/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jasper.compiler;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;
import java.util.StringTokenizer;
import javax.servlet.ServletContext;
import org.apache.jasper.JasperException;
import org.apache.jasper.util.ExceptionUtils;
import org.apache.jasper.xmlparser.ParserUtils;
import org.apache.jasper.xmlparser.TreeNode;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.JarScanner;
import org.apache.tomcat.JarScannerCallback;
import org.apache.tomcat.util.scan.Jar;
import org.apache.tomcat.util.scan.JarFactory;
/**
* 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 {
private static final Log log = LogFactory.getLog(TldLocationsCache.class);
private static final String KEY = TldLocationsCache.class.getName();
/**
* 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_INF = "/WEB-INF/";
private static final String WEB_INF_LIB = "/WEB-INF/lib/";
private static final String JAR_EXT = ".jar";
private static final String TLD_EXT = ".tld";
// Names of JARs that are known not to contain any TLDs
private static Set<String> noTldJars = null;
// Flag that indicates that an INFO level message has been provided that
// there are JARs that could be skipped
private static volatile boolean showTldScanWarning = true;
/**
* 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<String, TldLocation> mappings;
private volatile boolean initialized;
private ServletContext ctxt;
/** Constructor.
*
* @param ctxt the servlet context of the web application in which Jasper
* is running
*/
public TldLocationsCache(ServletContext ctxt) {
this.ctxt = ctxt;
mappings = new Hashtable<String, TldLocation>();
initialized = false;
}
/**
* Sets the list of JARs that are known not to contain any TLDs.
*
* @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) {
noTldJars = null;
} else {
if (noTldJars == null) {
noTldJars = new HashSet<String>();
} else {
noTldJars.clear();
}
StringTokenizer tokenizer = new StringTokenizer(jarNames, ",");
while (tokenizer.hasMoreElements()) {
noTldJars.add(tokenizer.nextToken());
}
}
}
/**
* Obtains the TLD location cache for the given {@link ServletContext} and
* creates one if one does not currently exist.
*/
public static synchronized TldLocationsCache getInstance(
ServletContext ctxt) {
if (ctxt == null) {
throw new IllegalArgumentException("ServletContext was null");
}
TldLocationsCache cache = (TldLocationsCache) ctxt.getAttribute(KEY);
if (cache == null) {
cache = new TldLocationsCache(ctxt);
ctxt.setAttribute(KEY, cache);
}
return cache;
}
/**
* 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 TldLocation getLocation(String uri) throws JasperException {
if (!initialized) {
init();
}
return 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;
}
}
/*
* Keep processing order in sync with o.a.c.startup.TldConfig
*
* This supports 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>/lib). It also supports some of the weird and
* wonderful arrangements present when Tomcat gets embedded.
*
*/
private synchronized void init() throws JasperException {
if (initialized) return;
try {
tldScanWebXml();
tldScanResourcePaths(WEB_INF);
JarScanner jarScanner = JarScannerFactory.getJarScanner(ctxt);
if (jarScanner != null) {
jarScanner.scan(ctxt,
Thread.currentThread().getContextClassLoader(),
new TldJarScannerCallback(), noTldJars);
}
initialized = true;
} catch (Exception ex) {
throw new JasperException(Localizer.getMessage(
"jsp.error.internal.tldinit", ex.getMessage()), ex);
}
}
private class TldJarScannerCallback implements JarScannerCallback {
@Override
public void scan(JarURLConnection urlConn) throws IOException {
tldScanJar(urlConn);
}
@Override
public void scan(File file) throws IOException {
File metaInf = new File(file, "META-INF");
if (metaInf.isDirectory()) {
tldScanDir(metaInf);
}
}
}
/*
* Populates taglib map described in web.xml.
*
* This is not kept in sync with o.a.c.startup.TldConfig as the Jasper only
* needs the URI to TLD mappings from scan web.xml whereas TldConfig needs
* to scan the actual TLD files.
*/
private void tldScanWebXml() throws Exception {
WebXml webXml = null;
try {
webXml = new WebXml(ctxt);
if (webXml.getInputSource() == null) {
return;
}
// Parse the web application deployment descriptor
TreeNode webtld = null;
webtld = new ParserUtils().parseXMLDocument(webXml.getSystemId(),
webXml.getInputSource());
// 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<TreeNode> taglibs = webtld.findChildren("taglib");
while (taglibs.hasNext()) {
// Parse the next <taglib> element
TreeNode taglib = 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;
TldLocation location;
if (tagLoc.endsWith(JAR_EXT)) {
location = new TldLocation("META-INF/taglib.tld", ctxt.getResource(tagLoc).toString());
} else {
location = new TldLocation(tagLoc);
}
mappings.put(tagUri, location);
}
} finally {
if (webXml != null) {
webXml.close();
}
}
}
/*
* Scans the web application's sub-directory identified by startPath,
* along with its sub-directories, for TLDs and adds an implicit map entry
* to the taglib map for any TLD that has a <uri> element.
