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The Core Camel Java DSL based router
/**
* 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.camel.builder.xml;
import java.io.File;
import java.io.InputStream;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Queue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import javax.xml.namespace.QName;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXSource;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import javax.xml.xpath.XPathFactoryConfigurationException;
import javax.xml.xpath.XPathFunction;
import javax.xml.xpath.XPathFunctionException;
import javax.xml.xpath.XPathFunctionResolver;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.apache.camel.CamelContext;
import org.apache.camel.CamelContextAware;
import org.apache.camel.Exchange;
import org.apache.camel.Expression;
import org.apache.camel.NoTypeConversionAvailableException;
import org.apache.camel.Predicate;
import org.apache.camel.RuntimeExpressionException;
import org.apache.camel.WrappedFile;
import org.apache.camel.converter.jaxp.ThreadSafeNodeList;
import org.apache.camel.impl.DefaultExchange;
import org.apache.camel.spi.Language;
import org.apache.camel.spi.NamespaceAware;
import org.apache.camel.support.ServiceSupport;
import org.apache.camel.util.ExchangeHelper;
import org.apache.camel.util.IOHelper;
import org.apache.camel.util.MessageHelper;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.camel.builder.xml.Namespaces.DEFAULT_NAMESPACE;
import static org.apache.camel.builder.xml.Namespaces.FUNCTION_NAMESPACE;
import static org.apache.camel.builder.xml.Namespaces.IN_NAMESPACE;
import static org.apache.camel.builder.xml.Namespaces.OUT_NAMESPACE;
import static org.apache.camel.builder.xml.Namespaces.isMatchingNamespaceOrEmptyNamespace;
/**
* Creates an XPath expression builder which creates a nodeset result by default.
* If you want to evaluate a String expression then call {@link #stringResult()}
*
* An XPath object is not thread-safe and not reentrant. In other words, it is the application's responsibility to make
* sure that one XPath object is not used from more than one thread at any given time, and while the evaluate method
* is invoked, applications may not recursively call the evaluate method.
*
* This implementation is thread safe by using thread locals and pooling to allow concurrency.
*
* Important: After configuring the {@link XPathBuilder} its advised to invoke {@link #start()}
* to prepare the builder before using; though the builder will auto-start on first use.
*
* @see XPathConstants#NODESET
*/
public class XPathBuilder extends ServiceSupport implements CamelContextAware, Expression, Predicate, NamespaceAware {
private static final Logger LOG = LoggerFactory.getLogger(XPathBuilder.class);
private static final String SAXON_OBJECT_MODEL_URI = "http://saxon.sf.net/jaxp/xpath/om";
private static final String SAXON_FACTORY_CLASS_NAME = "net.sf.saxon.xpath.XPathFactoryImpl";
private static final String OBTAIN_ALL_NS_XPATH = "//*/namespace::*";
private static volatile XPathFactory defaultXPathFactory;
private CamelContext camelContext;
private final Queue pool = new ConcurrentLinkedQueue();
private final Queue poolLogNamespaces = new ConcurrentLinkedQueue();
private final String text;
private final ThreadLocal exchange = new ThreadLocal();
private final MessageVariableResolver variableResolver = new MessageVariableResolver(exchange);
private final Map namespaces = new ConcurrentHashMap();
private boolean threadSafety;
private volatile XPathFactory xpathFactory;
private volatile Class documentType = Document.class;
// For some reason the default expression of "a/b" on a document such as
// 12
// will evaluate as just "1" by default which is bizarre. So by default
// let's assume XPath expressions result in nodesets.
private volatile Class resultType;
private volatile QName resultQName = XPathConstants.NODESET;
private volatile String objectModelUri;
private volatile String factoryClassName;
private volatile DefaultNamespaceContext namespaceContext;
private volatile boolean logNamespaces;
private volatile XPathFunctionResolver functionResolver;
private volatile XPathFunction bodyFunction;
private volatile XPathFunction headerFunction;
private volatile XPathFunction outBodyFunction;
private volatile XPathFunction outHeaderFunction;
private volatile XPathFunction propertiesFunction;
private volatile XPathFunction simpleFunction;
/**
* The name of the header we want to apply the XPath expression to, which when set will cause
* the xpath to be evaluated on the required header, otherwise it will be applied to the body
*/
private volatile String headerName;
/**
* @param text The XPath expression
*/
public XPathBuilder(String text) {
this.text = text;
}
/**
* @param text The XPath expression
* @return A new XPathBuilder object
*/
public static XPathBuilder xpath(String text) {
return new XPathBuilder(text);
}
/**
* @param text The XPath expression
* @param resultType The result type that the XPath expression will return.
