xmlcatalog.java

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     * @param publicId the public id to resolve.
     * @param systemId the system id to resolve.
     * @throws SAXException if there is a parsing problem.
     * @throws IOException if there is an IO problem.
     * @return the resolved entity.
     * @see org.xml.sax.EntityResolver#resolveEntity
     */
    public InputSource resolveEntity(String publicId, String systemId)
        throws SAXException, IOException {

        if (isReference()) {
            return getRef().resolveEntity(publicId, systemId);
        }

        dieOnCircularReference();

        log("resolveEntity: '" + publicId + "': '" + systemId + "'",
            Project.MSG_DEBUG);

        InputSource inputSource =
            getCatalogResolver().resolveEntity(publicId, systemId);

        if (inputSource == null) {
            log("No matching catalog entry found, parser will use: '"
                + systemId + "'", Project.MSG_DEBUG);
        }

        return inputSource;
    }

    /**
     * Implements the URIResolver.resolve() interface method.
     * @param href an href attribute.
     * @param base the base URI.
     * @return a Source object, or null if href cannot be resolved.
     * @throws TransformerException if an error occurs.
     * @see javax.xml.transform.URIResolver#resolve
     */
    public Source resolve(String href, String base)
        throws TransformerException {

        if (isReference()) {
            return getRef().resolve(href, base);
        }

        dieOnCircularReference();

        SAXSource source = null;

        String uri = removeFragment(href);

        log("resolve: '" + uri + "' with base: '" + base + "'", Project.MSG_DEBUG);

        source = (SAXSource) getCatalogResolver().resolve(uri, base);

        if (source == null) {
            log("No matching catalog entry found, parser will use: '"
                + href + "'", Project.MSG_DEBUG);
            //
            // Cannot return a null source, because we have to call
            // setEntityResolver (see setEntityResolver javadoc comment)
            //
            source = new SAXSource();
            URL baseURL = null;
            try {
                if (base == null) {
                    baseURL = FILE_UTILS.getFileURL(getProject().getBaseDir());
                } else {
                    baseURL = new URL(base);
                }
                URL url = (uri.length() == 0 ? baseURL : new URL(baseURL, uri));
                source.setInputSource(new InputSource(url.toString()));
            } catch (MalformedURLException ex) {
                // At this point we are probably in failure mode, but
                // try to use the bare URI as a last gasp
                source.setInputSource(new InputSource(uri));
            }
        }

        setEntityResolver(source);
        return source;
    }

    /**
     * @since Ant 1.6
     */
    private XMLCatalog getRef() {
        if (!isReference()) {
            return this;
        }
        return (XMLCatalog) getCheckedRef(XMLCatalog.class, "xmlcatalog");
    }

    /**
     * The instance of the CatalogResolver strategy to use.
     */
    private CatalogResolver catalogResolver = null;

    /**
     * Factory method for creating the appropriate CatalogResolver
     * strategy implementation.
     * <p> Until we query the classpath, we don't know whether the Apache
     * resolver (Norm Walsh's library from xml-commons) is available or not.
     * This method determines whether the library is available and creates the
     * appropriate implementation of CatalogResolver based on the answer.</p>
     * <p>This is an application of the Gang of Four Strategy Pattern
     * combined with Template Method.</p>
     */
    private CatalogResolver getCatalogResolver() {

        if (catalogResolver == null) {

            AntClassLoader loader = null;

            loader = getProject().createClassLoader(Path.systemClasspath);

            try {
                Class clazz = Class.forName(APACHE_RESOLVER, true, loader);

                // The Apache resolver is present - Need to check if it can
                // be seen by the catalog resolver class. Start by getting
                // the actual loader
                ClassLoader apacheResolverLoader = clazz.getClassLoader();

                // load the base class through this loader.
                Class baseResolverClass
                    = Class.forName(CATALOG_RESOLVER, true, apacheResolverLoader);

