Google Git
Sign in
apache / cocoon / 3698825a003969178d0988bcce138586635b9400 / . / RELEASE_2_1_13 / src / java / org / apache / cocoon / transformation / IncludeTransformer.java
blob: 6d8be359857ea804200be1b0069db014308205fc [file] [log] [blame]
/*
* 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.cocoon.transformation;
import org.apache.avalon.framework.CascadingRuntimeException;
import org.apache.avalon.framework.component.WrapperComponentManager;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.logger.Logger;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.Processor;
import org.apache.cocoon.caching.CacheableProcessingComponent;
import org.apache.cocoon.components.CocoonComponentManager;
import org.apache.cocoon.components.source.SourceUtil;
import org.apache.cocoon.components.source.impl.MultiSourceValidity;
import org.apache.cocoon.components.thread.RunnableManager;
import org.apache.cocoon.environment.Environment;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.transformation.helpers.NOPRecorder;
import org.apache.cocoon.util.NetUtils;
import org.apache.cocoon.xml.AbstractXMLPipe;
import org.apache.cocoon.xml.IncludeXMLConsumer;
import org.apache.cocoon.xml.NamespacesTable;
import org.apache.cocoon.xml.SaxBuffer;
import org.apache.cocoon.xml.XMLConsumer;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceValidity;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;
import java.io.IOException;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;
import java.util.Stack;
/**
* <p>A simple transformer including resolvable sources (accessed through
* Cocoon's {@link SourceResolver}) from its input.</p>
*
* <p>Inclusion is triggered by the <code>&lt;include ... /&gt;</code> element
* defined in the <code>http://apache.org/cocoon/include/1.0</code> namespace.</p>
*
* <p>Example:</p>
* <pre>
* &lt;i:include xmlns:i="http://apache.org/cocoon/include/1.0"
* src="cocoon://path/to/include"/&gt;
* </pre>
*
* <p>An interesting feature of this {@link Transformer} is that it implements the
* {@link CacheableProcessingComponent} interface and provides full support for
* caching. In other words, if the input given to this transformer has not changed,
* and all of the included sources are (cacheable) and still valid, this transformer
* will not force a pipeline re-generation like the {@link CIncludeTransformer}.</p>
*
*
* <h3>Relative Source Resolution</h3>
* <p>Include sources which are specified using relative URI will be resolved
* relative to the source document location. This is consistent with
* {@link XIncludeTransformer} behavior, but differs from {@link CIncludeTransformer}.
*
* <h3>Root Element Stripping</h3>
* <p>The root element of included content may be automatically stripped by specifying
* <code>strip-root="true"</code> on the <code>include</code> element. This is the same
* functionality as provided by {@link org.apache.cocoon.transformation.CIncludeTransformer}.
* Setting <ode>strip-root="true"</code> has no effect if recursive processing is enabled.
* </p>
*
* <p>Example:</p>
* <pre>
* &lt;i:include xmlns:i="http://apache.org/cocoon/include/1.0"
* src="cocoon://path/to/include" strip-root="true"/&gt;
* </pre>
*
* <h3>Parameters Passing</h3>
* <p>Parameters to be passed to the included sources can be specified in two ways:
* the first one is to encode them onto the source itelf, for example:</p>
*
* <pre>
* &lt;i:include xmlns:i="http://apache.org/cocoon/include/1.0"
* src="cocoon://path/to/include?paramA=valueA&amp;paramB=valueB"/&gt;
* </pre>
*
* <p>Another approach allows the encoding of parameters to be done automatically by
* the transformer, so that one can easily pass parameter name or values containing
* the <code>&amp;</code> (amperstand) or <code>=</code> (equals) character, which are
* reserved characters in URIs. An example:</p>
*
* <pre>
* &lt;i:include xmlns:i="http://apache.org/cocoon/include/1.0"
* src="cocoon://path/to/include"&gt;
* &lt;i:parameter name="firstParameterName" value="firstParameterValue"/&gt;
* &lt;i:parameter name="other&amp;Para=Name" value="other=Para&amp;Value"/&gt;
* &lt;/i:include&gt;
* </pre>
*
*
* <h3>Fallback Element</h3>
* <p>IncludeTransformer allows fallback element to be specified within
* include element. XML content of the fallback element will be included instead
* of source content if source inclusion caused an exception. Fallback element
* can have nested include elements. An example:</p>
*
* <pre>
* &lt;i:include xmlns:i="http://apache.org/cocoon/include/1.0"
* src="cocoon://path/to/include"&gt;
* &lt;i:fallback&gt;
* <strong>The data is temporarily unavailable.</strong>
* We are sorry for the trouble; please try again later.
