org.apache.jasper.compiler.TldCache Maven / Gradle / Ivy
/*
* 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.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import javax.servlet.ServletContext;
import org.apache.jasper.Constants;
import org.apache.jasper.JasperException;
import org.apache.tomcat.Jar;
import org.apache.tomcat.util.descriptor.tld.TaglibXml;
import org.apache.tomcat.util.descriptor.tld.TldParser;
import org.apache.tomcat.util.descriptor.tld.TldResourcePath;
import org.xml.sax.SAXException;
/**
* This class caches parsed instances of TLD files to remove the need for the
* same TLD to be parsed for each JSP that references it. It does not protect
* against multiple threads processing the same, new TLD but it does ensure that
* each all threads will use the same TLD object after parsing.
*/
public class TldCache {
public static final String SERVLET_CONTEXT_ATTRIBUTE_NAME =
TldCache.class.getName();
private final ServletContext servletContext;
private final Map uriTldResourcePathMap = new HashMap<>();
private final Map tldResourcePathTaglibXmlMap =
new HashMap<>();
private final TldParser tldParser;
public static TldCache getInstance(ServletContext servletContext) {
if (servletContext == null) {
throw new IllegalArgumentException(Localizer.getMessage(
"org.apache.jasper.compiler.TldCache.servletContextNull"));
}
return (TldCache) servletContext.getAttribute(SERVLET_CONTEXT_ATTRIBUTE_NAME);
}
public TldCache(ServletContext servletContext,
Map uriTldResourcePathMap,
Map tldResourcePathTaglibXmlMap) {
this.servletContext = servletContext;
this.uriTldResourcePathMap.putAll(uriTldResourcePathMap);
for (Entry entry : tldResourcePathTaglibXmlMap.entrySet()) {
TldResourcePath tldResourcePath = entry.getKey();
long lastModified[] = getLastModified(tldResourcePath);
TaglibXmlCacheEntry cacheEntry = new TaglibXmlCacheEntry(
entry.getValue(), lastModified[0], lastModified[1]);
this.tldResourcePathTaglibXmlMap.put(tldResourcePath, cacheEntry);
}
boolean validate = Boolean.parseBoolean(
servletContext.getInitParameter(Constants.XML_VALIDATION_TLD_INIT_PARAM));
String blockExternalString = servletContext.getInitParameter(
Constants.XML_BLOCK_EXTERNAL_INIT_PARAM);
boolean blockExternal;
if (blockExternalString == null) {
blockExternal = true;
} else {
blockExternal = Boolean.parseBoolean(blockExternalString);
}
tldParser = new TldParser(true, validate, blockExternal);
}
public TldResourcePath getTldResourcePath(String uri) {
return uriTldResourcePathMap.get(uri);
}
public TaglibXml getTaglibXml(TldResourcePath tldResourcePath) throws JasperException {
TaglibXmlCacheEntry cacheEntry = tldResourcePathTaglibXmlMap.get(tldResourcePath);
if (cacheEntry == null) {
return null;
}
long lastModified[] = getLastModified(tldResourcePath);
if (lastModified[0] != cacheEntry.getWebAppPathLastModified() ||
lastModified[1] != cacheEntry.getEntryLastModified()) {
synchronized (cacheEntry) {
if (lastModified[0] != cacheEntry.getWebAppPathLastModified() ||
lastModified[1] != cacheEntry.getEntryLastModified()) {
// Re-parse TLD
TaglibXml updatedTaglibXml;
try {
updatedTaglibXml = tldParser.parse(tldResourcePath);
} catch (IOException | SAXException e) {
throw new JasperException(e);
}
cacheEntry.setTaglibXml(updatedTaglibXml);
cacheEntry.setWebAppPathLastModified(lastModified[0]);
cacheEntry.setEntryLastModified(lastModified[1]);
}
}
}
return cacheEntry.getTaglibXml();
}
private long[] getLastModified(TldResourcePath tldResourcePath) {
long[] result = new long[2];
result[0] = -1;
result[1] = -1;
try {
String webappPath = tldResourcePath.getWebappPath();
if (webappPath != null) {
// webappPath will be null for JARs containing TLDs that are on
// the class path but not part of the web application
URL url = servletContext.getResource(tldResourcePath.getWebappPath());
URLConnection conn = url.openConnection();
result[0] = conn.getLastModified();
if ("file".equals(url.getProtocol())) {
// Reading the last modified time opens an input stream so we
// need to make sure it is closed again otherwise the TLD file
// will be locked until GC runs.
conn.getInputStream().close();
}
}
try (Jar jar = tldResourcePath.openJar()) {
if (jar != null) {
result[1] = jar.getLastModified(tldResourcePath.getEntryName());
}
}
} catch (IOException e) {
// Ignore (shouldn't happen)
}
return result;
}
private static class TaglibXmlCacheEntry {
private volatile TaglibXml taglibXml;
private volatile long webAppPathLastModified;
private volatile long entryLastModified;
TaglibXmlCacheEntry(TaglibXml taglibXml, long webAppPathLastModified,
long entryLastModified) {
this.taglibXml = taglibXml;
this.webAppPathLastModified = webAppPathLastModified;
this.entryLastModified = entryLastModified;
}
public TaglibXml getTaglibXml() {
return taglibXml;
}
public void setTaglibXml(TaglibXml taglibXml) {
this.taglibXml = taglibXml;
}
public long getWebAppPathLastModified() {
return webAppPathLastModified;
}
public void setWebAppPathLastModified(long webAppPathLastModified) {
this.webAppPathLastModified = webAppPathLastModified;
}
public long getEntryLastModified() {
return entryLastModified;
}
public void setEntryLastModified(long entryLastModified) {
this.entryLastModified = entryLastModified;
}
}
}