                // and find its actual loader
                ClassLoader baseResolverLoader
                    = baseResolverClass.getClassLoader();

                // We have the loader which is being used to load the
                // CatalogResolver. Can it see the ApacheResolver? The
                // base resolver will only be able to create the ApacheResolver
                // if it can see it - doesn't use the context loader.
                clazz = Class.forName(APACHE_RESOLVER, true, baseResolverLoader);

                Object obj  = clazz.newInstance();
                //
                // Success!  The xml-commons resolver library is
                // available, so use it.
                //
                catalogResolver = new ExternalResolver(clazz, obj);
            } catch (Throwable ex) {
                //
                // The xml-commons resolver library is not
                // available, so we can't use it.
                //
                catalogResolver = new InternalResolver();
                if (getCatalogPath() != null
                    && getCatalogPath().list().length != 0) {
                        log("Warning: XML resolver not found; external catalogs"
                            + " will be ignored", Project.MSG_WARN);
                    }
                log("Failed to load Apache resolver: " + ex, Project.MSG_DEBUG);
            }
        }
        return catalogResolver;
    }

    /**
     * <p>This is called from the URIResolver to set an EntityResolver
     * on the SAX parser to be used for new XML documents that are
     * encountered as a result of the document() function, xsl:import,
     * or xsl:include.  This is done because the XSLT processor calls
     * out to the SAXParserFactory itself to create a new SAXParser to
     * parse the new document.  The new parser does not automatically
     * inherit the EntityResolver of the original (although arguably
     * it should).  See below:</p>
     *
     * <tt>"If an application wants to set the ErrorHandler or
     * EntityResolver for an XMLReader used during a transformation,
     * it should use a URIResolver to return the SAXSource which
     * provides (with getXMLReader) a reference to the XMLReader"</tt>
     *
     * <p>...quoted from page 118 of the Java API for XML
     * Processing 1.1 specification</p>
     *
     */
    private void setEntityResolver(SAXSource source) throws TransformerException {

        XMLReader reader = source.getXMLReader();
        if (reader == null) {
            SAXParserFactory spFactory = SAXParserFactory.newInstance();
            spFactory.setNamespaceAware(true);
            try {
                reader = spFactory.newSAXParser().getXMLReader();
            } catch (ParserConfigurationException ex) {
                throw new TransformerException(ex);
            } catch (SAXException ex) {
                throw new TransformerException(ex);
            }
        }
        reader.setEntityResolver(this);
        source.setXMLReader(reader);
    }

    /**
     * Find a ResourceLocation instance for the given publicId.
     *
     * @param publicId the publicId of the Resource for which local information
     *        is required.
     * @return a ResourceLocation instance with information on the local location
     *         of the Resource or null if no such information is available.
     */
    private ResourceLocation findMatchingEntry(String publicId) {
        Enumeration e = getElements().elements();
        ResourceLocation element = null;
        while (e.hasMoreElements()) {
            Object o = e.nextElement();
            if (o instanceof ResourceLocation) {
                element = (ResourceLocation) o;
                if (element.getPublicId().equals(publicId)) {
                    return element;
                }
            }
        }
        return null;
    }

    /**
     * Utility method to remove trailing fragment from a URI.
     * For example,
     * <code>http://java.sun.com/index.html#chapter1</code>
     * would return <code>http://java.sun.com/index.html</code>.
     *
     * @param uri The URI to process.  It may or may not contain a
     *            fragment.
     * @return The URI sans fragment.
     */
    private String removeFragment(String uri) {
        String result = uri;
        int hashPos = uri.indexOf("#");
        if (hashPos >= 0) {
            result = uri.substring(0, hashPos);
        }
        return result;
    }

    /**
     * Utility method to lookup a ResourceLocation in the filesystem.
     *
     * @return An InputSource for reading the file, or <code>null</code>
     *     if the file does not exist or is not readable.
     */
    private InputSource filesystemLookup(ResourceLocation matchingEntry) {