* &lt;/i:fallback&gt;
* &lt;/i:include&gt;
* </pre>
*
*
* <h3>Parallel Processing</h3>
* <p>Another feature of this {@link Transformer} is that it allows parallel processing
* of includes. By setting the optional parameter <code>parallel</code> to true,
* the various included contents are processed (included) in parallel threads rather
* than in series, in one thread. This parameter can be set in either the transformer
* definition (to affect all IncludeTransformer instances):</p>
* <pre>
* &lt;parallel&gt;true&lt;/parallel&gt;
* </pre>
*
* <p>or in a pipeline itself (to only affect that instance of the IncludeTransformer):</p>
* <pre>
* &lt;map:parameter name="parallel" value="true"/&gt;
* </pre>
* <p>By default, parallel processing is turned off.</p>
*
*
* <h3>Recursive Processing</h3>
* <p>This {@link Transformer} allows recursive processing of includes.
* By setting the optional parameter <code>recursive</code> to true,
* the various included contents are scanned for include elements, and processed
* in the same manner as incoming XML events. This parameter can be set in either
* the transformer definition (to affect all IncludeTransformer instances):</p>
* <pre>
* &lt;recursive&gt;true&lt;/recursive&gt;
* </pre>
*
* <p>or in a pipeline itself (to only affect that instance of the IncludeTransformer):</p>
* <pre>
* &lt;map:parameter name="recursive" value="true"/&gt;
* </pre>
* <p>This feature is similar to the XInclude processing. By default,
* recursive processing is turned off.</p>
*
*
* @cocoon.sitemap.component.documentation
* A simple transformer including resolvable sources (accessed through
* Cocoon's SourceResolver) from its input.
*
* @cocoon.sitemap.component.name include
* @cocoon.sitemap.component.logger sitemap.transformer.include
* @cocoon.sitemap.component.pooling.max 16
* @version $Id$
*/
public class IncludeTransformer extends AbstractTransformer
implements Serviceable, Configurable,
CacheableProcessingComponent {
/** <p>The namespace URI of the elements recognized by this transformer.</p> */
private static final String NS_URI = "http://apache.org/cocoon/include/1.0";
/** <p>The name of the element triggering inclusion of sources.</p> */
private static final String INCLUDE_ELEMENT = "include";
/** <p>The name of the element defining a fallback content.</p> */
private static final String FALLBACK_ELEMENT = "fallback";
/** <p>The name of the element defining an included subrequest parameter.</p> */
private static final String PARAMETER_ELEMENT = "parameter";
/** <p>The name of the attribute indicating the included source URI.</p> */
private static final String SRC_ATTRIBUTE = "src";
/** <p>The name of the mime type attribute containing the hint for the {@link org.apache.excalibur.xmlizer.XMLizer}.</p> */
private static final String MIME_ATTRIBUTE = "mime-type";
/** <p>The name of the parse attribute indicating type of included source processing: xml or text.</p> */
private static final String PARSE_ATTRIBUTE = "parse";
/** <p>The name of the strip-root attribute indicating that the root element of included xml source should be stripped.</p> */
private static final String STRIP_ROOT_ATTRIBUTE = "strip-root";
/** <p>The name of the attribute indicating the parameter name.</p> */
private static final String NAME_ATTRIBUTE = "name";
/** <p>The name of the attribute indicating the parameter name.</p> */
private static final String VALUE_ATTRIBUTE = "value";
/** <p>The encoding to use for parameter names and values.</p> */
private static final String ENCODING = "US-ASCII";
//
// Global configuration
//
