/*
* Copyright 2009 Google Inc.
*
* 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 com.google.gwt.dev;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.dev.util.collect.HashSet;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.Stack;
import java.util.Map.Entry;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
/**
* Validates that <code><servlet></code> tags in a GWT module match ones
* from a <code>WEB-INF/web.xml</code>.
*/
class ServletValidator {
/**
* Collect servlet information from a web xml.
*/
private static final class WebXmlDataCollector extends DefaultHandler {
/*
* TODO(scottb): this should have been implemented as a Schema.
*/
private static class ElementStack {
private final Stack<String> stack = new Stack<String>();
public boolean exactly(String elementName, int depth) {
return (depth == stack.size() - 1)
&& elementName.equals(stack.get(depth));
}
public String peek() {
return stack.peek();
}
public String pop() {
return stack.pop();
}
public void push(String elementName) {
stack.push(elementName);
}
public boolean within(String elementName, int depth) {
return (depth < stack.size()) && elementName.equals(stack.get(depth));
}
}
private Set<String> accumulateClasses = new HashSet<String>();
private Set<String> accumulatePaths = new HashSet<String>();
private final TreeLogger branch;
private final Stack<StringBuilder> cdataStack = new Stack<StringBuilder>();
private final Map<String, String> classNameToServletName;
private final ElementStack context = new ElementStack();
private String currentServletName;
private String indent = "";
private final Map<String, Set<String>> servletNameToPaths;
private WebXmlDataCollector(TreeLogger branch,
Map<String, String> classNameToServletName,
Map<String, Set<String>> servletNameToPaths) {
this.branch = branch;
this.classNameToServletName = classNameToServletName;
this.servletNameToPaths = servletNameToPaths;
}
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
cdataStack.peek().append(ch, start, length);
}
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
String cdata = cdataStack.pop().toString().trim();
if (context.within("web-app", 0)) {
if (context.within("servlet", 1)) {
if (context.exactly("servlet-name", 2)) {
currentServletName = cdata;
} else if (context.exactly("servlet-class", 2)) {
accumulateClasses.add(cdata);
} else if (context.exactly("servlet", 1)) {
if (currentServletName != null) {
for (String className : accumulateClasses) {
classNameToServletName.put(className, currentServletName);
}
currentServletName = null;
}
accumulateClasses.clear();
}
} else if (context.within("servlet-mapping", 1)) {
if (context.exactly("servlet-name", 2)) {
currentServletName = cdata;
} else if (context.exactly("url-pattern", 2)) {
accumulatePaths.add(cdata);
} else if (context.exactly("servlet-mapping", 1)) {
if (currentServletName != null) {
Set<String> servletPaths = servletNameToPaths.get(currentServletName);
if (servletPaths == null) {
servletPaths = new HashSet<String>();
servletNameToPaths.put(currentServletName, servletPaths);
}
servletPaths.addAll(accumulatePaths);
}
currentServletName = null;
accumulatePaths.clear();
}
}
}
assert qName.equals(context.peek());
context.pop();
if (cdata.length() > 0) {
if (branch.isLoggable(TreeLogger.DEBUG)) {
branch.log(TreeLogger.DEBUG, " characters: " + indent + cdata);
}
}
indent = indent.substring(2);
if (branch.isLoggable(TreeLogger.DEBUG)) {
branch.log(TreeLogger.DEBUG, " endElement: " + indent + qName);
}
}
@Override
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
context.push(qName);
cdataStack.push(new StringBuilder());
StringBuilder sb = new StringBuilder();
for (int i = 0; i < attributes.getLength(); ++i) {
sb.append(' ');
sb.append(attributes.getQName(i));
sb.append("=\"");
sb.append(attributes.getValue(i));
sb.append('"');
}
if (branch.isLoggable(TreeLogger.DEBUG)) {
branch.log(TreeLogger.DEBUG, "startElement: " + indent + qName
+ sb.toString());
}
indent += " ";
}
}
public static ServletValidator create(TreeLogger logger, File webXml) {
