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Checkstyle is a development tool to help programmers write Java code
that adheres to a coding standard
////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2016 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Set;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import com.google.common.collect.Sets;
import com.google.common.io.Closeables;
import com.puppycrawl.tools.checkstyle.api.AbstractLoader;
import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
/**
* Loads a list of package names from a package name XML file.
* @author Rick Giles
*/
public final class PackageNamesLoader
extends AbstractLoader {
/** The public ID for the configuration dtd. */
private static final String DTD_PUBLIC_ID =
"-//Puppy Crawl//DTD Package Names 1.0//EN";
/** The resource for the configuration dtd. */
private static final String DTD_RESOURCE_NAME =
"com/puppycrawl/tools/checkstyle/packages_1_0.dtd";
/** Name of default checkstyle package names resource file.
* The file must be in the classpath.
*/
private static final String CHECKSTYLE_PACKAGES =
"checkstyle_packages.xml";
/** Qualified name for element 'package'. */
private static final String PACKAGE_ELEMENT_NAME = "package";
/** The temporary stack of package name parts. */
private final Deque packageStack = new ArrayDeque<>();
/** The fully qualified package names. */
private final Set packageNames = Sets.newLinkedHashSet();
/**
* Creates a new {@code PackageNamesLoader} instance.
* @throws ParserConfigurationException if an error occurs
* @throws SAXException if an error occurs
*/
private PackageNamesLoader()
throws ParserConfigurationException, SAXException {
super(DTD_PUBLIC_ID, DTD_RESOURCE_NAME);
}
@Override
public void startElement(String uri,
String localName,
String qName,
Attributes attributes) {
if (PACKAGE_ELEMENT_NAME.equals(qName)) {
//push package name, name is mandatory attribute with not empty value by DTD
final String name = attributes.getValue("name");
packageStack.push(name);
}
}
/**
* Creates a full package name from the package names on the stack.
* @return the full name of the current package.
*/
private String getPackageName() {
final StringBuilder buf = new StringBuilder();
final Iterator iterator = packageStack.descendingIterator();
while (iterator.hasNext()) {
final String subPackage = iterator.next();
buf.append(subPackage);
if (!CommonUtils.endsWithChar(subPackage, '.')) {
buf.append('.');
}
}
return buf.toString();
}
@Override
public void endElement(String uri,
String localName,
String qName) {
if (PACKAGE_ELEMENT_NAME.equals(qName)) {
packageNames.add(getPackageName());
packageStack.pop();
}
}
/**
* Returns the set of package names, compiled from all
* checkstyle_packages.xml files found on the given class loaders
* classpath.
* @param classLoader the class loader for loading the
* checkstyle_packages.xml files.
* @return the set of package names.
* @throws CheckstyleException if an error occurs.
*/
public static Set getPackageNames(ClassLoader classLoader)
throws CheckstyleException {
final Set result;
try {
//create the loader outside the loop to prevent PackageObjectFactory
//being created anew for each file
final PackageNamesLoader namesLoader = new PackageNamesLoader();
final Enumeration packageFiles = classLoader.getResources(CHECKSTYLE_PACKAGES);
while (packageFiles.hasMoreElements()) {
final URL packageFile = packageFiles.nextElement();
InputStream stream = null;
try {
stream = new BufferedInputStream(packageFile.openStream());
final InputSource source = new InputSource(stream);
namesLoader.parseInputSource(source);
}
catch (IOException ex) {
throw new CheckstyleException("unable to open " + packageFile, ex);
}
finally {
Closeables.closeQuietly(stream);
}
}
result = namesLoader.packageNames;
}
catch (IOException ex) {
throw new CheckstyleException("unable to get package file resources", ex);
}
catch (ParserConfigurationException | SAXException ex) {
throw new CheckstyleException("unable to open one of package files", ex);
}
return result;
}
}