/** The {@link ServiceManager} instance associated with this instance. */
protected ServiceManager manager;
/** Configuration option controlling recursive includes processing */
private boolean defaultRecursive;
/** Configuration option controlling parallel (in multiple threads) includes processing */
private boolean defaultParallel;
/** Configuration option controlling parallel (in multiple threads) includes processing in the recursive includes */
private boolean defaultRecursiveParallel;
/** The name of the thread pool to use (for parallel processing). */
protected String threadPool;
/** The default value to be appended to the caching key. */
private String defaultKey;
//
// Current configuration
//
/** The {@link SourceResolver} used to resolve included URIs. */
protected SourceResolver resolver;
/** The {@link Environment} used within parallel threads */
protected Environment environment;
/** The {@link Processor} used within parallel threads */
private Processor processor;
/** The value to be appended to the caching key. */
private String key;
//
// Current state
//
/** The {@link SourceValidity} instance associated with this request. */
protected MultiSourceValidity validity;
/** A {@link NamespacesTable} used to filter namespace declarations. */
private NamespacesTable namespaces;
/** The {@link IncludeXMLPipe} which is doing all the work */
private final IncludeXMLPipe pipe;
/**
* <p>Create a new {@link IncludeTransformer} instance.</p>
*/
public IncludeTransformer() {
pipe = new IncludeXMLPipe();
}
/**
* <p>Initialize own and {@link #pipe} loggers</p>
*/
public void enableLogging(Logger logger) {
super.enableLogging(logger);
pipe.enableLogging(logger);
}
/**
* <p>Setup the {@link ServiceManager} available for this instance.</p>
*
* @see Serviceable#service(ServiceManager)
*/
public void service(ServiceManager manager) throws ServiceException {
this.manager = manager;
}
/* (non-Javadoc)
* @see Configurable#configure(Configuration)
*/
public void configure(Configuration configuration) throws ConfigurationException {
/* Read configuration nodes for recursive, parallel, recursive-parallel */
this.defaultRecursive = configuration.getChild("recursive").getValueAsBoolean(false);
this.defaultParallel = configuration.getChild("parallel").getValueAsBoolean(false);
this.defaultRecursiveParallel = configuration.getChild("recursive-parallel").getValueAsBoolean(false);
/* Read configuration node for thread pool name */
this.threadPool = configuration.getChild("thread-pool").getValue("default");
this.defaultKey = configuration.getChild("key").getValue(null);
}
/**
* <p>Setup this component instance in the context of its pipeline and
* current request.</p>
*
* @see Serviceable#service(ServiceManager)
*/
public void setup(SourceResolver resolver, Map om, String src, Parameters parameters)
throws ProcessingException, SAXException, IOException {
/* Read sitemap parameters */
this.pipe.recursive = parameters.getParameterAsBoolean("recursive", this.defaultRecursive);
this.pipe.parallel = parameters.getParameterAsBoolean("parallel", this.defaultParallel);
this.pipe.recursiveParallel = parameters.getParameterAsBoolean("recursive-parallel", this.defaultRecursiveParallel);
this.key = parameters.getParameter("key", this.defaultKey);
/* Init transformer state */
if (this.pipe.parallel) {
this.environment = CocoonComponentManager.getCurrentEnvironment();
this.processor = CocoonComponentManager.getCurrentProcessor();
}
this.namespaces = new NamespacesTable();
this.resolver = resolver;
this.validity = null;
// Set root include pipe as consumer.