* @return A new XPathBuilder object
*/
public static XPathBuilder xpath(String text, Class resultType) {
XPathBuilder builder = new XPathBuilder(text);
builder.setResultType(resultType);
return builder;
}
@Override
public String toString() {
return "XPath: " + text;
}
@Override
public CamelContext getCamelContext() {
return camelContext;
}
@Override
public void setCamelContext(CamelContext camelContext) {
this.camelContext = camelContext;
}
public boolean matches(Exchange exchange) {
try {
Object booleanResult = evaluateAs(exchange, XPathConstants.BOOLEAN);
return exchange.getContext().getTypeConverter().convertTo(Boolean.class, booleanResult);
} finally {
// remove the thread local after usage
this.exchange.remove();
}
}
public T evaluate(Exchange exchange, Class type) {
try {
Object result = evaluate(exchange);
return exchange.getContext().getTypeConverter().convertTo(type, exchange, result);
} finally {
// remove the thread local after usage
this.exchange.remove();
}
}
/**
* Matches the given xpath using the provided body.
*
* @param context the camel context
* @param body the body
* @return true if matches, false otherwise
*/
public boolean matches(CamelContext context, Object body) {
ObjectHelper.notNull(context, "CamelContext");
// create a dummy Exchange to use during matching
Exchange dummy = new DefaultExchange(context);
dummy.getIn().setBody(body);
try {
return matches(dummy);
} finally {
// remove the thread local after usage
exchange.remove();
}
}
/**
* Evaluates the given xpath using the provided body.
*
* The evaluation uses by default {@link javax.xml.xpath.XPathConstants#NODESET} as the type
* used during xpath evaluation. The output from xpath is then afterwards type converted
* using Camel's type converter to the given type.
*
* If you want to evaluate xpath using a different type, then call {@link #setResultType(Class)}
* prior to calling this evaluate method.
*
* @param context the camel context
* @param body the body
* @param type the type to return
* @return result of the evaluation
*/
public T evaluate(CamelContext context, Object body, Class type) {
ObjectHelper.notNull(context, "CamelContext");
// create a dummy Exchange to use during evaluation
Exchange dummy = new DefaultExchange(context);
dummy.getIn().setBody(body);
try {
return evaluate(dummy, type);
} finally {
// remove the thread local after usage
exchange.remove();
}
}
/**
* Evaluates the given xpath using the provided body as a String return type.
*
* @param context the camel context
* @param body the body
* @return result of the evaluation
*/
public String evaluate(CamelContext context, Object body) {
ObjectHelper.notNull(context, "CamelContext");
// create a dummy Exchange to use during evaluation
Exchange dummy = new DefaultExchange(context);
dummy.getIn().setBody(body);
setResultQName(XPathConstants.STRING);
setResultType(String.class);
try {
return evaluate(dummy, String.class);
} finally {
// remove the thread local after usage
this.exchange.remove();
}
}
// Builder methods
// -------------------------------------------------------------------------
/**
* Sets the expression result type to {@link XPathConstants#BOOLEAN}
*
* @return the current builder
*/
public XPathBuilder booleanResult() {
resultQName = XPathConstants.BOOLEAN;
return this;
}
/**
* Sets the expression result type to {@link XPathConstants#NODE}
*
* @return the current builder
*/
public XPathBuilder nodeResult() {
resultQName = XPathConstants.NODE;
return this;
}
/**
* Sets the expression result type to {@link XPathConstants#NODESET}
*
* @return the current builder
*/
public XPathBuilder nodeSetResult() {
resultQName = XPathConstants.NODESET;
return this;
}
/**
* Sets the expression result type to {@link XPathConstants#NUMBER}
*
* @return the current builder
*/
public XPathBuilder numberResult() {
resultQName = XPathConstants.NUMBER;
return this;
}
/**
* Sets the expression result type to {@link XPathConstants#STRING}
*
* @return the current builder
*/
public XPathBuilder stringResult() {
resultQName = XPathConstants.STRING;
return this;
}
/**
* Sets the expression result type to the given {@code resultType}
*
* @return the current builder
*/
public XPathBuilder resultType(Class resultType) {
setResultType(resultType);
return this;
}
/**
* Sets the object model URI to use
*
* @return the current builder
*/
public XPathBuilder objectModel(String uri) {
// Careful! Setting the Object Model URI this way will set the *Default* XPath Factory, which since is a static field,
// will set the XPath Factory system-wide. Decide what to do, as changing this behaviour can break compatibility. Provided the setObjectModel which changes
// this instance's XPath Factory rather than the static field
this.objectModelUri = uri;
return this;
}
/**
* Sets the factory class name to use
*
* @return the current builder
*/
public XPathBuilder factoryClassName(String factoryClassName) {
this.factoryClassName = factoryClassName;
return this;
}
/**
* Configures to use Saxon as the XPathFactory which allows you to use XPath 2.0 functions
* which may not be part of the build in JDK XPath parser.
