Package org.apache.jasper.compiler

Source Code of org.apache.jasper.compiler.TldLocationsCache

/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation.  All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in
*    the documentation and/or other materials provided with the
*    distribution.
*
* 3. The end-user documentation included with the redistribution, if
*    any, must include the following acknowlegement: 
*       "This product includes software developed by the
*        Apache Software Foundation (http://www.apache.org/)."
*    Alternately, this acknowlegement may appear in the software itself,
*    if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
*    Foundation" must not be used to endorse or promote products derived
*    from this software without prior written permission. For written
*    permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
*    nor may "Apache" appear in their names without prior written
*    permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation.  For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.jasper.compiler;

import java.io.InputStream;
import java.io.FileNotFoundException;
import java.io.File;
import java.io.IOException;
import java.io.DataInputStream;
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Set;
import java.util.jar.*;
import java.net.JarURLConnection;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.net.URL;

import javax.servlet.ServletContext;
import javax.servlet.jsp.tagext.TagLibraryInfo;
import javax.servlet.jsp.tagext.TagInfo;
import javax.servlet.jsp.tagext.Tag;

import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.jasper.xmlparser.ParserUtils;
import org.apache.jasper.xmlparser.TreeNode;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* 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";

    /**
     * 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.
     */
    private Hashtable mappings;

    private boolean initialized;
    private ServletContext ctxt;
    private boolean redeployMode;

    //*********************************************************************
    // Constructor and Initilizations
   
    public TldLocationsCache(ServletContext ctxt) {
        this(ctxt, true);
    }

    /** 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.
     */
    public TldLocationsCache(ServletContext ctxt, boolean redeployMode) {
        this.ctxt = ctxt;
        this.redeployMode = redeployMode;
        mappings = new Hashtable();
        initialized = false;
    }

    /**
     * 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;
        try {
            processWebDotXml();
            processJars();
      processTldsInFileSystem("/WEB-INF/");
      processTldsInGlobalJars();
            initialized = true;
        } catch (Exception ex) {
            throw new JasperException(Localizer.getMessage("jsp.error.internal.tldinit",
                 ex.getMessage()));
        }
    }

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

        // Acquire an input stream to the web application deployment descriptor
        InputStream is = ctxt.getResourceAsStream(WEB_XML);
        if (is == null) {
            if (log.isWarnEnabled()) {
    log.warn(Localizer.getMessage("jsp.error.internal.filenotfound",
                WEB_XML));
      }
            return;
        }

        // Parse the web application deployment descriptor
        TreeNode 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();
            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 });
        }
    }

    /**
     * Processes any JAR files contained in this web application's
     * WEB-INF/lib directory.
     */
    private void processJars() throws Exception {

        Set libSet = ctxt.getResourcePaths("/WEB-INF/lib");
        if (libSet != null) {
            Iterator it = libSet.iterator();
            while (it.hasNext()) {
                String resourcePath = (String) it.next();
                if (resourcePath.endsWith(JAR_FILE_SUFFIX)) {
        URL url = ctxt.getResource(resourcePath);
        if (url == null)
      return;
        URL jarURL = new URL("jar:" + url.toString() + "!/");
        processTldsInJar((JarURLConnection) jarURL.openConnection(),
             false);
    }
            }
        }
    }

    /**
     * Parses any TLD files located in the META-INF directory (or any
     * subdirectory of it) of the JAR file at the given resource path, and adds
     * an implicit map entry to the taglib map for any TLD that has a <uri>
     * element.
     *
     * @param conn The JarURLConnection to the JAR file containing the TLDs
     * @param ignore true if any exceptions raised when processing the given
     * JAR should be ignored, false otherwise
     */
    private void processTldsInJar(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 implicit map entry only if its uri is not already
        // present in the map
                    if (uri != null && mappings.get(uri) == null) {
                        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;
    }
    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) {
        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
        TreeNode tld = new ParserUtils().parseXMLDocument(resourcePath, in);
        TreeNode uri = tld.findChild("uri");
        if (uri != null) {
            String body = uri.getBody();
            if (body != null)
                return body;
        }

        return null;
    }

    /*
     * Processes any TLDs in all JAR files accessible to all parent
     * classloaders of the web application's classloader.
     *
     * This is a Tomcat-specific extension to the TLD search order defined in
     * the JSP spec, which will allow 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).
     */
    private void processTldsInGlobalJars() throws Exception {

  ClassLoader loader = Thread.currentThread().getContextClassLoader();
  while (loader != null) {
      if (loader instanceof URLClassLoader) {
    URL[] urls = ((URLClassLoader) loader).getURLs();
    for (int i=0; i<urls.length; i++) {
        URLConnection conn = urls[i].openConnection();
        if (conn instanceof JarURLConnection) {
      processTldsInJar((JarURLConnection) conn, true);
        } else {
      String urlStr = urls[i].toString();
      if (urlStr.startsWith(FILE_PROTOCOL)
                  && urlStr.endsWith(JAR_FILE_SUFFIX)) {
          URL jarURL = new URL("jar:" + urlStr + "!/");
          processTldsInJar((JarURLConnection)
               jarURL.openConnection(), true);
      }
        }
    }
      }
      loader = loader.getParent();
  }
    }
}
TOP

Related Classes of org.apache.jasper.compiler.TldLocationsCache

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.