// Won't use setter methods here - they are overridden
super.xmlConsumer = pipe;
super.contentHandler = pipe;
super.lexicalHandler = pipe;
}
public void setConsumer(XMLConsumer consumer) {
pipe.setConsumer(consumer);
}
public void setContentHandler(ContentHandler handler) {
pipe.setContentHandler(handler);
}
public void setLexicalHandler(LexicalHandler handler) {
pipe.setLexicalHandler(handler);
}
/**
* <p>Recycle this component instance.</p>
*
* @see org.apache.avalon.excalibur.pool.Recyclable#recycle()
*/
public void recycle() {
this.namespaces = null;
this.validity = null;
/* Make sure all threads completed their work */
this.pipe.recycle();
// Resolver can be nulled out when all threads completed processing
// and released their Sources.
this.resolver = null;
super.recycle();
}
/**
* <p>Receive notification of the beginning of an XML document.</p>
*
* @see ContentHandler#startDocument
*/
public void startDocument()
throws SAXException {
/* Make sure that we have a validity while processing */
getValidity();
super.startDocument();
}
/**
* <p>Receive notification of the end of an XML document.</p>
*
* @see ContentHandler#startDocument()
*/
public void endDocument()
throws SAXException {
/* Make sure that the validity is "closed" at the end */
this.validity.close();
super.endDocument();
}
/**
* <p>Receive notification of the start of a prefix mapping.</p>
*
* <p>This transformer will remove all prefix mapping declarations for those
* prefixes associated with the <code>http://apache.org/cocoon/include/1.0</code>
* namespace.</p>
*
* @see org.xml.sax.ContentHandler#startPrefixMapping(String, String)
*/
public void startPrefixMapping(String prefix, String nsuri)
throws SAXException {
if (NS_URI.equals(nsuri)) {
/* Skipping mapping for the current prefix as it's ours */
this.namespaces.addDeclaration(prefix, nsuri);
} else {
/* Map the current prefix, as we don't know it */
super.startPrefixMapping(prefix, nsuri);
}
}
/**
* <p>Receive notification of the end of a prefix mapping.</p>
*
* <p>This transformer will remove all prefix mapping declarations for those
* prefixes associated with the <code>http://apache.org/cocoon/include/1.0</code>
* namespace.</p>
*
* @see org.xml.sax.ContentHandler#endPrefixMapping(java.lang.String)
*/
public void endPrefixMapping(String prefix)
throws SAXException {
if (NS_URI.equals(this.namespaces.getUri(prefix))) {
/* Skipping unmapping for the current prefix as it's ours */
this.namespaces.removeDeclaration(prefix);
} else {
/* Unmap the current prefix, as we don't know it */
super.endPrefixMapping(prefix);
}
}
/**
* <p>Return the caching key associated with this transformation.</p>
*
* <p>When including <code>cocoon://</code> sources with dynamic
* content depending on environment (request parameters, session attributes,
* etc), it makes sense to provide such environment values to the transformer
* to be included into the key using <code>key</code> sitemap parameter.</p>
*
* @see CacheableProcessingComponent#getKey()
*/
public Serializable getKey() {
/*
* In case of including "cocoon://" or other dynamic sources key
* ideally has to include ProcessingPipelineKey of the included
* "cocoon://" sources, but it's not possible as at this time
* we don't know yet which sources will get included into the
* response.
*
* Hence, javadoc recommends providing key using sitemap parameter.
*/
return key == null? "I": "I" + key;
}
/**
* <p>Generate (or return) the {@link SourceValidity} instance used to
* possibly validate cached generations.</p>
*
* @return a <b>non null</b> {@link SourceValidity}.
* @see org.apache.cocoon.caching.CacheableProcessingComponent#getValidity()
*/
public SourceValidity getValidity() {
if (validity == null) {
validity = new MultiSourceValidity(resolver, -1);
}
return validity;
}
/**
* Description of the include element
*/
private class IncludeElement extends AbstractLogEnabled {
/** Parameter controlling recursive includes processing */
private boolean recursive;
/** Parameter controlling parallel (in multiple threads) includes processing */
private boolean parallel;
/** Parameter controlling parallel (in multiple threads) includes processing in recursive includes */
private boolean recursiveParallel;
/** The source base URI. */
private String base;
/** The source URI to be included declared in an src attribute of the include element. */
protected String source;
/** The flag indicating whether source content has to be parsed into XML or included as text. */
protected boolean parse;
/** The mime type hint to the {@link org.apache.excalibur.xmlizer.XMLizer} when parsing the source content. */
protected String mimeType;
/** The flag indicating whether to strip the root element. */
private boolean stripRoot;
/** The buffer collecting fallback content. */
protected SaxBuffer fallback;
/** A {@link Map} of the parameters to supply to the included source. */
protected Map parameters;
/** The current parameter name captured. */
protected String parameter;
/** The current parameter value (as a {@link StringBuffer}). */
protected StringBuffer value;
/** Create include element */
private IncludeElement(String base, boolean parallel, boolean recursive, boolean recursiveParallel, Logger logger) {
this.base = base;
this.parallel = parallel;
this.recursive = recursive;
this.recursiveParallel = recursiveParallel;
this.enableLogging(logger);
}
/**
* Process element into the buffer.
