaths.values().iterator();
            while (paths.hasNext()) {
                File jarFile = (File) paths.next();
                long lastM = jarFile.lastModified();
                if (lastM > lastModified) lastModified = lastM;
                if (log.isDebugEnabled()) {
                    log.debug("Last modified " + jarFile.getAbsolutePath()
                              + " " + lastM);
                }
            }
        }

        return lastModified;
    }

    private void processCache(File tldCache ) throws IOException {
        // read the cache and return;
        try {
            FileInputStream in=new FileInputStream(tldCache);
            ObjectInputStream ois=new ObjectInputStream( in );
            String list[]=(String [])ois.readObject();
            if( log.isDebugEnabled() )
                log.debug("Reusing tldCache " + tldCache + " " + list.length);
            for( int i=0; list!=null && i<list.length; i++ ) {
                context.addApplicationListener(list[i]);
            }
            ois.close();
        } catch( ClassNotFoundException ex ) {
            ex.printStackTrace();
        }
    }

    /**
     * Create (if necessary) and return a Digester configured to process a tag
     * library descriptor, looking for additional listener classes to be
     * registered.
     */
    private static Digester createTldDigester() {

        return DigesterFactory.newDigester(xmlValidation, 
                                           xmlNamespaceAware, 
                                           new TldRuleSet());

    }


    /**
     * Scan the JAR file at the specified resource path for TLDs in the
     * <code>META-INF</code> subdirectory, and scan each TLD for application
     * event listeners that need to be registered.
     *
     * @param resourcePath Resource path of the JAR file to scan
     *
     * @exception Exception if an exception occurs while scanning this JAR
     */
    private void tldScanJar(String resourcePath) throws Exception {

        if (log.isDebugEnabled()) {
            log.debug(" Scanning JAR at resource path '" + resourcePath + "'");
        }

        URL url = context.getServletContext().getResource(resourcePath);
        if (url == null) {
            throw new IllegalArgumentException
                                (sm.getString("contextConfig.tldResourcePath",
                                              resourcePath));
        }

        File file = new File(url.getFile());
        file = file.getCanonicalFile();
        tldScanJar(file);

    }

    /**
     * Scans all TLD entries in the given JAR for application listeners.
     *
     * @param file JAR file whose TLD entries are scanned for application
     * listeners
     */
    private void tldScanJar(File file) throws Exception {

        JarFile jarFile = null;
        String name = null;

        String jarPath = file.getAbsolutePath();

        try {
            jarFile = new JarFile(file);
            Enumeration entries = jarFile.entries();
            while (entries.hasMoreElements()) {
                JarEntry entry = (JarEntry) entries.nextElement();
                name = entry.getName();
                if (!name.startsWith("META-INF/")) {
                    continue;
                }
                if (!name.endsWith(".tld")) {
                    continue;
                }
                if (log.isTraceEnabled()) {
                    log.trace("  Processing TLD at '" + name + "'");
                }
                try {
                    tldScanStream(new InputSource(jarFile.getInputStream(entry)));
                } catch (Exception e) {
                    log.error(sm.getString("contextConfig.tldEntryException",
                                           name, jarPath, context.getPath()),
                              e);
                }
            }
        } catch (Exception e) {
            log.error(sm.getString("contextConfig.tldJarException",
                                   jarPath, context.getPath()),
                      e);
        } finally {
            if (jarFile != null) {
                try {
                    jarFile.close();
                } catch (Throwable t) {
                    // Ignore
                }
            }
        }
    }

    /**
     * Scan the TLD contents in the specified input stream, and register
     * any application event listeners found there.  <b>NOTE</b> - It is
     * the responsibility of the caller to close the InputStream after this
     * method returns.
     *
     * @param resourceStream InputStream containing a tag library descriptor
     *
     * @exception Exception if an exception occurs while scanning this TLD
     */
    private void tldScanStream(InputSource resourceStream)
        throws Exception {

        if (tldDigester == null){
            tldDigester = createTldDigester();
        }
        
        synchronized (tldDigester) {
            try {
                tldDigester.push(this);
                tldDigester.parse(resourceStream);
            } finally {
                tldDigester.push(null);
                tldDigester.clear();
            }
        }

    }

    /**
     * Scan the TLD contents at the specified resource path, and register
     * any application event listeners found there.
     *
     * @param resourcePath Resource path being scanned
     *
     * @exception Exception if an exception occurs while scanning this TLD
     */
    private void tldScanTld(String resourcePath) throws Exception {

        if (log.isDebugEnabled()) {
            log.debug(" Scanning TLD at resource path '" + resourcePath + "'");
        }

        InputSource inputSource = null;
        try {
            inputSource =
                new InputSource(
                    context.getServletContext().getResourceAsStream(resourcePath));
            if (inputSource == null) {
                throw new IllegalArgumentException
                    (sm.getString("contextConfig.tldResourcePath",
                                  resourcePath));
            }
            tldScanStream(inputSource);
        } catch (Exception e) {
             throw new ServletException
                 (sm.getString("contextConfig.tldFileException", resourcePath,
                               context.getPath()),
                  e);
        } 