*
* @return the current builder
*/
public XPathBuilder saxon() {
this.objectModelUri = SAXON_OBJECT_MODEL_URI;
this.factoryClassName = SAXON_FACTORY_CLASS_NAME;
return this;
}
/**
* Sets the {@link XPathFunctionResolver} instance to use on these XPath
* expressions
*
* @return the current builder
*/
public XPathBuilder functionResolver(XPathFunctionResolver functionResolver) {
this.functionResolver = functionResolver;
return this;
}
/**
* Registers the namespace prefix and URI with the builder so that the
* prefix can be used in XPath expressions
*
* @param prefix is the namespace prefix that can be used in the XPath
* expressions
* @param uri is the namespace URI to which the prefix refers
* @return the current builder
*/
public XPathBuilder namespace(String prefix, String uri) {
namespaces.put(prefix, uri);
return this;
}
/**
* Registers namespaces with the builder so that the registered
* prefixes can be used in XPath expressions
*
* @param namespaces is namespaces object that should be used in the
* XPath expression
* @return the current builder
*/
public XPathBuilder namespaces(Namespaces namespaces) {
namespaces.configure(this);
return this;
}
/**
* Registers a variable (in the global namespace) which can be referred to
* from XPath expressions
*
* @param name name of variable
* @param value value of variable
* @return the current builder
*/
public XPathBuilder variable(String name, Object value) {
getVariableResolver().addVariable(name, value);
return this;
}
/**
* Configures the document type to use.
*
* The document type controls which kind of Class Camel should convert the payload
* to before doing the xpath evaluation.
*
* For example you can set it to {@link InputSource} to use SAX streams.
* By default Camel uses {@link Document} as the type.
*
* @param documentType the document type
* @return the current builder
*/
public XPathBuilder documentType(Class documentType) {
setDocumentType(documentType);
return this;
}
/**
* Configures to use the provided XPath factory.
*
* Can be used to use Saxon instead of the build in factory from the JDK.
*
* @param xpathFactory the xpath factory to use
* @return the current builder.
*/
public XPathBuilder factory(XPathFactory xpathFactory) {
setXPathFactory(xpathFactory);
return this;
}
/**
* Activates trace logging of all discovered namespaces in the message - to simplify debugging namespace-related issues
*
* Namespaces are printed in Hashmap style {xmlns:prefix=[namespaceURI], xmlns:prefix=[namespaceURI]}.
*
* The implicit XML namespace is omitted (http://www.w3.org/XML/1998/namespace).
* XML allows for namespace prefixes to be redefined/overridden due to hierarchical scoping, i.e. prefix abc can be mapped to http://abc.com,
* and deeper in the document it can be mapped to http://def.com. When two prefixes are detected which are equal but are mapped to different
* namespace URIs, Camel will show all namespaces URIs it is mapped to in an array-style.
*
* This feature is disabled by default.
*
* @return the current builder.
*/
public XPathBuilder logNamespaces() {
setLogNamespaces(true);
return this;
}
/**
* Whether to enable thread-safety for the returned result of the xpath expression.
* This applies to when using NODESET as the result type, and the returned set has
* multiple elements. In this situation there can be thread-safety issues if you
* process the NODESET concurrently such as from a Camel Splitter EIP in parallel processing mode.
* This option prevents concurrency issues by doing defensive copies of the nodes.
*
* It is recommended to turn this option on if you are using camel-saxon or Saxon in your application.
* Saxon has thread-safety issues which can be prevented by turning this option on.
*
* Thread-safety is disabled by default
*
* @return the current builder.
*/
public XPathBuilder threadSafety(boolean threadSafety) {
setThreadSafety(threadSafety);
return this;
}
// Properties
// -------------------------------------------------------------------------
/**
* Gets the xpath factory, can be null if no custom factory has been assigned.
*
* A default factory will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the factory, or null if this builder has not been started/used before.
*/
public XPathFactory getXPathFactory() {
return xpathFactory;
}
public void setXPathFactory(XPathFactory xpathFactory) {
this.xpathFactory = xpathFactory;
}
public Class getDocumentType() {
return documentType;
}
public void setDocumentType(Class documentType) {
this.documentType = documentType;
}
public String getText() {
return text;
}
public QName getResultQName() {
return resultQName;
}
public void setResultQName(QName resultQName) {
this.resultQName = resultQName;
}
public String getHeaderName() {
return headerName;
}
public void setHeaderName(String headerName) {
this.headerName = headerName;
}
public boolean isThreadSafety() {
return threadSafety;
}
public void setThreadSafety(boolean threadSafety) {
this.threadSafety = threadSafety;
}
/**
* Gets the namespace context, can be null if no custom context has been assigned.
*
* A default context will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the context, or null if this builder has not been started/used before.
