/*
* Copyright 2005-2014 the original author or authors.
*
* Licensed 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.springframework.ws.server.endpoint.adapter.method;
import javax.xml.namespace.QName;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.dom.DOMResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.springframework.core.MethodParameter;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.support.ConversionServiceFactory;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.ws.context.MessageContext;
import org.springframework.ws.server.endpoint.annotation.XPathParam;
import org.springframework.ws.server.endpoint.support.NamespaceUtils;
import org.springframework.xml.transform.TransformerHelper;
/**
* Implementation of {@link MethodArgumentResolver} that supports the {@link XPathParam @XPathParam} annotation.
*
* <p>This resolver supports parameters annotated with {@link XPathParam @XPathParam} that specifies the XPath expression
* that should be bound to that parameter. The parameter can either a "natively supported" XPath type ({@link Boolean
* boolean}, {@link Double double}, {@link String}, {@link Node}, or {@link NodeList}), or a type that is {@linkplain
* ConversionService#canConvert(Class, Class) supported} by the {@link ConversionService}.
*
* @author Arjen Poutsma
* @since 2.0
*/
public class XPathParamMethodArgumentResolver implements MethodArgumentResolver {
private final XPathFactory xpathFactory = createXPathFactory();
private TransformerHelper transformerHelper = new TransformerHelper();
private ConversionService conversionService = new DefaultConversionService();
/**
* Sets the conversion service to use.
*
* <p>Defaults to the {@linkplain ConversionServiceFactory#createDefaultConversionService() default conversion
* service}.
*/
public void setConversionService(ConversionService conversionService) {
this.conversionService = conversionService;
}
public void setTransformerHelper(TransformerHelper transformerHelper) {
this.transformerHelper = transformerHelper;
}
@Override
public boolean supportsParameter(MethodParameter parameter) {
if (parameter.getParameterAnnotation(XPathParam.class) == null) {
return false;
}
Class<?> parameterType = parameter.getParameterType();
if (Boolean.class.equals(parameterType) || Boolean.TYPE.equals(parameterType) ||
Double.class.equals(parameterType) || Double.TYPE.equals(parameterType) ||
Node.class.isAssignableFrom(parameterType) || NodeList.class.isAssignableFrom(parameterType) ||
String.class.isAssignableFrom(parameterType)) {
return true;
}
else {
return conversionService.canConvert(String.class, parameterType);
}
}
@Override
public Object resolveArgument(MessageContext messageContext, MethodParameter parameter)
throws TransformerException, XPathExpressionException {
Class<?> parameterType = parameter.getParameterType();
QName evaluationReturnType = getReturnType(parameterType);
boolean useConversionService = false;
if (evaluationReturnType == null) {
evaluationReturnType = XPathConstants.STRING;
useConversionService = true;
}
XPath xpath = createXPath();
xpath.setNamespaceContext(NamespaceUtils.getNamespaceContext(parameter.getMethod()));
Element rootElement = getRootElement(messageContext.getRequest().getPayloadSource());
String expression = parameter.getParameterAnnotation(XPathParam.class).value();
Object result = xpath.evaluate(expression, rootElement, evaluationReturnType);
return useConversionService ? conversionService.convert(result, parameterType) : result;
}
private QName getReturnType(Class<?> parameterType) {
if (Boolean.class.equals(parameterType) || Boolean.TYPE.equals(parameterType)) {
return XPathConstants.BOOLEAN;
}
else if (Double.class.equals(parameterType) || Double.TYPE.equals(parameterType)) {
return XPathConstants.NUMBER;
}
else if (Node.class.equals(parameterType)) {
return XPathConstants.NODE;
}
else if (NodeList.class.equals(parameterType)) {
return XPathConstants.NODESET;
}
else if (String.class.equals(parameterType)) {
return XPathConstants.STRING;
}
else {
return null;
}
}
private XPath createXPath() {
synchronized (xpathFactory) {
return xpathFactory.newXPath();
}
}
private Element getRootElement(Source source) throws TransformerException {
DOMResult domResult = new DOMResult();
transformerHelper.transform(source, domResult);
Document document = (Document) domResult.getNode();
return document.getDocumentElement();
}
/**
* Create a {@code XPathFactory} that this resolver will use to create {@link XPath} objects.
*
* <p>Can be overridden in subclasses, adding further initialization of the factory. The resulting factory is cached,
* so this method will only be called once.
*
* @return the created factory
*/
protected XPathFactory createXPathFactory() {
return XPathFactory.newInstance();
}
}