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TldLocationsCache.javaAPI DocGlassfish v2 API24315Fri May 04 22:32:52 BST 2007org.apache.jasper.compiler

TldLocationsCache.java


/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * Portions Copyright Apache Software Foundation.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
package org.apache.jasper.compiler;

import java.io.InputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.util.Enumeration;
/* GlassFish 747
import java.util.Hashtable;
*/
// START GlassFish 747
import java.util.HashMap;
// END GlassFish 747
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import javax.servlet.ServletContext;

import com.sun.org.apache.commons.logging.Log;
import com.sun.org.apache.commons.logging.LogFactory;
import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
// START SJSAS 6384538
import org.apache.jasper.Options;
// END SJSAS 6384538
import org.apache.jasper.xmlparser.ParserUtils;
import org.apache.jasper.xmlparser.TreeNode;

/**
 * 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 <taglib> elements in web.xml:
 *      the uri and location of the tag-library are specified in
 *      the <taglib> 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 <uri>
 *      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.
 *
 * @author Pierre Delisle
 * @author Jan Luehe
 */

public class TldLocationsCache {

    // Logger
    private static Log log = LogFactory.getLog(TldLocationsCache.class);

    /**
     * The types of URI one may specify for a tag library
     */
    public static final int ABS_URI = 0;
    public static final int ROOT_REL_URI = 1;
    public static final int NOROOT_REL_URI = 2;

    private static final String WEB_XML = "/WEB-INF/web.xml";
    private static final String FILE_PROTOCOL = "file:";
    private static final String JAR_FILE_SUFFIX = ".jar";

    // Names of JARs that are known not to contain any TLDs
    private static HashSet<String> noTldJars;

    // Names of system Uri's that are ignored if referred in WEB-INF/web.xml
    private static HashSet<String> systemUris = new HashSet<String>();
    private static HashSet<String> systemUrisJsf = new HashSet<String>();

    /**
     * The mapping of the 'global' tag library URI to the location (resource
     * path) of the TLD associated with that tag library. The location is
     * returned as a String array:
     *    [0] The location
     *    [1] If the location is a jar file, this is the location of the tld.
     */
    /* GlassFish 747
    private Hashtable mappings;
     */
    // START GlassFish 747
    private HashMap mappings;
    // END GlassFish 747

    private boolean initialized;
    private ServletContext ctxt;
    private boolean redeployMode;
    // START SJSAS 6384538
    private Options options;
    // END SJSAS 6384538

    // START GlassFish 747
    private boolean localTldsProcessed = false;
    // END GlassFish 747

    private boolean useMyFaces = false;


    //*********************************************************************
    // Constructor and Initilizations
    
    /*
     * Initializes the set of JARs that are known not to contain any TLDs
     */
    static {
        systemUrisJsf.add("http://java.sun.com/jsf/core");
        systemUrisJsf.add("http://java.sun.com/jsf/html");
        systemUris.add("http://java.sun.com/jsp/jstl/core");
    }

    /* SJSAS 6384538
    public TldLocationsCache(ServletContext ctxt) {
    */
    // START SJSAS 6384538
    public TldLocationsCache(ServletContext ctxt, Options options) {
    // END SJSAS 6384538
        /* SJSAS 6384538
        this(ctxt, true);
        */
        // START SJSAS 6384538
        this(ctxt, options, true);
        // END SJSAS 6384538
    }

    /** Constructor. 
     *
     * @param ctxt the servlet context of the web application in which Jasper 
     * is running
     * @param redeployMode if true, then the compiler will allow redeploying 
     * a tag library from the same jar, at the expense of slowing down the
     * server a bit. Note that this may only work on JDK 1.3.1_01a and later,
     * because of JDK bug 4211817 fixed in this release.
     * If redeployMode is false, a faster but less capable mode will be used.
     */
    /* SJSAS 6384538
    public TldLocationsCache(ServletContext ctxt, boolean redeployMode) {
    */
    // START SJSAS 6384538
    public TldLocationsCache(ServletContext ctxt, Options options,
                             boolean redeployMode) {
    // END SJSAS 6384538
        this.ctxt = ctxt;
        // START SJSAS 6384538
        this.options = options;
        // END SJSAS 6384538
        this.redeployMode = redeployMode;
        /* GlassFish 747
        mappings = new Hashtable();
        */