*/
public DefaultNamespaceContext getNamespaceContext() {
return namespaceContext;
}
public void setNamespaceContext(DefaultNamespaceContext namespaceContext) {
this.namespaceContext = namespaceContext;
}
public XPathFunctionResolver getFunctionResolver() {
return functionResolver;
}
public void setFunctionResolver(XPathFunctionResolver functionResolver) {
this.functionResolver = functionResolver;
}
public void setNamespaces(Map namespaces) {
this.namespaces.clear();
this.namespaces.putAll(namespaces);
}
public Map getNamespaces() {
return namespaces;
}
/**
* Gets the {@link XPathFunction} for getting the input message body.
*
* A default function will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the function, or null if this builder has not been started/used before.
*/
public XPathFunction getBodyFunction() {
return bodyFunction;
}
private XPathFunction createBodyFunction() {
return new XPathFunction() {
@SuppressWarnings("rawtypes")
public Object evaluate(List list) throws XPathFunctionException {
return exchange.get().getIn().getBody();
}
};
}
public void setBodyFunction(XPathFunction bodyFunction) {
this.bodyFunction = bodyFunction;
}
/**
* Gets the {@link XPathFunction} for getting the input message header.
*
* A default function will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the function, or null if this builder has not been started/used before.
*/
public XPathFunction getHeaderFunction() {
return headerFunction;
}
private XPathFunction createHeaderFunction() {
return new XPathFunction() {
@SuppressWarnings("rawtypes")
public Object evaluate(List list) throws XPathFunctionException {
if (!list.isEmpty()) {
Object value = list.get(0);
if (value != null) {
String text = exchange.get().getContext().getTypeConverter().convertTo(String.class, value);
return exchange.get().getIn().getHeader(text);
}
}
return null;
}
};
}
public void setHeaderFunction(XPathFunction headerFunction) {
this.headerFunction = headerFunction;
}
/**
* Gets the {@link XPathFunction} for getting the output message body.
*
* A default function will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the function, or null if this builder has not been started/used before.
*/
public XPathFunction getOutBodyFunction() {
return outBodyFunction;
}
private XPathFunction createOutBodyFunction() {
return new XPathFunction() {
@SuppressWarnings("rawtypes")
public Object evaluate(List list) throws XPathFunctionException {
if (exchange.get() != null && exchange.get().hasOut()) {
return exchange.get().getOut().getBody();
}
return null;
}
};
}
public void setOutBodyFunction(XPathFunction outBodyFunction) {
this.outBodyFunction = outBodyFunction;
}
/**
* Gets the {@link XPathFunction} for getting the output message header.
*
* A default function will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the function, or null if this builder has not been started/used before.
*/
public XPathFunction getOutHeaderFunction() {
return outHeaderFunction;
}
private XPathFunction createOutHeaderFunction() {
return new XPathFunction() {
@SuppressWarnings("rawtypes")
public Object evaluate(List list) throws XPathFunctionException {
if (exchange.get() != null && !list.isEmpty()) {
Object value = list.get(0);
if (value != null) {
String text = exchange.get().getContext().getTypeConverter().convertTo(String.class, value);
return exchange.get().getOut().getHeader(text);
}
}
return null;
}
};
}
public void setOutHeaderFunction(XPathFunction outHeaderFunction) {
this.outHeaderFunction = outHeaderFunction;
}
/**
* Gets the {@link XPathFunction} for getting the exchange properties.
*
* A default function will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the function, or null if this builder has not been started/used before.
*/
public XPathFunction getPropertiesFunction() {
return propertiesFunction;
}
private XPathFunction createPropertiesFunction() {
return new XPathFunction() {
@SuppressWarnings("rawtypes")
public Object evaluate(List list) throws XPathFunctionException {
if (!list.isEmpty()) {
Object value = list.get(0);
if (value != null) {
String text = exchange.get().getContext().getTypeConverter().convertTo(String.class, value);
try {
// use the property placeholder resolver to lookup the property for us
Object answer = exchange.get().getContext().resolvePropertyPlaceholders("{{" + text + "}}");
return answer;
} catch (Exception e) {
throw new XPathFunctionException(e);
}
}
}
return null;
}
};
}
public void setPropertiesFunction(XPathFunction propertiesFunction) {
this.propertiesFunction = propertiesFunction;
}
/**
* Gets the {@link XPathFunction} for executing simple
* language as xpath function.
*
* A default function will be assigned (if no custom assigned) when either starting this builder
* or on first evaluation.
*
* @return the function, or null if this builder has not been started/used before.