* This can not be shared buffer, as it must be cleaned if fallback is invoked.
*/
public void process(SaxBuffer buffer)
throws SAXException {
try {
process0(buffer, buffer);
} catch (SAXException e) {
buffer.recycle();
if (this.fallback == null) {
throw e;
}
if (getLogger().isInfoEnabled()) {
getLogger().info("Failed to load <" + this.source + ">, using fallback.", e);
}
// Stream fallback through IncludeXMLPipe
this.fallback.toSAX(new IncludeXMLPipe(getLogger(), buffer, buffer,
recursive, recursiveParallel? parallel: false, recursiveParallel));
}
}
/** Load URI into the provided handlers, process fallback */
public void process(ContentHandler contentHandler, LexicalHandler lexicalHandler)
throws SAXException {
try {
if (this.fallback != null) {
SaxBuffer buffer = new SaxBuffer();
process(buffer);
buffer.toSAX(contentHandler);
} else {
process0(contentHandler, lexicalHandler);
}
} catch (SAXException e) {
// source must not be cached if an error occurs
validity = null;
throw e;
}
}
/** Load URI into the provided handlers. */
private void process0(ContentHandler contentHandler, LexicalHandler lexicalHandler)
throws SAXException {
Source source = null;
if (getLogger().isDebugEnabled()) {
getLogger().debug("Loading <" + this.source + ">");
}
// Setup this thread's environment
try {
if (base != null) {
source = resolver.resolveURI(this.source, base, null);
} else {
source = resolver.resolveURI(this.source);
}
if (validity != null) {
synchronized (validity) {
validity.addSource(source);
}
}
// Include source
if (this.parse && recursive) {
SourceUtil.toSAX(manager, source, this.mimeType,
new IncludeXMLPipe(getLogger(), contentHandler, lexicalHandler,
recursive, recursiveParallel? parallel: false, recursiveParallel));
} else if (this.parse) {
IncludeXMLConsumer includeXMLConsumer = new IncludeXMLConsumer(contentHandler, lexicalHandler);
includeXMLConsumer.setIgnoreRootElement(stripRoot);
SourceUtil.toSAX(manager, source, this.mimeType, includeXMLConsumer);
} else {
SourceUtil.toCharacters(source, "utf-8", contentHandler);
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("Loaded <" + this.source + ">");
}
} catch (SAXException e) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Failed to load <" + this.source + ">", e);
}
throw e;
} catch (ProcessingException e) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Failed to load <" + this.source + ">", e);
}
throw new SAXException(e);
} catch (IOException e) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Failed to load <" + this.source + ">", e);
}
throw new SAXException(e);
} finally {
if (source != null) {
resolver.release(source);
}
}
}
}
/**
* XML pipe reacting on the elements in the include namespace.