try {
return create(logger, webXml.toURI().toURL());
} catch (MalformedURLException e) {
logger.log(TreeLogger.WARN, "Unable to process '"
+ webXml.getAbsolutePath() + "' for servlet validation", e);
return null;
}
}
public static ServletValidator create(TreeLogger logger, URL webXmlUrl) {
String webXmlUrlString = webXmlUrl.toExternalForm();
try {
final TreeLogger branch = logger.branch(TreeLogger.DEBUG, "Parsing "
+ webXmlUrlString);
SAXParserFactory fac = SAXParserFactory.newInstance();
fac.setValidating(false);
fac.setNamespaceAware(false);
fac.setFeature(
"http://apache.org/xml/features/nonvalidating/load-external-dtd",
false);
SAXParser parser = fac.newSAXParser();
parser.getXMLReader().setFeature(
"http://xml.org/sax/features/validation", false);
parser.getXMLReader().setFeature(
"http://xml.org/sax/features/namespaces", false);
parser.getXMLReader().setFeature(
"http://xml.org/sax/features/namespace-prefixes", false);
Map<String, String> classNameToServletName = new HashMap<String, String>();
Map<String, Set<String>> servletNameToPaths = new HashMap<String, Set<String>>();
parser.parse(webXmlUrlString, new WebXmlDataCollector(branch,
classNameToServletName, servletNameToPaths));
Map<String, Set<String>> classNameToPaths = new HashMap<String, Set<String>>();
for (Entry<String, String> entry : classNameToServletName.entrySet()) {
classNameToPaths.put(entry.getKey(),
servletNameToPaths.get(entry.getValue()));
}
return new ServletValidator(classNameToServletName, classNameToPaths);
} catch (Exception e) {
logger.log(TreeLogger.WARN, "Unable to process '" + webXmlUrlString
+ "' for servlet validation", e);
return null;
}
}
static String generateMissingMappingMessage(String servletClass,
String servletPath, String servletName) {
return "Module declares a servlet class '"
+ servletClass
+ "' with a mapping to '"
+ servletPath
+ "', but the web.xml has no corresponding mapping; please add the following lines to your web.xml:\n"
+ ServletWriter.generateServletMappingTag(servletName, servletPath);
}
static String generateMissingServletMessage(String servletClass,
String servletPath) {
String servletName = suggestServletName(servletClass);
return "Module declares a servlet class '"
+ servletClass
+ "', but the web.xml has no corresponding declaration; please add the following lines to your web.xml:\n"
+ ServletWriter.generateServletTag(servletName, servletClass) + "\n"
+ ServletWriter.generateServletMappingTag(servletName, servletPath);
}
static String suggestServletName(String servletClass) {
int pos = servletClass.lastIndexOf('.');
String suggest = (pos < 0) ? servletClass : servletClass.substring(pos + 1);
String firstChar = suggest.substring(0, 1).toLowerCase(Locale.ENGLISH);
suggest = firstChar + suggest.substring(1);
return suggest;
}
private final Map<String, Set<String>> classNameToPaths;
private final Map<String, String> classNameToServletName;
private ServletValidator(Map<String, String> classNameToServletName,
Map<String, Set<String>> classNameToPaths) {
this.classNameToServletName = classNameToServletName;
this.classNameToPaths = classNameToPaths;
}
public void validate(TreeLogger logger, String servletClass,
String servletPath) {
if (containsServletClass(servletClass)) {
if (!containsServletMapping(servletClass, servletPath)) {
String servletName = getNameForClass(servletClass);
assert (servletName != null);
logger.log(TreeLogger.WARN, generateMissingMappingMessage(servletClass,
servletPath, servletName));
}
} else {
logger.log(TreeLogger.WARN, generateMissingServletMessage(servletClass,
servletPath));
}
}
boolean containsServletClass(String servletClass) {
return classNameToServletName.get(servletClass) != null;
}
boolean containsServletMapping(String servletClass, String servletPath) {
Set<String> paths = classNameToPaths.get(servletClass);
return (paths != null) && paths.contains(servletPath);
}
String getNameForClass(String servletClass) {
return classNameToServletName.get(servletClass);
}
}