*/
public XPathFunction getSimpleFunction() {
return simpleFunction;
}
private XPathFunction createSimpleFunction() {
return new XPathFunction() {
@SuppressWarnings("rawtypes")
public Object evaluate(List list) throws XPathFunctionException {
if (!list.isEmpty()) {
Object value = list.get(0);
if (value != null) {
String text = exchange.get().getContext().getTypeConverter().convertTo(String.class, value);
Language simple = exchange.get().getContext().resolveLanguage("simple");
Expression exp = simple.createExpression(text);
Object answer = exp.evaluate(exchange.get(), Object.class);
return answer;
}
}
return null;
}
};
}
public void setSimpleFunction(XPathFunction simpleFunction) {
this.simpleFunction = simpleFunction;
}
public Class getResultType() {
return resultType;
}
public void setResultType(Class resultType) {
this.resultType = resultType;
if (Number.class.isAssignableFrom(resultType)) {
numberResult();
} else if (String.class.isAssignableFrom(resultType)) {
stringResult();
} else if (Boolean.class.isAssignableFrom(resultType)) {
booleanResult();
} else if (Node.class.isAssignableFrom(resultType)) {
nodeResult();
} else if (NodeList.class.isAssignableFrom(resultType)) {
nodeSetResult();
}
}
public void setLogNamespaces(boolean logNamespaces) {
this.logNamespaces = logNamespaces;
}
public boolean isLogNamespaces() {
return logNamespaces;
}
/**
* Enables Saxon on this particular XPath expression, as {@link #saxon()} sets the default static XPathFactory which may have already been initialised
* by previous XPath expressions
*/
public void enableSaxon() {
this.setObjectModelUri(SAXON_OBJECT_MODEL_URI);
this.setFactoryClassName(SAXON_FACTORY_CLASS_NAME);
}
public String getObjectModelUri() {
return objectModelUri;
}
public void setObjectModelUri(String objectModelUri) {
this.objectModelUri = objectModelUri;
}
public String getFactoryClassName() {
return factoryClassName;
}
public void setFactoryClassName(String factoryClassName) {
this.factoryClassName = factoryClassName;
}
// Implementation methods
// -------------------------------------------------------------------------
protected Object evaluate(Exchange exchange) {
Object answer = evaluateAs(exchange, resultQName);
if (resultType != null) {
return ExchangeHelper.convertToType(exchange, resultType, answer);
}
return answer;
}
/**
* Evaluates the expression as the given result type
*/
protected Object evaluateAs(Exchange exchange, QName resultQName) {
// pool a pre compiled expression from pool
XPathExpression xpathExpression = pool.poll();
if (xpathExpression == null) {
LOG.trace("Creating new XPathExpression as none was available from pool");
// no avail in pool then create one
try {
xpathExpression = createXPathExpression();
} catch (XPathExpressionException e) {
throw new InvalidXPathExpression(getText(), e);
} catch (Exception e) {
throw new RuntimeExpressionException("Cannot create xpath expression", e);
}
} else {
LOG.trace("Acquired XPathExpression from pool");
}
try {
if (logNamespaces && LOG.isInfoEnabled()) {
logNamespaces(exchange);
}
return doInEvaluateAs(xpathExpression, exchange, resultQName);
} finally {
// release it back to the pool
pool.add(xpathExpression);
LOG.trace("Released XPathExpression back to pool");
}
}
private void logNamespaces(Exchange exchange) {
InputStream is = null;
NodeList answer = null;
XPathExpression xpathExpression = null;
try {
xpathExpression = poolLogNamespaces.poll();
if (xpathExpression == null) {
xpathExpression = createTraceNamespaceExpression();
}
// prepare the input
Object document;
if (isInputStreamNeeded(exchange)) {
is = exchange.getIn().getBody(InputStream.class);
document = getDocument(exchange, is);
} else {
Object body = exchange.getIn().getBody();
document = getDocument(exchange, body);
}
// fetch all namespaces
if (document instanceof InputSource) {
InputSource inputSource = (InputSource) document;
answer = (NodeList) xpathExpression.evaluate(inputSource, XPathConstants.NODESET);
} else if (document instanceof DOMSource) {
DOMSource source = (DOMSource) document;
answer = (NodeList) xpathExpression.evaluate(source.getNode(), XPathConstants.NODESET);
} else if (document instanceof SAXSource) {
SAXSource source = (SAXSource) document;
// since its a SAXSource it may not return an NodeList (for example if using Saxon)