        Boolean b = (Boolean) ctxt.getAttribute("com.sun.faces.useMyFaces");
        if (b != null) {
            useMyFaces = b.booleanValue();
        }
        initialized = false;
    }

    /**
     * Sets the list of JAR files that are known not to contain any TLDs.
     *
     * Only shared JAR files (that is, those loaded by a delegation parent
     * of the webapp's classloader) will be checked against this list.
     *
     * @param jarNames List of comma-separated names of JAR files that are 
     * known not to contain any TLDs 
     */
    public static void setNoTldJars(String jarNames) {
        if (jarNames != null) {
            if (noTldJars == null) {
                noTldJars = new HashSet<String>();
            } else {
                noTldJars.clear();
            }
            StringTokenizer tokenizer = new StringTokenizer(jarNames, ",");
            while (tokenizer.hasMoreElements()) {
                noTldJars.add(tokenizer.nextToken());
            }
        }
    }

    /**
     * Sets the list of JAR files that are known not to contain any TLDs.
     *
     * Only shared JAR files (that is, those loaded by a delegation parent
     * of the webapp's classloader) will be checked against this list.
     *
     * @param set HashSet containing the names of JAR files known not to
     * contain any TLDs
     */
    public static void setNoTldJars(HashSet<String> set) {
        noTldJars = set;
    }

    /**
     * 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).
     * 
     * @param uri The taglib uri
     *
     * @return 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.
     */
    public String[] getLocation(String uri) throws JasperException {
        if (!initialized) {
            init();
        }
        return (String[]) mappings.get(uri);
    }

    /** 
     * Returns the type of a URI:
     *     ABS_URI
     *     ROOT_REL_URI
     *     NOROOT_REL_URI
     */
    public static int uriType(String uri) {
        if (uri.indexOf(':') != -1) {
            return ABS_URI;
        } else if (uri.startsWith("/")) {
            return ROOT_REL_URI;
        } else {
            return NOROOT_REL_URI;
        }
    }

    private void init() throws JasperException {
        if (initialized) return;

        // START GlassFish 747
        HashMap tldUriToLocationMap = (HashMap) ctxt.getAttribute(
            Constants.JSP_TLD_URI_TO_LOCATION_MAP);
        if (tldUriToLocationMap != null) {
            localTldsProcessed = true;
            mappings = tldUriToLocationMap;
        } else {
            mappings = new HashMap();
        }
        // END GlassFish 747
        try {
            /* GlassFish 747
            processWebDotXml();
            */
            // START Glassfish 747
            if (!localTldsProcessed) {
                processWebDotXml();
            }
            // END Glassfish 747
            scanJars();
            /* GlassFish 747
            processTldsInFileSystem("/WEB-INF/");
            */
            // START GlassFish 747
            if (!localTldsProcessed) {
                processTldsInFileSystem("/WEB-INF/");
            }
            // END Glassfish 747
            initialized = true;
        } catch (Exception ex) {
            throw new JasperException(
                Localizer.getMessage("jsp.error.internal.tldinit"),
                ex);
        }
    }

    /*
     * Populates taglib map described in web.xml.
     */    
    private void processWebDotXml() throws Exception {

        InputStream is = null;

        try {
            // Acquire input stream to web application deployment descriptor
            String altDDName = (String)ctxt.getAttribute(
                                                    Constants.ALT_DD_ATTR);
            if (altDDName != null) {
                try {
                    is = new FileInputStream(altDDName);
                } catch (FileNotFoundException e) {
                    if (log.isWarnEnabled()) {
                        log.warn(Localizer.getMessage(
                                            "jsp.error.internal.filenotfound",
                                            altDDName));
                    }
                }
            } else {
                is = ctxt.getResourceAsStream(WEB_XML);
                /* SJSAS 6396582
                if (is == null && log.isWarnEnabled()) {
                    log.warn(Localizer.getMessage(
                                            "jsp.error.internal.filenotfound",
                                            WEB_XML));
                }
                */
            }

            if (is == null) {
                return;
            }

            // Parse the web application deployment descriptor
            TreeNode webtld = null;
            // altDDName is the absolute path of the DD
            if (altDDName != null) {
                webtld = new ParserUtils().parseXMLDocument(altDDName, is);
            } else {
                webtld = new ParserUtils().parseXMLDocument(WEB_XML, is);
            }

