/*
* Copyright 2006 The Apache Software Foundation.
* Copyright 2006 International Business Machines Corp.
*
* 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.apache.axis2.jaxws.message.attachments;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNode;
import org.apache.axiom.om.OMText;
import org.apache.axiom.om.impl.llom.OMNavigator;
import org.apache.axiom.soap.SOAPEnvelope;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import javax.activation.DataHandler;
import javax.xml.namespace.QName;
import java.util.ArrayList;
/** A suite of utilities used for handling MTOM attachment data. */
public class AttachmentUtils {
private static final Log log = LogFactory.getLog(AttachmentUtils.class);
private static final QName XOP_INCLUDE =
new QName("http://www.w3.org/2004/08/xop/include", "Include");
/**
* Can be used to find all instances of the <pre><xop:include></pre> element
* within a given OM SOAPEnvelope.
*
* @param env
* @return
*/
public static ArrayList<OMElement> findXopElements(OMElement env) {
ArrayList<OMElement> xops = new ArrayList<OMElement>();
findXopElements(env, xops);
return xops;
}
/*
* A recursive search for all of the <xop:include> elements in the tree.
*/
private static void findXopElements(OMElement root, ArrayList<OMElement> xops) {
// Forces a parse. This seems to be necessary due to bugs in OMNavigator
root.getNextOMSibling();
// Navigator does a traversal that mimics the structure of an xml document.
// Each non-element object is processed once.
// Each element object is visited prior to its children and after its children.
//
// Suppose you have the following tree (caps are elements, lowers are text)
//
// A
// / \
// B C
// /\ /\
// D e F g
//
// The traversal is
// is A B D D' e B' C F F' g C' A'
// The ' indicates that this is the second time the node is visited (i.e. nav.visited() returns true)
OMNavigator nav = new OMNavigator(root);
while (nav.isNavigable()) {
OMNode curr = nav.next();
// Inspect elements that have been visited.
// It is probably safer to inspect the node when it is visited, because this guarantees that its
// children have been processed/expanded.
if (nav.visited() && curr instanceof OMElement) {
OMElement element = (OMElement)curr;
if (element.getQName().equals(XOP_INCLUDE)) {
if (log.isDebugEnabled()) {
log.debug("[XOP_INCLUDE] " + element.getLocalName());
}
xops.add(element);
}
}
}
/* LEGACY SEARCH CODE
// If it has no children, then it's a leaf and we need
// to check if it's an <xop:include> element. If not, then
// we need to grab each of the children and continue traversing
// down the tree.
Iterator itr = root.getChildren();
if (itr == null || !itr.hasNext()) {
if (log.isDebugEnabled())
log.debug("[leaf] " + root.getLocalName());
if (root.getQName().equals(XOP_INCLUDE)) {
xops.add(root);
}
}
else if (itr != null && itr.hasNext()) {
while (itr.hasNext()) {
OMElement next = (OMElement) itr.next();
findXopElements(next, xops);
}
}
*/
}
/**
* Can be used to find all of the nodes in a tree that contain binary content that is targetted
* for optimization via MTOM.
*
* @param env
* @return
*/
public static ArrayList<OMText> findBinaryNodes(SOAPEnvelope env) {
ArrayList<OMText> nodes = new ArrayList<OMText>();
findBinaryElements(env, nodes);
return nodes;
}
/*
* A recursive search for all of the binary, optimized nodes in a tree.
*/
private static void findBinaryElements(OMNode node, ArrayList<OMText> attachments) {
// Forces a parse. This seems to be necessary due to bugs in OMNavigator
node.getNextOMSibling();
// Navigator does a traversal that mimics the structure of an xml document.
// Each non-element object is processed once.
// Each element object is visited prior to its children and after its children.
//
// Suppose you have the following tree (caps are elements, lowers are text)
//
// A
// / \
// B C
// /\ /\
// D e F g
//
// The traversal is
// The traversal is
// is A B D D' e B' C F F' g C' A'
// The ' indicates that this is the second time the node is visited (i.e. nav.isVisited() returns true)
OMNavigator nav = new OMNavigator(node);
while (nav.isNavigable()) {
OMNode curr = nav.next();
if (curr instanceof OMText) {
// If it's an OMText, see if its optimized and add it to the list
if (log.isDebugEnabled())
log.debug("text node found");
OMText textNode = (OMText)curr;
if (textNode.isOptimized()) {
if (log.isDebugEnabled())
log.debug("optimized text node found");
attachments.add(textNode);
}
}
}
/* LEGACY SEARCH CODE
if (node instanceof OMText) {
if (log.isDebugEnabled())
log.debug("text node found");
OMText textNode = (OMText) node;
if (textNode.isOptimized()) {
if (log.isDebugEnabled())
log.debug("optimized text node found");
attachments.add(textNode);
}
}
else if (node instanceof OMElement){
OMElement element = (OMElement) node;
Iterator itr = element.getChildren();
while (itr.hasNext()) {
OMNode next = (OMNode) itr.next();
findBinaryElements(next, attachments);
}
}
*/
}
/**
* Given an <pre><xop:include></pre> element, create an OMText element
* with the appropriate attachment data.
*
* @param xop
* @param data
* @return
*/
public static OMText makeBinaryOMNode(OMElement xop, DataHandler dh) {
OMFactory factory = xop.getOMFactory();
OMText binaryNode = factory.createOMText(dh, true);
return binaryNode;
}
/**
* Given an OMText node, create it's corresponding <pre><xop:include></pre>
* element.
*/
public static OMElement makeXopElement(OMText data) {
OMFactory factory = data.getOMFactory();
OMElement xop = factory.createOMElement(XOP_INCLUDE, null);
xop.addAttribute("href", data.getContentID(), null);
return xop;
}
}