org.apache.wicket.util.file.WebXmlFile Maven / Gradle / Ivy
/*
* 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.wicket.util.file;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.wicket.util.xml.CustomEntityResolver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
/**
* A utility class providing helper methods in dealing with web.xml
*
* @author jcompagner
* @author Juergen Donnerstag
*/
public class WebXmlFile
{
private static final Logger log = LoggerFactory.getLogger(WebXmlFile.class);
/**
* Construct.
*/
public WebXmlFile()
{
}
/**
* Gets unique Wicket filter path via FilterConfig
*
* @param isServlet
* true if Servlet, false if Filter
* @param filterConfig
* @return Filter path retrieved from "url-pattern". Null if not found or error occurred
*/
public final String getUniqueFilterPath(final boolean isServlet, final FilterConfig filterConfig)
{
String filterName = filterConfig.getFilterName();
Set paths = getFilterPath(isServlet, filterConfig.getServletContext(), filterName);
return uniquePath(paths, isServlet, filterName);
}
/**
* Gets Wicket filter path via ServletContext and the filter name
*
* @param isServlet
* true if Servlet, false if Filter
* @param servletContext
* @param filterName
* @return Filter paths retrieved from "url-pattern"
*/
public final Set getFilterPath(final boolean isServlet,
final ServletContext servletContext, final String filterName)
{
InputStream is = servletContext.getResourceAsStream("/WEB-INF/web.xml");
if (is != null)
{
try
{
return getFilterPath(isServlet, filterName, is);
}
catch (ParserConfigurationException | SAXException | IOException ex)
{
log.error("Error reading servlet/filter path from web.xml", ex);
}
catch (SecurityException e)
{
// Swallow this at INFO.
log.info("Couldn't read web.xml to automatically pick up servlet/filter path: " +
e.getMessage());
}
}
return Collections.emptySet();
}
/**
* Gets unique filter path via filter name and InputStream.
*
* @param isServlet
* true if Servlet, false if Filter
* @param filterName
* @param is
* The web.xml file
* @return Filter path retrieved from "url-pattern". Null if not found.
* @throws ParserConfigurationException
* @throws IOException
* @throws SAXException
*
* @see #getFilterPath(boolean, String, java.io.InputStream)
*/
public final String getUniqueFilterPath(final boolean isServlet, final String filterName,
final InputStream is) throws ParserConfigurationException, SAXException, IOException
{
return uniquePath(getFilterPath(isServlet, filterName, is), isServlet, filterName);
}
/**
* return unique path from set of paths
*
* @param paths
* null if set was empty, unique path if set was of length == 1
* @param isServlet
* @param filterName
* @return unique path
* @throws RuntimeException
* in case length > 1
*/
private String uniquePath(final Set paths, final boolean isServlet,
final String filterName)
{
if (paths.size() > 1)
{
StringBuilder err = new StringBuilder();
err.append("web.xml: expected one ");
err.append(isServlet ? "servlet" : "filter");
err.append(" path for [");
err.append(filterName);
err.append("] but found multiple:");
for (String path : paths)
{
err.append(" [").append(path).append(']');
}
throw new RuntimeException(err.toString());
}
if (paths.size() == 1)
{
return paths.iterator().next();
}
return null;
}
/**
* Gets Wicket filter path via filter name and InputStream. The InputStream is assumed to be an
* web.xml file.
*
* A typical Wicket web.xml entry looks like:
*
*
*
* <filter>
* <filter-name>HelloWorldApplication</filter-name>
* <filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>
* <init-param>
* <param-name>applicationClassName</param-name>
* <param-value>org.apache.wicket.examples.helloworld.HelloWorldApplication</param-value>
* </init-param>
* </filter>
*
* <filter-mapping>
* <filter-name>HelloWorldApplication</filter-name>
* <url-pattern>/helloworld/*</url-pattern>
* <dispatcher>REQUEST</dispatcher>
* <dispatcher>INCLUDE</dispatcher>
* </filter-mapping>
*
*
*
* @param isServlet
* true if Servlet, false if Filter
* @param filterName
* @param is
* The web.xml file
* @return Filter paths retrieved from "url-pattern".
* @throws ParserConfigurationException
* @throws IOException
* @throws SAXException
*/
public final Set getFilterPath(final boolean isServlet, final String filterName,
final InputStream is) throws ParserConfigurationException, SAXException, IOException
{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
// try to pull DTD from local set of entities
builder.setEntityResolver(CustomEntityResolver.getPreloaded());
Document document = builder.parse(is);
String tag = (isServlet ? "servlet" : "filter");
String mapping = tag + "-mapping";
String name = tag + "-name";
Set urlPatterns = getFilterPaths(filterName, mapping, name,
document.getChildNodes());
if (urlPatterns.size() == 0)
{
log.warn("web.xml: No url-pattern found for '{}' with name '{}'", tag, filterName);
}
if (log.isInfoEnabled())
{
StringBuilder msg = new StringBuilder();
msg.append("web.xml: url mapping found for ")
.append(tag)
.append(" with name ")
.append(filterName)
.append(':');
for (String urlPattern : urlPatterns)
{
msg.append(" [");
msg.append(urlPattern);
msg.append(']');
}
log.info(msg.toString());
}
Set stripped = new HashSet<>(urlPatterns.size());
for (String urlPattern : urlPatterns)
{
stripped.add(urlPattern.substring(1, urlPattern.length() - 1));
}
return stripped;
}
/**
* Iterate through all children of 'node' and search for a node with name "filterName". Return
* the value of node "url-pattern" if "filterName" was found.
*
* @param filterName
* @param name
* @param node
* @return value of node "url-pattern"
*/
private Set getFilterPaths(final String filterName, final String name, final Node node)
{
Set paths = new HashSet<>();
String foundUrlPattern = null;
String foundFilterName = null;
for (int i = 0; i < node.getChildNodes().getLength(); ++i)
{
Node n = node.getChildNodes().item(i);
if (name.equals(n.getNodeName()))
{
foundFilterName = n.getTextContent();
}
else if ("url-pattern".equals(n.getNodeName()))
{
foundUrlPattern = n.getTextContent();
}
if (foundFilterName != null)
{
foundFilterName = foundFilterName.trim();
}
if (filterName.equals(foundFilterName))
{
if (foundUrlPattern != null)
{
paths.add(foundUrlPattern.trim());
}
}
}
return paths;
}
/**
* Find a node with name 'mapping' within 'nodeList' and if found continue to search amongst its
* children for a node with 'filterName' and "url-pattern'
*
*
* @param filterName
* @param mapping
* @param name
* @param nodeList
* @return The value assigned to node "url-pattern"
*/
private Set getFilterPaths(final String filterName, final String mapping,
final String name, final NodeList nodeList)
{
Set paths = new HashSet<>(1);
for (int i = 0; i < nodeList.getLength(); ++i)
{
Node node = nodeList.item(i);
if (mapping.equals(node.getNodeName()))
{
paths.addAll(getFilterPaths(filterName, name, node));
}
else
{
paths.addAll(getFilterPaths(filterName, mapping, name, node.getChildNodes()));
}
}
return paths;
}
}