*
* Initially, rootPath equals /WEB-INF/. The /WEB-INF/classes and
* /WEB-INF/lib sub-directories are excluded from the search, as per the
* JSP 2.0 spec.
*
* Keep code in sync with o.a.c.startup.TldConfig
*/
private void tldScanResourcePaths(String startPath)
throws Exception {
Set<String> dirList = ctxt.getResourcePaths(startPath);
if (dirList != null) {
Iterator<String> it = dirList.iterator();
while (it.hasNext()) {
String path = it.next();
if (!path.endsWith(TLD_EXT)
&& (path.startsWith(WEB_INF_LIB)
|| path.startsWith("/WEB-INF/classes/"))) {
continue;
}
if (path.endsWith(TLD_EXT)) {
if (path.startsWith("/WEB-INF/tags/") &&
!path.endsWith("implicit.tld")) {
continue;
}
InputStream stream = ctxt.getResourceAsStream(path);
try {
tldScanStream(path, null, stream);
} finally {
if (stream != null) {
try {
stream.close();
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
}
}
}
} else {
tldScanResourcePaths(path);
}
}
}
}
/*
* Scans the directory identified by startPath, along with its
* sub-directories, for TLDs.
*
* Keep in sync with o.a.c.startup.TldConfig
*/
private void tldScanDir(File start) throws IOException {
File[] fileList = start.listFiles();
if (fileList != null) {
for (int i = 0; i < fileList.length; i++) {
// Scan recursively
if (fileList[i].isDirectory()) {
tldScanDir(fileList[i]);
} else if (fileList[i].getAbsolutePath().endsWith(TLD_EXT)) {
InputStream stream = null;
try {
stream = new FileInputStream(fileList[i]);
tldScanStream(
fileList[i].toURI().toString(), null, stream);
} finally {
if (stream != null) {
try {
stream.close();
} catch (Throwable t) {
ExceptionUtils.handleThrowable(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 jarConn The JarURLConnection to the JAR file to scan
*
* Keep in sync with o.a.c.startup.TldConfig
*/
private void tldScanJar(JarURLConnection jarConn) throws IOException {
Jar jar = null;
InputStream is;
boolean foundTld = false;
URL resourceURL = jarConn.getJarFileURL();
String resourcePath = resourceURL.toString();
try {
jar = JarFactory.newInstance(jarConn.getURL());
jar.nextEntry();
String entryName = jar.getEntryName();
while (entryName != null) {
if (entryName.startsWith("META-INF/") &&
entryName.endsWith(".tld")) {
is = null;
try {
is = jar.getEntryInputStream();
foundTld = true;
tldScanStream(resourcePath, entryName, is);
} finally {
if (is != null) {
try {
is.close();
} catch (IOException ioe) {
// Ignore
}
}
}
}
jar.nextEntry();
entryName = jar.getEntryName();
}
} finally {
if (jar != null) {
jar.close();
}
}
if (!foundTld) {
if (log.isDebugEnabled()) {
log.debug(Localizer.getMessage("jsp.tldCache.noTldInJar",
resourcePath));
} else if (showTldScanWarning) {
// Not entirely thread-safe but a few duplicate log messages are
// not a huge issue
showTldScanWarning = false;
log.info(Localizer.getMessage("jsp.tldCache.noTldSummary"));
}
}
}
/*
* Scan the TLD contents in the specified input stream and add any new URIs
* to the map.
*
* @param resourcePath Path of the resource
* @param entryName If the resource is a JAR file, the name of the entry
* in the JAR file
* @param stream The input stream for the resource
* @throws IOException
*/
private void tldScanStream(String resourcePath, String entryName,
InputStream stream) throws IOException {
try {
// Parse the tag library descriptor at the specified resource path
String uri = null;
TreeNode tld =
new ParserUtils().parseXMLDocument(resourcePath, stream);
TreeNode uriNode = tld.findChild("uri");
if (uriNode != null) {
String body = uriNode.getBody();
if (body != null)
uri = body;
}
// Add implicit map entry only if its uri is not already
// present in the map
if (uri != null && mappings.get(uri) == null) {
TldLocation location;
if (entryName == null) {
location = new TldLocation(resourcePath);
} else {
location = new TldLocation(entryName, resourcePath);
}
mappings.put(uri, location);
}
} catch (JasperException e) {
// Hack - makes exception handling simpler
throw (IOException)new IOException("JasperException:").initCause(e);
}
}
}