            // Allow taglib to be an element of the root or jsp-config (JSP2.0)
            TreeNode jspConfig = webtld.findChild("jsp-config");
            if (jspConfig != null) {
                webtld = jspConfig;
            }
            Iterator taglibs = webtld.findChildren("taglib");
            while (taglibs.hasNext()) {

                // Parse the next <taglib> element
                TreeNode taglib = (TreeNode) taglibs.next();
                String tagUri = null;
                String tagLoc = null;
                TreeNode child = taglib.findChild("taglib-uri");
                if (child != null)
                    tagUri = child.getBody();
                // Ignore system tlds in web.xml, for backward compatibility
                if (systemUris.contains(tagUri)
                        || (!useMyFaces && systemUrisJsf.contains(tagUri))) {
                    continue;
                }
                child = taglib.findChild("taglib-location");
                if (child != null)
                    tagLoc = child.getBody();

                // Save this location if appropriate
                if (tagLoc == null)
                    continue;
                if (uriType(tagLoc) == NOROOT_REL_URI)
                    tagLoc = "/WEB-INF/" + tagLoc;
                String tagLoc2 = null;
                if (tagLoc.endsWith(JAR_FILE_SUFFIX)) {
                    tagLoc = ctxt.getResource(tagLoc).toString();
                    tagLoc2 = "META-INF/taglib.tld";
                }
                mappings.put(tagUri, new String[] { tagLoc, tagLoc2 });
            }
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (Throwable t) {}
            }
        }
    }

    /**
     * Scans the given JarURLConnection for TLD files located in META-INF
     * (or a subdirectory of it), adding an implicit map entry to the taglib
     * map for any TLD that has a <uri> element.
     *
     * @param conn The JarURLConnection to the JAR file to scan
     * @param ignore true if any exceptions raised when processing the given
     * JAR should be ignored, false otherwise
     */
    private void scanJar(JarURLConnection conn, boolean ignore)
            throws JasperException {

        JarFile jarFile = null;
        String resourcePath = conn.getJarFileURL().toString();
        try {
            if (redeployMode) {
                conn.setUseCaches(false);
            }
            jarFile = conn.getJarFile();
            Enumeration entries = jarFile.entries();
            while (entries.hasMoreElements()) {
                JarEntry entry = (JarEntry) entries.nextElement();
                String name = entry.getName();
                if (!name.startsWith("META-INF/")) continue;
                if (!name.endsWith(".tld")) continue;
                InputStream stream = jarFile.getInputStream(entry);
                try {
                    String uri = getUriFromTld(resourcePath, stream);
                    // Add map entry.
                    // Override existing entries as we move higher
                    // up in the classloader delegation chain.
                    if (uri != null
                            && (mappings.get(uri) == null
                                || systemUris.contains(uri)
                                || (systemUrisJsf.contains(uri)
                                    && !useMyFaces))) {
                        mappings.put(uri, new String[]{ resourcePath, name });
                    }
                } finally {
                    if (stream != null) {
                        try {
                            stream.close();
                        } catch (Throwable t) {
                            // do nothing
                        }
                    }
                }
            }
        } catch (Exception ex) {
            if (!redeployMode) {
                // if not in redeploy mode, close the jar in case of an error
                if (jarFile != null) {
                    try {
                        jarFile.close();
                    } catch (Throwable t) {
                        // ignore
                    }
                }
            }
            if (!ignore) {
                throw new JasperException(ex);
            }
        } finally {
            if (redeployMode) {
                // if in redeploy mode, always close the jar
                if (jarFile != null) {
                    try {
                        jarFile.close();
                    } catch (Throwable t) {
                        // ignore
                    }
                }
            }
        }
    }

    /*
     * Searches the filesystem under /WEB-INF for any TLD files, and adds
     * an implicit map entry to the taglib map for any TLD that has a <uri>
     * element.
     */
    private void processTldsInFileSystem(String startPath)
            throws Exception {