Object result = xpathExpression.evaluate(source.getInputSource(), XPathConstants.NODESET);
if (result instanceof NodeList) {
answer = (NodeList) result;
} else {
answer = null;
}
} else {
answer = (NodeList) xpathExpression.evaluate(document, XPathConstants.NODESET);
}
} catch (Exception e) {
LOG.warn("Unable to trace discovered namespaces in XPath expression", e);
} finally {
// IOHelper can handle if is is null
IOHelper.close(is);
poolLogNamespaces.add(xpathExpression);
}
if (answer != null) {
logDiscoveredNamespaces(answer);
}
}
private void logDiscoveredNamespaces(NodeList namespaces) {
Map> map = new LinkedHashMap>();
for (int i = 0; i < namespaces.getLength(); i++) {
Node n = namespaces.item(i);
if (n.getNodeName().equals("xmlns:xml")) {
// skip the implicit XML namespace as it provides no value
continue;
}
String prefix = namespaces.item(i).getNodeName();
if (prefix.equals("xmlns")) {
prefix = "DEFAULT";
}
// add to map
if (!map.containsKey(prefix)) {
map.put(prefix, new HashSet());
}
map.get(prefix).add(namespaces.item(i).getNodeValue());
}
LOG.info("Namespaces discovered in message: {}.", map);
}
protected Object doInEvaluateAs(XPathExpression xpathExpression, Exchange exchange, QName resultQName) {
LOG.trace("Evaluating exchange: {} as: {}", exchange, resultQName);
Object answer;
// set exchange and variable resolver as thread locals for concurrency
this.exchange.set(exchange);
// the underlying input stream, which we need to close to avoid locking files or other resources
InputStream is = null;
try {
Object document;
// Check if we need to apply the XPath expression to a header
if (ObjectHelper.isNotEmpty(getHeaderName())) {
String headerName = getHeaderName();
// only convert to input stream if really needed
if (isInputStreamNeeded(exchange, headerName)) {
is = exchange.getIn().getHeader(headerName, InputStream.class);
document = getDocument(exchange, is);
} else {
Object headerObject = exchange.getIn().getHeader(getHeaderName());
document = getDocument(exchange, headerObject);
}
} else {
// only convert to input stream if really needed
if (isInputStreamNeeded(exchange)) {
is = exchange.getIn().getBody(InputStream.class);
document = getDocument(exchange, is);
} else {
Object body = exchange.getIn().getBody();
document = getDocument(exchange, body);
}
}
if (resultQName != null) {
if (document instanceof InputSource) {
InputSource inputSource = (InputSource) document;
answer = xpathExpression.evaluate(inputSource, resultQName);
} else if (document instanceof DOMSource) {
DOMSource source = (DOMSource) document;
answer = xpathExpression.evaluate(source.getNode(), resultQName);
} else {
answer = xpathExpression.evaluate(document, resultQName);
}
} else {
if (document instanceof InputSource) {
InputSource inputSource = (InputSource) document;
answer = xpathExpression.evaluate(inputSource);
} else if (document instanceof DOMSource) {
DOMSource source = (DOMSource) document;
answer = xpathExpression.evaluate(source.getNode());
} else {
answer = xpathExpression.evaluate(document);
}
}
} catch (XPathExpressionException e) {
String message = getText();
if (ObjectHelper.isNotEmpty(getHeaderName())) {
message = message + " with headerName " + getHeaderName();
}
throw new InvalidXPathExpression(message, e);
} finally {
// IOHelper can handle if is is null
IOHelper.close(is);
}
if (threadSafety && answer != null && answer instanceof NodeList) {
try {
NodeList list = (NodeList) answer;
// when the result is NodeList and it has 2+ elements then its not thread-safe to use concurrently
// and we need to clone each node and build a thread-safe list to be used instead
boolean threadSafetyNeeded = list.getLength() >= 2;
if (threadSafetyNeeded) {
answer = new ThreadSafeNodeList(list);
if (LOG.isDebugEnabled()) {
LOG.debug("Created thread-safe result from: {} as: {}", list.getClass().getName(), answer.getClass().getName());
}
}
} catch (Exception e) {
throw ObjectHelper.wrapRuntimeCamelException(e);
}
}
if (LOG.isTraceEnabled()) {
LOG.trace("Done evaluating exchange: {} as: {} with result: {}", new Object[]{exchange, resultQName, answer});
}
return answer;
}
/**
* Creates a new xpath expression as there we no available in the pool.
*
* This implementation must be synchronized to ensure thread safety, as this XPathBuilder instance may not have been
* started prior to being used.
