com.puppycrawl.tools.checkstyle.utils.ModuleReflectionUtil Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of checkstyle Show documentation
Show all versions of checkstyle Show documentation
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) 2001-2020 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.utils;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.Set;
import java.util.stream.Collectors;
import com.google.common.reflect.ClassPath;
import com.puppycrawl.tools.checkstyle.TreeWalkerFilter;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
import com.puppycrawl.tools.checkstyle.api.AuditListener;
import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
import com.puppycrawl.tools.checkstyle.api.BeforeExecutionFileFilter;
import com.puppycrawl.tools.checkstyle.api.Filter;
import com.puppycrawl.tools.checkstyle.api.RootModule;
/**
* Contains utility methods for module reflection.
*/
public final class ModuleReflectionUtil {
/** Prevent instantiation. */
private ModuleReflectionUtil() {
}
/**
* Gets checkstyle's modules (directly, not recursively) in the given packages.
* @param packages the collection of package names to use
* @param loader the class loader used to load Checkstyle package names
* @return the set of checkstyle's module classes
* @throws IOException if the attempt to read class path resources failed
* @see #isCheckstyleModule(Class)
*/
public static Set> getCheckstyleModules(
Collection packages, ClassLoader loader) throws IOException {
final ClassPath classPath = ClassPath.from(loader);
return packages.stream()
.flatMap(pkg -> classPath.getTopLevelClasses(pkg).stream())
.map(ClassPath.ClassInfo::load)
.filter(ModuleReflectionUtil::isCheckstyleModule)
.collect(Collectors.toSet());
}
/**
* Checks whether a class may be considered as a checkstyle module. Checkstyle's modules are
* non-abstract classes, which are either checkstyle's checks, file sets, filters, file filters,
* {@code TreeWalker} filters, audit listener, or root module.
* @param clazz class to check.
* @return true if the class may be considered as the checkstyle module.
*/
public static boolean isCheckstyleModule(Class clazz) {
return isValidCheckstyleClass(clazz)
&& (isCheckstyleTreeWalkerCheck(clazz)
|| isFileSetModule(clazz)
|| isFilterModule(clazz)
|| isFileFilterModule(clazz)
|| isTreeWalkerFilterModule(clazz)
|| isAuditListener(clazz)
|| isRootModule(clazz));
}
/**
* Checks whether a class extends 'AutomaticBean', is non-abstract, and has a default
* constructor.
* @param clazz class to check.
* @return true if a class may be considered a valid production class.
*/
public static boolean isValidCheckstyleClass(Class clazz) {
return AutomaticBean.class.isAssignableFrom(clazz)
&& !Modifier.isAbstract(clazz.getModifiers())
&& hasDefaultConstructor(clazz)
&& isNotXpathFileGenerator(clazz);
}
/**
* Checks if the class has a default constructor.
* @param clazz class to check
* @return true if the class has a default constructor.
*/
private static boolean hasDefaultConstructor(Class clazz) {
boolean result = false;
for (Constructor constructor : clazz.getDeclaredConstructors()) {
if (constructor.getParameterCount() == 0) {
result = true;
break;
}
}
return result;
}
/**
* Checks whether a class may be considered as the checkstyle check
* which has TreeWalker as a parent.
* Checkstyle's checks are classes which implement 'AbstractCheck' interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle check.
*/
public static boolean isCheckstyleTreeWalkerCheck(Class clazz) {
return AbstractCheck.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class may be considered as the checkstyle file set.
* Checkstyle's file sets are classes which implement 'AbstractFileSetCheck' interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle file set.
*/
public static boolean isFileSetModule(Class clazz) {
return AbstractFileSetCheck.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class may be considered as the checkstyle filter.
* Checkstyle's filters are classes which implement 'Filter' interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle filter.
*/
public static boolean isFilterModule(Class clazz) {
return Filter.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class may be considered as the checkstyle file filter.
* Checkstyle's file filters are classes which implement 'BeforeExecutionFileFilter' interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle file filter.
*/
public static boolean isFileFilterModule(Class clazz) {
return BeforeExecutionFileFilter.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class may be considered as the checkstyle audit listener module.
* Checkstyle's audit listener modules are classes which implement 'AuditListener' interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle audit listener module.
*/
public static boolean isAuditListener(Class clazz) {
return AuditListener.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class may be considered as the checkstyle root module.
* Checkstyle's root modules are classes which implement 'RootModule' interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle root module.
*/
public static boolean isRootModule(Class clazz) {
return RootModule.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class may be considered as the checkstyle {@code TreeWalker} filter.
* Checkstyle's {@code TreeWalker} filters are classes which implement 'TreeWalkerFilter'
* interface.
* @param clazz class to check.
* @return true if a class may be considered as the checkstyle {@code TreeWalker} filter.
*/
public static boolean isTreeWalkerFilterModule(Class clazz) {
return TreeWalkerFilter.class.isAssignableFrom(clazz);
}
/**
* Checks whether a class is {@code XpathFileGeneratorAstFilter} or
* {@code XpathFileGeneratorAuditListener}.
* See issue #102 https://github.com/checkstyle/checkstyle/issues/102
* @param clazz class to check.
* @return true if a class name starts with `XpathFileGenerator`.
*/
private static boolean isNotXpathFileGenerator(Class clazz) {
return !clazz.getSimpleName().startsWith("XpathFileGenerator");
}
}