core/src/main/java/org/apache/any23/util/DiscoveryUtils.java - any23 - Git at Google

 /*
  * 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.any23.util;

 import java.io.File;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.net.URLDecoder;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;

 /**
  * This class provides utility methods
  * for discovering classes in packages.
  *
  * @author Michele Mostarda (mostarda@fbk.eu)
  */
 public class DiscoveryUtils {

     private static final String FILE_PREFIX  = "file:";
     private static final String CLASS_SUFFIX = ".class";


     /**
      * Scans all classes accessible from the context class loader
      * which belong to the given package and sub-packages.
      *
      * @param packageName the root package.
      * @return list of matching classes.
      */
     public static List<Class> getClassesInPackage(String packageName) {
         final ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
         assert classLoader != null;
         final String path = packageName.replace('.', '/');
         final Enumeration<URL> resources;
         try {
             resources = classLoader.getResources(path);
         } catch (IOException ioe) {
             throw new IllegalStateException("Error while retrieving internal resource path.", ioe);
         }
         final List<File> dirs = new ArrayList<File>();
         while (resources.hasMoreElements()) {
             final URL resource = resources.nextElement();
             final String fileName = resource.getFile();
             final String fileNameDecoded;
             try {
                 fileNameDecoded = URLDecoder.decode(fileName, "UTF-8");
             } catch (UnsupportedEncodingException uee) {
                 throw new IllegalStateException("Error while decoding class file name.", uee);
             }
             dirs.add( new File(fileNameDecoded) );
         }
         @SuppressWarnings("rawtypes")
         final ArrayList<Class> classes = new ArrayList<Class>();
         for (File directory : dirs) {
             classes.addAll(findClasses(directory, packageName) );
         }
         return classes;
     }

     /**
      * Scans all classes accessible from the context class loader
      * which belong to the given package and sub-packages and filter
      * them by ones implementing the specified interface <code>iface</code>.
      *
      * @param packageName the root package.
      * @param filter the interface/class filter.
      * @return list of matching classes.
      */
     public static List<Class> getClassesInPackage(String packageName, Class<?> filter) {
         final List<Class> classesInPackage = getClassesInPackage(packageName);
         @SuppressWarnings("rawtypes")
         final List<Class> result = new ArrayList<Class>();
         Class<?> superClazz;
         for(Class<?> clazz : classesInPackage) {
             if(clazz.equals(filter)) {
                 continue;
             }
             superClazz = clazz.getSuperclass();
             if( ( superClazz != null && superClazz.equals(filter) ) || contains(clazz.getInterfaces(), filter) ) {
                 result.add(clazz);
             }
         }
         return result;
     }

     /**
      * Find all classes within the specified location by package name.
      *
      * @param location class location.
      * @param packageName package name.
      * @return list of detected classes.
      */
     private static List<Class> findClasses(File location, String packageName) {
         final String locationPath = location.getPath();
         if( locationPath.indexOf(FILE_PREFIX) == 0 ) {
             return findClassesInJAR(locationPath);
         }
         return findClassesInDir(location, packageName);
     }

     /**
      * Find all classes within a JAR in a given prefix addressed with syntax
      * <code>file:<path/to.jar>!<path/to/package>.
      *
      * @param location package location.
      * @return list of detected classes.
      */
     private static List<Class> findClassesInJAR(String location) {
         final String[] sections = location.split("!");
         if(sections.length != 2) {
             throw new IllegalArgumentException("Invalid JAR location.");
         }
         final String jarLocation = sections[0].substring(FILE_PREFIX.length());
         final String packagePath = sections[1].substring(1);

         try {
             @SuppressWarnings("resource")
             final JarFile jarFile = new JarFile(jarLocation);
             final Enumeration<JarEntry> entries = jarFile.entries();
             @SuppressWarnings("rawtypes")
             final List<Class> result = new ArrayList<Class>();
             JarEntry current;
             String entryName;
             String clazzName;
             Class<?> clazz;
             while(entries.hasMoreElements()) {
                 current = entries.nextElement();
                 entryName = current.getName();
                 if(
                         StringUtils.isPrefix(packagePath, entryName)
                                 &&
                         StringUtils.isSuffix(CLASS_SUFFIX, entryName)
                                 &&
                         ! entryName.contains("$")
                 ) {
                     try {
                         clazzName = entryName.substring(
                                 0, entryName.length() - CLASS_SUFFIX.length()
                         ).replaceAll("/",".");
                         clazz = Class.forName(clazzName);
                     } catch (ClassNotFoundException cnfe) {
                         throw new IllegalStateException("Error while loading detected class.", cnfe);
                     }
                     result.add(clazz);
                 }
             }
             return result;
         } catch (IOException ioe) {
             throw new RuntimeException("Error while opening JAR file.", ioe);
         }
     }