*/
protected synchronized XPathExpression createXPathExpression() throws XPathExpressionException, XPathFactoryConfigurationException {
// ensure we are started
try {
start();
} catch (Exception e) {
throw new RuntimeExpressionException("Error starting XPathBuilder", e);
}
// XPathFactory is not thread safe
XPath xPath = getXPathFactory().newXPath();
if (!logNamespaces && LOG.isTraceEnabled()) {
LOG.trace("Creating new XPath expression in pool. Namespaces on XPath expression: {}", getNamespaceContext().toString());
} else if (logNamespaces && LOG.isInfoEnabled()) {
LOG.info("Creating new XPath expression in pool. Namespaces on XPath expression: {}", getNamespaceContext().toString());
}
xPath.setNamespaceContext(getNamespaceContext());
xPath.setXPathVariableResolver(getVariableResolver());
XPathFunctionResolver parentResolver = getFunctionResolver();
if (parentResolver == null) {
parentResolver = xPath.getXPathFunctionResolver();
}
xPath.setXPathFunctionResolver(createDefaultFunctionResolver(parentResolver));
return xPath.compile(text);
}
protected synchronized XPathExpression createTraceNamespaceExpression() throws XPathFactoryConfigurationException, XPathExpressionException {
// XPathFactory is not thread safe
XPath xPath = getXPathFactory().newXPath();
return xPath.compile(OBTAIN_ALL_NS_XPATH);
}
protected DefaultNamespaceContext createNamespaceContext(XPathFactory factory) {
DefaultNamespaceContext context = new DefaultNamespaceContext(factory);
populateDefaultNamespaces(context);
return context;
}
/**
* Populate a number of standard prefixes if they are not already there
*/
protected void populateDefaultNamespaces(DefaultNamespaceContext context) {
setNamespaceIfNotPresent(context, "in", IN_NAMESPACE);
setNamespaceIfNotPresent(context, "out", OUT_NAMESPACE);
setNamespaceIfNotPresent(context, "env", Namespaces.ENVIRONMENT_VARIABLES);
setNamespaceIfNotPresent(context, "system", Namespaces.SYSTEM_PROPERTIES_NAMESPACE);
setNamespaceIfNotPresent(context, "function", Namespaces.FUNCTION_NAMESPACE);
}
protected void setNamespaceIfNotPresent(DefaultNamespaceContext context, String prefix, String uri) {
if (context != null) {
String current = context.getNamespaceURI(prefix);
if (current == null) {
context.add(prefix, uri);
}
}
}
protected XPathFunctionResolver createDefaultFunctionResolver(final XPathFunctionResolver parent) {
return new XPathFunctionResolver() {
public XPathFunction resolveFunction(QName qName, int argumentCount) {
XPathFunction answer = null;
if (parent != null) {
answer = parent.resolveFunction(qName, argumentCount);
}
if (answer == null) {
if (isMatchingNamespaceOrEmptyNamespace(qName.getNamespaceURI(), IN_NAMESPACE)
|| isMatchingNamespaceOrEmptyNamespace(qName.getNamespaceURI(), DEFAULT_NAMESPACE)) {
String localPart = qName.getLocalPart();
if (localPart.equals("body") && argumentCount == 0) {
return getBodyFunction();
}
if (localPart.equals("header") && argumentCount == 1) {
return getHeaderFunction();
}
}
if (isMatchingNamespaceOrEmptyNamespace(qName.getNamespaceURI(), OUT_NAMESPACE)) {
String localPart = qName.getLocalPart();
if (localPart.equals("body") && argumentCount == 0) {
return getOutBodyFunction();
}
if (localPart.equals("header") && argumentCount == 1) {
return getOutHeaderFunction();
}
}
if (isMatchingNamespaceOrEmptyNamespace(qName.getNamespaceURI(), FUNCTION_NAMESPACE)) {
String localPart = qName.getLocalPart();
if (localPart.equals("properties") && argumentCount == 1) {
return getPropertiesFunction();
}
if (localPart.equals("simple") && argumentCount == 1) {
return getSimpleFunction();
}
}
}
return answer;
}
};
}
/**
* Checks whether we need an {@link InputStream} to access the message body.
*
* Depending on the content in the message body, we may not need to convert
* to {@link InputStream}.
*
* @param exchange the current exchange
* @return true to convert to {@link InputStream} beforehand converting afterwards.
*/
protected boolean isInputStreamNeeded(Exchange exchange) {
Object body = exchange.getIn().getBody();
return isInputStreamNeededForObject(exchange, body);
}
/**
* Checks whether we need an {@link InputStream} to access the message header.
*
* Depending on the content in the message header, we may not need to convert
* to {@link InputStream}.
*
* @param exchange the current exchange
* @return true to convert to {@link InputStream} beforehand converting afterwards.
*/
protected boolean isInputStreamNeeded(Exchange exchange, String headerName) {
Object header = exchange.getIn().getHeader(headerName);
return isInputStreamNeededForObject(exchange, header);
}
/**
* Checks whether we need an {@link InputStream} to access this object
*
* Depending on the content in the object, we may not need to convert
* to {@link InputStream}.
*
* @param exchange the current exchange
* @return true to convert to {@link InputStream} beforehand converting afterwards.
*/
protected boolean isInputStreamNeededForObject(Exchange exchange, Object obj) {
if (obj == null) {
return false;
}
if (obj instanceof WrappedFile) {
obj = ((WrappedFile) obj).getFile();
}
if (obj instanceof File) {
// input stream is needed for File to avoid locking the file in case of errors etc
return true;
}
// input stream is not needed otherwise
return false;
}
/**
* Strategy method to extract the document from the exchange.