    }

    /**
     * Accumulate and return a Set of resource paths to be analyzed for
     * tag library descriptors.  Each element of the returned set will be
     * the context-relative path to either a tag library descriptor file,
     * or to a JAR file that may contain tag library descriptors in its
     * <code>META-INF</code> subdirectory.
     *
     * @exception IOException if an input/output error occurs while
     *  accumulating the list of resource paths
     */
    private Set tldScanResourcePaths() throws IOException {
        if (log.isDebugEnabled()) {
            log.debug(" Accumulating TLD resource paths");
        }
        Set resourcePaths = new HashSet();

        // Accumulate resource paths explicitly listed in the web application
        // deployment descriptor
        if (log.isTraceEnabled()) {
            log.trace("  Scanning <taglib> elements in web.xml");
        }
        String taglibs[] = context.findTaglibs();
        for (int i = 0; i < taglibs.length; i++) {
            String resourcePath = context.findTaglib(taglibs[i]);
            // FIXME - Servlet 2.4 DTD implies that the location MUST be
            // a context-relative path starting with '/'?
            if (!resourcePath.startsWith("/")) {
                resourcePath = "/WEB-INF/" + resourcePath;
            }
            if (log.isTraceEnabled()) {
                log.trace("   Adding path '" + resourcePath +
                    "' for URI '" + taglibs[i] + "'");
            }
            resourcePaths.add(resourcePath);
        }

        DirContext resources = context.getResources();
        if (resources != null) {
            tldScanResourcePathsWebInf(resources, "/WEB-INF", resourcePaths);
        }

        // Return the completed set
        return (resourcePaths);

    }

    /*
     * Scans the web application's subdirectory identified by rootPath,
     * along with its subdirectories, for TLDs.
     *
     * Initially, rootPath equals /WEB-INF. The /WEB-INF/classes and
     * /WEB-INF/lib subdirectories are excluded from the search, as per the
     * JSP 2.0 spec.
     *
     * @param resources The web application's resources
     * @param rootPath The path whose subdirectories are to be searched for
     * TLDs
     * @param tldPaths The set of TLD resource paths to add to
     */
    private void tldScanResourcePathsWebInf(DirContext resources,
                                            String rootPath,
                                            Set tldPaths) 
            throws IOException {

        if (log.isTraceEnabled()) {
            log.trace("  Scanning TLDs in " + rootPath + " subdirectory");
        }

        try {
            NamingEnumeration items = resources.list(rootPath);
            while (items.hasMoreElements()) {
                NameClassPair item = (NameClassPair) items.nextElement();
                String resourcePath = rootPath + "/" + item.getName();
                if (!resourcePath.endsWith(".tld")
                        && (resourcePath.startsWith("/WEB-INF/classes")
                            || resourcePath.startsWith("/WEB-INF/lib"))) {
                    continue;
                }
                if (resourcePath.endsWith(".tld")) {
                    if (log.isTraceEnabled()) {
                        log.trace("   Adding path '" + resourcePath + "'");
                    }
                    tldPaths.add(resourcePath);
                } else {
                    tldScanResourcePathsWebInf(resources, resourcePath,
                                               tldPaths);
                }
            }
        } catch (NamingException e) {
            ; // Silent catch: it's valid that no /WEB-INF directory exists
        }
    }

    /**
     * Returns a map of the paths to all JAR files that are accessible to the
     * webapp and will be scanned for TLDs.
     *
     * The map always includes all the JARs under WEB-INF/lib, as well as
     * shared JARs in the classloader delegation chain of the webapp's
     * classloader.
     *
     * The latter constitutes a Tomcat-specific extension to the TLD search
     * order defined in the JSP spec. It allows tag libraries packaged as JAR
     * files to be shared by web applications by simply dropping them in a 
     * location that all web applications have access to (e.g.,
     * <CATALINA_HOME>/common/lib).
     *
     * The set of shared JARs to be scanned for TLDs is narrowed down by
     * the <tt>noTldJars</tt> class variable, which contains the names of JARs
     * that are known not to contain any TLDs.
     *
     * @return Map of JAR file paths
     */
    private Map getJarPaths() {

        HashMap jarPathMap = null;

        ClassLoader webappLoader = Thread.currentThread().getContextClassLoader();
        ClassLoader loader = webappLoader;
        while (loader != null) {
            if (loader instanceof URLClassLoader) {
                URL[] urls = ((URLClassLoader) loader).getURLs();
                for (int i=0; i<urls.length; i++) {
                    // Expect file URLs
                    // This is definitely not as clean as using JAR URLs either
                    // over file or the custom jndi handler, but a lot less
                    // buggy overall
                    File file = new File(urls[i].getFile());
                    try {
                        file = file.getCanonicalFile();
                    } catch (IOException e) {
                        // Ignore
                    }
                    if (!file.exists()) {
                        continue;
                    }
                    String path = file.getAbsolutePath();
                    if (!path.endsWith(".jar")) {
                        continue;
                    }
                    /*
                     * Scan all JARs from WEB-INF/lib, plus any shared JARs
                     * that are not known not to contain any TLDs
                     */
                    if (loader == webappLoader
                            || noTldJars == null
                            || !noTldJars.contains(file.getName())) {
                        if (jarPathMap == null) {
                            jarPathMap = new HashMap();
                            jarPathMap.put(path, file);
                        } else if (!jarPathMap.containsKey(path)) {
                            jarPathMap.put(path, file);
                        }
                    }
                }
            }
            loader = loader.getParent();
        }

        return jarPathMap;
    }
}