        Set dirList = ctxt.getResourcePaths(startPath);
        if (dirList != null) {
            Iterator it = dirList.iterator();
            while (it.hasNext()) {
                String path = (String) it.next();
                if (path.endsWith("/")) {
                    processTldsInFileSystem(path);
                }
                if (!path.endsWith(".tld")) {
                    continue;
                }
                if (path.startsWith("/WEB-INF/tags/")
                        && !path.endsWith("implicit.tld")) {
                    throw new JasperException(
                        Localizer.getMessage(
                                "jsp.error.tldinit.tldInWebInfTags",
                                path));
                }
                InputStream stream = ctxt.getResourceAsStream(path);
                String uri = null;
                try {
                    uri = getUriFromTld(path, stream);
                } finally {
                    if (stream != null) {
                        try {
                            stream.close();
                        } catch (Throwable t) {
                            // do nothing
                        }
                    }
                }
                // Add implicit map entry only if its uri is not already
                // present in the map
                if (uri != null
                         && mappings.get(uri) == null
                         && !systemUris.contains(uri)
                         && (!systemUrisJsf.contains(uri)
                             || useMyFaces)) {
                    mappings.put(uri, new String[] { path, null });
                }
            }
        }
    }

    /*
     * Returns the value of the uri element of the given TLD, or null if the
     * given TLD does not contain any such element.
     */
    private String getUriFromTld(String resourcePath, InputStream in) 
        throws JasperException
    {
        // Parse the tag library descriptor at the specified resource path
        /* SJSAS 6384538
        TreeNode tld = new ParserUtils().parseXMLDocument(resourcePath, in);
        */
        // START SJSAS 6384538
        TreeNode tld = new ParserUtils().parseXMLDocument(
            resourcePath, in, options.isValidationEnabled());
        // END SJSAS 6384538
        TreeNode uri = tld.findChild("uri");
        if (uri != null) {
            String body = uri.getBody();
            if (body != null)
                return body;
        }

        return null;
    }

    /*
     * Scans all JARs accessible to the webapp's classloader and its
     * parent classloaders for TLDs.
     * 
     * The list of JARs always includes the JARs under WEB-INF/lib, as well as
     * all shared JARs in the classloader delegation chain of the webapp's
     * classloader.
     *
     * Considering JARs in the classloader delegation chain 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.
     */
    private void scanJars() throws Exception {

        ClassLoader webappLoader
            = Thread.currentThread().getContextClassLoader();
        ClassLoader loader = webappLoader;

        // START Glassfish 747
        if (localTldsProcessed) {
            if (loader != null) {
                loader = loader.getParent();
            }
        }
        // END GlassFish 747

        while (loader != null) {
            if (loader instanceof URLClassLoader) {
                boolean isLocal = (loader == webappLoader);
                URL[] urls = ((URLClassLoader) loader).getURLs();
                for (int i=0; i<urls.length; i++) {
                    URLConnection conn = urls[i].openConnection();
                    if (conn instanceof JarURLConnection) {
                        if (needScanJar(
                                ((JarURLConnection) conn).getJarFile().getName(),
                                isLocal)) {
                            scanJar((JarURLConnection) conn, true);
                        }
                    } else {
                        String urlStr = urls[i].toString();
                        if (urlStr.startsWith(FILE_PROTOCOL)
                                && urlStr.endsWith(JAR_FILE_SUFFIX)
                                && needScanJar(urlStr, isLocal)) {
                            URL jarURL = new URL("jar:" + urlStr + "!/");
                            scanJar((JarURLConnection) jarURL.openConnection(),
                                    true);
                        }
                    }
                }
            }

            loader = loader.getParent();
        }
    }

    /*
     * Determines if the JAR file with the given <tt>jarPath</tt> needs to be
     * scanned for TLDs.
     *
     * @param jarPath The JAR file path
     * @param isLocal true if the JAR file with the given jarPath is local to 
     * the webapp (and therefore needs to be scanned unconditionally), false
     * otherwise
     *
     * @return true if the JAR file identified by <tt>jarPath</tt> needs to be
     * scanned for TLDs, false otherwise
     */
    private boolean needScanJar(String jarPath, boolean isLocal) {

        if (isLocal) {
            return true;
        }

        String jarName = jarPath;
        int slash = jarPath.lastIndexOf('/');
        if (slash >= 0) {
            jarName = jarPath.substring(slash + 1);
        }
        return ((noTldJars == null) || !noTldJars.contains(jarName));
    }
}