*/
protected Object getDocument(Exchange exchange, Object body) {
try {
return doGetDocument(exchange, body);
} catch (Exception e) {
throw ObjectHelper.wrapRuntimeCamelException(e);
} finally {
// call the reset if the in message body is StreamCache
MessageHelper.resetStreamCache(exchange.getIn());
}
}
protected Object doGetDocument(Exchange exchange, Object body) throws Exception {
if (body == null) {
return null;
}
Object answer = null;
Class type = getDocumentType();
Exception cause = null;
if (type != null) {
// try to get the body as the desired type
try {
answer = exchange.getContext().getTypeConverter().convertTo(type, exchange, body);
} catch (Exception e) {
// we want to store the caused exception, if we could not convert
cause = e;
}
}
if (type == null && answer == null) {
// fallback to get the body as is
answer = body;
} else if (answer == null) {
// there was a type, and we could not convert to it, then fail
if (cause != null) {
throw cause;
} else {
throw new NoTypeConversionAvailableException(body, type);
}
}
return answer;
}
private MessageVariableResolver getVariableResolver() {
return variableResolver;
}
@Override
public void doStart() throws Exception {
if (xpathFactory == null) {
xpathFactory = createXPathFactory();
}
if (namespaceContext == null) {
namespaceContext = createNamespaceContext(xpathFactory);
}
for (Map.Entry entry : namespaces.entrySet()) {
namespaceContext.add(entry.getKey(), entry.getValue());
}
// create default functions if no custom assigned
if (bodyFunction == null) {
bodyFunction = createBodyFunction();
}
if (headerFunction == null) {
headerFunction = createHeaderFunction();
}
if (outBodyFunction == null) {
outBodyFunction = createOutBodyFunction();
}
if (outHeaderFunction == null) {
outHeaderFunction = createOutHeaderFunction();
}
if (propertiesFunction == null) {
propertiesFunction = createPropertiesFunction();
}
if (simpleFunction == null) {
simpleFunction = createSimpleFunction();
}
}
@Override
public void doStop() throws Exception {
pool.clear();
poolLogNamespaces.clear();
}
protected synchronized XPathFactory createXPathFactory() throws XPathFactoryConfigurationException {
if (objectModelUri != null) {
String xpathFactoryClassName = factoryClassName;
if (objectModelUri.equals(SAXON_OBJECT_MODEL_URI) && (xpathFactoryClassName == null || SAXON_FACTORY_CLASS_NAME.equals(xpathFactoryClassName))) {
// from Saxon 9.7 onwards you should favour to create the class directly
// https://www.saxonica.com/html/documentation/xpath-api/jaxp-xpath/factory.html
try {
if (camelContext != null) {
Class clazz = camelContext.getClassResolver().resolveClass(SAXON_FACTORY_CLASS_NAME, XPathFactory.class);
if (clazz != null) {
LOG.debug("Creating Saxon XPathFactory using class: {})", clazz);
xpathFactory = camelContext.getInjector().newInstance(clazz);
LOG.info("Created Saxon XPathFactory: {}", xpathFactory);
}
}
} catch (Throwable e) {
LOG.warn("Attempted to create Saxon XPathFactory by creating a new instance of " + SAXON_FACTORY_CLASS_NAME
+ " failed. Will fallback and create XPathFactory using JDK API. This exception is ignored (stacktrace in DEBUG logging level).");
LOG.debug("Error creating Saxon XPathFactory. This exception is ignored.", e);
}
}
if (xpathFactory == null) {
LOG.debug("Creating XPathFactory from objectModelUri: {}", objectModelUri);
xpathFactory = ObjectHelper.isEmpty(xpathFactoryClassName)
? XPathFactory.newInstance(objectModelUri)
: XPathFactory.newInstance(objectModelUri, xpathFactoryClassName, null);
LOG.info("Created XPathFactory: {} from objectModelUri: {}", xpathFactory, objectModelUri);
}
return xpathFactory;
}
if (defaultXPathFactory == null) {
defaultXPathFactory = createDefaultXPathFactory();
}
return defaultXPathFactory;
}
protected static XPathFactory createDefaultXPathFactory() throws XPathFactoryConfigurationException {
XPathFactory factory = null;
// read system property and see if there is a factory set
Properties properties = System.getProperties();
for (Map.Entry prop : properties.entrySet()) {
String key = (String) prop.getKey();
if (key.startsWith(XPathFactory.DEFAULT_PROPERTY_NAME)) {
String uri = ObjectHelper.after(key, ":");
if (uri != null) {
factory = XPathFactory.newInstance(uri);
LOG.info("Using system property {} with value {} when created default XPathFactory {}", new Object[]{key, uri, factory});
}
}
}
if (factory == null) {
factory = XPathFactory.newInstance();
LOG.info("Created default XPathFactory {}", factory);
}
return factory;
}
}