freemarker.ext.dom.SunInternalXalanXPathSupport Maven / Gradle / Ivy
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Google App Engine compliant variation of FreeMarker.
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* 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 freemarker.ext.dom;
import java.util.List;
import javax.xml.transform.TransformerException;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeIterator;
import com.sun.org.apache.xml.internal.utils.PrefixResolver;
import com.sun.org.apache.xpath.internal.XPath;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.objects.XBoolean;
import com.sun.org.apache.xpath.internal.objects.XNodeSet;
import com.sun.org.apache.xpath.internal.objects.XNull;
import com.sun.org.apache.xpath.internal.objects.XNumber;
import com.sun.org.apache.xpath.internal.objects.XObject;
import com.sun.org.apache.xpath.internal.objects.XString;
import freemarker.core.Environment;
import freemarker.template.SimpleNumber;
import freemarker.template.SimpleScalar;
import freemarker.template.Template;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
/**
* XPath support implemented on the internal Xalan that is packed into Java under {@code com.sun} packages. This
* won't be accessible if Java 9 module access rules are enforced (like if the application is started with
* {@code java --illegal-access=deny}), because then accessing {@code com.sun} packages is banned. In such case
* {@link XalanXPathSupport} can be used, which however needs the normal Apache Xalan to be present.
*/
class SunInternalXalanXPathSupport implements XPathSupport {
private XPathContext xpathContext = new XPathContext();
@Override
synchronized public TemplateModel executeQuery(Object context, String xpathQuery) throws TemplateModelException {
if (!(context instanceof Node)) {
if (context == null || isNodeList(context)) {
int cnt = context != null ? ((List) context).size() : 0;
throw new TemplateModelException(
(cnt != 0
? "Xalan can't perform an XPath query against a Node Set (contains " + cnt
+ " node(s)). Expecting a single Node."
: "Xalan can't perform an XPath query against an empty Node Set."
)
+ " (There's no such restriction if you configure FreeMarker to use Jaxen for XPath.)");
} else {
throw new TemplateModelException(
"Can't perform an XPath query against a " + context.getClass().getName()
+ ". Expecting a single org.w3c.dom.Node.");
}
}
Node node = (Node) context;
try {
XPath xpath = new XPath(xpathQuery, null, CUSTOM_PREFIX_RESOLVER, XPath.SELECT, null);
int ctxtNode = xpathContext.getDTMHandleFromNode(node);
XObject xresult = xpath.execute(xpathContext, ctxtNode, CUSTOM_PREFIX_RESOLVER);
if (xresult instanceof XNodeSet) {
NodeListModel result = new NodeListModel(node);
result.xpathSupport = this;
NodeIterator nodeIterator = xresult.nodeset();
Node n;
do {
n = nodeIterator.nextNode();
if (n != null) {
result.add(n);
}
} while (n != null);
return result.size() == 1 ? result.get(0) : result;
}
if (xresult instanceof XBoolean) {
return ((XBoolean) xresult).bool() ? TemplateBooleanModel.TRUE : TemplateBooleanModel.FALSE;
}
if (xresult instanceof XNull) {
return null;
}
if (xresult instanceof XString) {
return new SimpleScalar(xresult.toString());
}
if (xresult instanceof XNumber) {
return new SimpleNumber(Double.valueOf(((XNumber) xresult).num()));
}
throw new TemplateModelException("Cannot deal with type: " + xresult.getClass().getName());
} catch (TransformerException te) {
throw new TemplateModelException(te);
}
}
private static final PrefixResolver CUSTOM_PREFIX_RESOLVER = new PrefixResolver() {
@Override
public String getNamespaceForPrefix(String prefix, Node node) {
return getNamespaceForPrefix(prefix);
}
@Override
public String getNamespaceForPrefix(String prefix) {
if (prefix.equals(Template.DEFAULT_NAMESPACE_PREFIX)) {
return Environment.getCurrentEnvironment().getDefaultNS();
}
return Environment.getCurrentEnvironment().getNamespaceForPrefix(prefix);
}
@Override
public String getBaseIdentifier() {
return null;
}
@Override
public boolean handlesNullPrefixes() {
return false;
}
};
/**
* Used for generating more intelligent error messages.
*/
private static boolean isNodeList(Object context) {
if (!(context instanceof List)) {
return false;
}
List ls = (List) context;
int ln = ls.size();
for (int i = 0; i < ln; i++) {
if (!(ls.get(i) instanceof Node)) {
return false;
}
}
return true;
}
}