        String uri = matchingEntry.getLocation();
        // the following line seems to be necessary on Windows under JDK 1.2
        uri = uri.replace(File.separatorChar, '/');
        URL baseURL = null;

        //
        // The ResourceLocation may specify a relative path for its
        // location attribute.  This is resolved using the appropriate
        // base.
        //
        if (matchingEntry.getBase() != null) {
            baseURL = matchingEntry.getBase();
        } else {
            try {
                baseURL = FILE_UTILS.getFileURL(getProject().getBaseDir());
            } catch (MalformedURLException ex) {
                throw new BuildException("Project basedir cannot be converted to a URL");
            }
        }

        InputSource source = null;
        URL url = null;
        try {
            url = new URL(baseURL, uri);
        } catch (MalformedURLException ex) {
            // this processing is useful under Windows when the location of the DTD
            // has been given as an absolute path
            // see Bugzilla Report 23913
            File testFile = new File(uri);
            if (testFile.exists() && testFile.canRead()) {
                log("uri : '"
                    + uri + "' matches a readable file", Project.MSG_DEBUG);
                try {
                    url = FILE_UTILS.getFileURL(testFile);
                } catch (MalformedURLException ex1) {
                    throw new BuildException(
                        "could not find an URL for :" + testFile.getAbsolutePath());
                }
            } else {
                log("uri : '"
                    + uri + "' does not match a readable file", Project.MSG_DEBUG);

            }
        }

        if (url != null && url.getProtocol().equals("file")) {
            String fileName = FILE_UTILS.fromURI(url.toString());
            if (fileName != null) {
                log("fileName " + fileName, Project.MSG_DEBUG);
                File resFile = new File(fileName);
                if (resFile.exists() && resFile.canRead()) {
                    try {
                        source = new InputSource(new FileInputStream(resFile));
                        String sysid = JAXPUtils.getSystemId(resFile);
                        source.setSystemId(sysid);
                        log("catalog entry matched a readable file: '"
                            + sysid + "'", Project.MSG_DEBUG);
                    } catch (IOException ex) {
                        // ignore
                    }
                }
            }
        }
        return source;
    }

    /**
     * Utility method to lookup a ResourceLocation in the classpath.
     *
     * @return An InputSource for reading the resource, or <code>null</code>
     *    if the resource does not exist in the classpath or is not readable.
     */
    private InputSource classpathLookup(ResourceLocation matchingEntry) {

        InputSource source = null;

        AntClassLoader loader = null;
        Path cp = classpath;
        if (cp != null) {
            cp = classpath.concatSystemClasspath("ignore");
        } else {
            cp = (new Path(getProject())).concatSystemClasspath("last");
        }
        loader = getProject().createClassLoader(cp);

        //
        // for classpath lookup we ignore the base directory
        //
        InputStream is
            = loader.getResourceAsStream(matchingEntry.getLocation());

        if (is != null) {
            source = new InputSource(is);
            URL entryURL = loader.getResource(matchingEntry.getLocation());
            String sysid = entryURL.toExternalForm();
            source.setSystemId(sysid);
            log("catalog entry matched a resource in the classpath: '"
                + sysid + "'", Project.MSG_DEBUG);
        }

        return source;
    }

    /**
     * Utility method to lookup a ResourceLocation in URL-space.
     *
     * @return An InputSource for reading the resource, or <code>null</code>
     *    if the resource does not identify a valid URL or is not readable.
     */
    private InputSource urlLookup(ResourceLocation matchingEntry) {

        String uri = matchingEntry.getLocation();
        URL baseURL = null;

        //
        // The ResourceLocation may specify a relative url for its
        // location attribute.  This is resolved using the appropriate
        // base.
        //
        if (matchingEntry.getBase() != null) {
            baseURL = matchingEntry.getBase();
        } else {