*/
private class IncludeXMLPipe extends AbstractXMLPipe {
//
// Configuration
//
/** Indicates whether this is root include pipe (owned by transformer) or a nested one */
private final boolean root;
/** Parameter controlling recursive includes processing */
private boolean recursive;
/** Parameter controlling parallel (in multiple threads) includes processing */
private boolean parallel;
/** Parameter controlling parallel (in multiple threads) includes processing in recursive includes */
private boolean recursiveParallel;
//
// Current state
//
/** Stack of {@link XMLConsumer}s */
private final Stack consumers = new Stack();
/** Current depth of nested elements in the include namespace */
private int depth;
/** Base URI used for the resolving included sources */
private String base;
/** The source to be included declared in an include element. */
private IncludeElement element;
/** If parallel processing is enabled, then this boolean tells us whether buffering has started yet. */
private boolean buffering;
/**
* <p>The IncludeBuffer that is used to buffering events if parallel
* processing is turned on.</p>
* <p>This object is also used as a lock for the thread counter <code>threads</code>.</p>
*/
private SaxBuffer buffer;
/** Inclusion threads/tasks counter (if executing in parallel) */
private int threads;
/**
* <p>Create a new {@link IncludeXMLPipe} instance.</p>
*/
public IncludeXMLPipe() {
root = true;
}
/**
* <p>Create a new {@link IncludeXMLPipe} instance.</p>
*/
public IncludeXMLPipe(Logger logger, ContentHandler contentHandler, LexicalHandler lexicalHandler,
boolean recursive, boolean parallel, boolean recursiveParallel) {
root = false;
this.enableLogging(logger);
this.setContentHandler(contentHandler);
this.setLexicalHandler(lexicalHandler);
this.recursive = recursive;
this.parallel = parallel;
this.recursiveParallel = recursiveParallel;
}
/**
* Finish processing.
*/
public void recycle() {
if (this.buffering) {
// Wait for threads to complete and release Sources
waitForThreads();
this.buffering = false;
this.buffer = null;
}
this.threads = 0;
this.consumers.clear();
this.base = null;
this.element = null;
super.recycle();
}
/** Push current consumer into the stack, replace with new one */
private void push(XMLConsumer consumer) {
this.consumers.push(new Object[]{ super.xmlConsumer, super.contentHandler, super.lexicalHandler });
this.setConsumer(consumer);
}
/** Pop consumer from the stack, replace current one */
private void pop() {
Object[] consumer = (Object[]) this.consumers.pop();
if (consumer[0] != null) {
this.setConsumer((XMLConsumer) consumer[0]);
} else {
this.setContentHandler((ContentHandler) consumer[1]);
this.setLexicalHandler((LexicalHandler) consumer[2]);
}
}
//
// ContentHandler interface
//
public void setDocumentLocator(Locator locator) {
try {
if (locator != null && locator.getSystemId() != null) {
Source source = resolver.resolveURI(locator.getSystemId());
try {
base = source.getURI();
} finally {
resolver.release(source);
}
}
} catch (IOException e) {
getLogger().warn("Unable to resolve document base URI: <" + locator.getSystemId() + ">");
}
super.setDocumentLocator(locator);
}
/**
* <p>Receive notification of the beginning of an XML document.</p>
* @see ContentHandler#startDocument
*/
public void startDocument() throws SAXException {
if (root) {
super.startDocument();
}
}
/**
* <p>Receive notification of the end of an XML document.</p>
* @see ContentHandler#startDocument
*/
public void endDocument() throws SAXException {
/* This is the end of the line - process the buffered events */
if (this.buffering) {
pop();
this.buffer.toSAX(super.contentHandler);
}
if (root) {
super.endDocument();
}
}
/**
* <p>Receive notification of the start of an element.</p>
* @see ContentHandler#startElement
*/
public void startElement(String uri, String localName, String qName, Attributes atts)
throws SAXException {
/* Check the namespace declaration */
if (NS_URI.equals(uri)) {
/*
* Depth 0: Outside of any include tag
* Depth 1: Must be Inside <include> tag
* Depth 2: Inside <fallback> tag
*/
depth++;
/* Inclusion will not happen here but when we close this tag */
if (INCLUDE_ELEMENT.equals(localName) && depth == 1) {
/* Check before we include (we don't want nested stuff) */
if (element != null) {
throw new SAXException("Element " + INCLUDE_ELEMENT + " nested in another one.");
}
element = new IncludeElement(this.base, this.parallel, this.recursive, this.recursiveParallel, getLogger());
/* Remember the source we are trying to include */
element.source = atts.getValue(SRC_ATTRIBUTE);
if (element.source == null || element.source.length() == 0) {
throw new SAXException("Attribute '" + SRC_ATTRIBUTE + "' empty or missing.");
}
/* Defaults to 'xml' */
String value = atts.getValue(PARSE_ATTRIBUTE);
if (value == null || value.equals("xml")) {
element.parse = true;
} else if (value.equals("text")) {
element.parse = false;
} else {
throw new SAXException("Attribute '" + PARSE_ATTRIBUTE + "' has invalid value.");
}
/* Defaults to 'text/xml' */
element.mimeType = atts.getValue(MIME_ATTRIBUTE);
if (!element.parse && element.mimeType != null) {
throw new SAXException("Attribute '" + MIME_ATTRIBUTE + "' can't be specified for text inclusions.");
} else if (element.mimeType == null) {
element.mimeType = "text/xml";
}
/* Defaults to false */
String stripRoot = atts.getValue(STRIP_ROOT_ATTRIBUTE);
element.stripRoot = Boolean.valueOf(stripRoot).booleanValue();
/* Ignore nested content */
push(new NOPRecorder(){});
/* Done with this element */
return;
}
/* If this is a fallback parameter, capture its content. */
if (FALLBACK_ELEMENT.equals(localName) && depth == 2) {
/* Check if we are in the right context */
if (element == null) {
throw new SAXException("Element " + FALLBACK_ELEMENT + " specified outside of " + INCLUDE_ELEMENT + ".");
}
if (element.fallback != null) {
throw new SAXException("Duplicate element " + FALLBACK_ELEMENT + ".");
}
/* Buffer fallback content */
push(element.fallback = new SaxBuffer());
/* Done with this element */
return;
}
/* If this is a parameter, then make sure we prepare. */
if (PARAMETER_ELEMENT.equals(localName) && depth == 2) {
/* Check if we are in the right context */
if (element == null) {
throw new SAXException("Element " + PARAMETER_ELEMENT + " specified outside of " + INCLUDE_ELEMENT + ".");
}
if (element.parameter != null) {
throw new SAXException("Element " + PARAMETER_ELEMENT + " nested in another one.");
}
/* Get and process the parameter name */
element.parameter = atts.getValue(NAME_ATTRIBUTE);
if (element.parameter == null || element.parameter.length() == 0) {
throw new SAXException("Attribute '" + NAME_ATTRIBUTE + "' empty or missing.");
}
/* Make some room for the parameter value */
String value = atts.getValue(VALUE_ATTRIBUTE);
if (value != null) {
element.value = new StringBuffer(value);
}
/* Done with this element */
return;
}
/* We don't have a clue of why we got here (wrong element?) */
if (depth < 2) {
throw new SAXException("Element '" + localName + "' was not expected here.");
}
}
super.startElement(uri, localName, qName, atts);
}
/**
* <p>Receive notification of the end of an element.</p>
* @see ContentHandler#endElement
*/
public void endElement(String uri, String localName, String qName)
throws SAXException {
/* Check the namespace declaration */
if (NS_URI.equals(uri)) {
/*
* Depth 0: Outside of any include tag
* Depth 1: Inside <include> tag
* Depth 2: Inside <fallback> tag
*/
depth--;
/* Inclusion will happen here, when we close the include element */
if (INCLUDE_ELEMENT.equals(localName) && depth == 0) {
/* End ignoring nested content */
pop();
/* Get the source discovered opening the element and include */
if (element.parameters != null) {
element.source = NetUtils.parameterize(element.source,
element.parameters);
element.parameters = null;
}
/* Check for parallel processing */
if (this.parallel) {
if (!this.buffering) {
this.buffering = true;
buffer = new SaxBuffer();
push(buffer);
}
/* Process include element in separate thread */
buffer.xmlizable(new IncludeBuffer(element));
} else {
/* Process include element inline */
element.process(super.contentHandler, super.lexicalHandler);
}
/* We are done with this include element */
this.element = null;
return;
}
if (FALLBACK_ELEMENT.equals(localName) && depth == 1) {
/* End buffering fallback content */
pop();
/* Done with this element */
return;
}
/* Addition of parameters happens here (so that we can capture chars) */
if (PARAMETER_ELEMENT.equals(localName) && depth == 1) {
String value = (element.value != null? element.value.toString(): "");
/* Store the parameter name and value */
try {
/*
* Note: the parameter name and value are URL encoded, so that
* weird characters such as "&" or "=" (have special meaning)
* are passed through flawlessly.
*/
if (element.parameters == null) {
element.parameters = new HashMap(5);
}
element.parameters.put(NetUtils.encode(element.parameter, ENCODING),
NetUtils.encode(value, ENCODING));
} catch (UnsupportedEncodingException e) {
throw new SAXException("Your platform does not support the " +
ENCODING + " encoding", e);
}
/* We are done with this parameter element */
element.value = null;
element.parameter = null;
return;
}
}
/* This is not our namespace, pass the event on! */
super.endElement(uri, localName, qName);
}
/**
* <p>Receive notification of characters.</p>
* @see ContentHandler#characters
*/
public void characters(char[] data, int offset, int length)
throws SAXException {
if (element != null && element.parameter != null) {
/* If we have a parameter value to add to, let's add this chunk */
if (element.value == null) {
element.value = new StringBuffer();
}
element.value.append(data, offset, length);
return;
}
/* Forward */
super.characters(data, offset, length);
}
//
// Thread management
//
/**
* Increment active threads counter
*/
int incrementThreads() {
synchronized (buffer) {
return ++threads;
}
}
/**
* Decrement active threads counter
*/
void decrementThreads() {
synchronized (buffer) {
if (--threads <= 0) {
buffer.notify();
}
}
}
/**
* Wait till there is no active threads
*/
private void waitForThreads() {
synchronized (buffer) {
if (threads > 0) {
if (getLogger().isDebugEnabled()) {
getLogger().debug(threads + " threads in progress, waiting");
}
try {
buffer.wait();
} catch (InterruptedException e) { /* ignored */ }
// Don't continue waiting if interrupted.
}
}
}
/**
* Buffer for loading included source in separate thread.
* Streaming of the loaded buffer possible only when source is
* loaded completely. If loading is not complete, toSAX method
* will block.
*/
private class IncludeBuffer extends SaxBuffer
implements Runnable {
private IncludeElement element;
private int thread;
private boolean finished;
private SAXException e;
public IncludeBuffer(IncludeElement element) {
this.element = element;
RunnableManager runnable = null;
try {
runnable = (RunnableManager) IncludeTransformer.this.manager.lookup(RunnableManager.ROLE);
runnable.execute(IncludeTransformer.this.threadPool, this);
} catch (final ServiceException e) {
// In case we failed to spawn a thread
throw new CascadingRuntimeException(e.getMessage(), e);
} finally {
IncludeTransformer.this.manager.release(runnable);
}
// Increment active threads counter
this.thread = incrementThreads();
}
/**
* Load content of the source into this buffer.
*/
public void run() {
try {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Thread #" + thread + " loading <" + element.source + ">");
}
// Setup this thread's environment
CocoonComponentManager.enterEnvironment(environment, new WrapperComponentManager(manager), processor);
try {
element.process(this);
} catch (SAXException e) {
this.e = e;
} finally {
CocoonComponentManager.leaveEnvironment();
}
} catch (RuntimeException e) {
/* Unable to set thread's environment */
this.e = new SAXException(e);
} finally {
synchronized (this) {
this.finished = true;
notify();
}
// Make sure that active threads counter is decremented
decrementThreads();
}
if (getLogger().isDebugEnabled()) {
if (this.e == null) {
getLogger().debug("Thread #" + thread + " loaded <" + element.source + ">");
} else {
getLogger().debug("Thread #" + thread + " failed to load <" + element.source + ">", this.e);
}
}
}
/**
* Stream content of this buffer when it is loaded completely.
* This method blocks if loading is not complete.
*/
public void toSAX(ContentHandler contentHandler)
throws SAXException {
synchronized (this) {
if (!this.finished) {
try {
wait();
} catch (InterruptedException e) { /* ignored */ }
// Don't continue waiting if interrupted.
}
}
if (this.e != null) {
throw this.e;
}
super.toSAX(contentHandler);
}
}
}
}