     /**
      * Recursive method used to find all classes in a given directory and sub-dirs.
      *
      * @param directory   The base directory
      * @param packageName The package name for classes found inside the base directory
      * @return The classes
      */
     private static List<Class> findClassesInDir(File directory, String packageName) {
         if (!directory.exists()) {
             return Collections.emptyList();
         }
         @SuppressWarnings("rawtypes")
         final List<Class> classes = new ArrayList<Class>();
         File[] files = directory.listFiles();
         for (File file : files) {
             String fileName = file.getName();
             if (file.isDirectory()) {
                 assert !fileName.contains(".");
                 classes.addAll(findClassesInDir(file, packageName + "." + fileName));
             } else if (fileName.endsWith(".class") && !fileName.contains("$")) {
                 try {
                     Class<?> clazz;
                     try {
                         clazz = Class.forName(packageName + '.' + fileName.substring(0, fileName.length() - 6));
                     } catch (ExceptionInInitializerError e) {
                         /*
                         happen, for example, in classes, which depend on Spring to inject some beans,
                         and which fail, if dependency is not fulfilled
                         */
                         clazz = Class.forName(
                                 packageName + '.' + fileName.substring(0, fileName.length() - 6),
                                 false,
                                 Thread.currentThread().getContextClassLoader()
                         );
                     }
                     classes.add(clazz);
                 } catch (ClassNotFoundException cnfe) {
                     throw new IllegalStateException("Error while loading detected class.", cnfe);
                 }
             }
         }
         return classes;
     }

     private static boolean contains(Object[] list, Object t) {
         for(Object o : list) {
             if( o.equals(t) ) {
                 return true;
             }
         }
         return false;
     }

     private DiscoveryUtils(){}

 }
	/*
	* 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.any23.util;

	import java.io.File;
	import java.io.IOException;
	import java.io.UnsupportedEncodingException;
	import java.net.URL;
	import java.net.URLDecoder;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Enumeration;
	import java.util.List;
	import java.util.jar.JarEntry;
	import java.util.jar.JarFile;

	/**
	* This class provides utility methods
	* for discovering classes in packages.
	*
	* @author Michele Mostarda (mostarda@fbk.eu)
	*/
	public class DiscoveryUtils {

	private static final String FILE_PREFIX = "file:";
	private static final String CLASS_SUFFIX = ".class";


	/**
	* Scans all classes accessible from the context class loader
	* which belong to the given package and sub-packages.
	*
	* @param packageName the root package.
	* @return list of matching classes.
	*/
	public static List<Class> getClassesInPackage(String packageName) {
	final ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
	assert classLoader != null;
	final String path = packageName.replace('.', '/');
	final Enumeration<URL> resources;
	try {
	resources = classLoader.getResources(path);
	} catch (IOException ioe) {
	throw new IllegalStateException("Error while retrieving internal resource path.", ioe);
	}
	final List<File> dirs = new ArrayList<File>();
	while (resources.hasMoreElements()) {
	final URL resource = resources.nextElement();
	final String fileName = resource.getFile();
	final String fileNameDecoded;
	try {
	fileNameDecoded = URLDecoder.decode(fileName, "UTF-8");
	} catch (UnsupportedEncodingException uee) {
	throw new IllegalStateException("Error while decoding class file name.", uee);
	}
	dirs.add( new File(fileNameDecoded) );
	}
	@SuppressWarnings("rawtypes")
	final ArrayList<Class> classes = new ArrayList<Class>();
	for (File directory : dirs) {
	classes.addAll(findClasses(directory, packageName) );
	}
	return classes;
	}

	/**
	* Scans all classes accessible from the context class loader
	* which belong to the given package and sub-packages and filter
	* them by ones implementing the specified interface <code>iface</code>.
	*
	* @param packageName the root package.
	* @param filter the interface/class filter.
	* @return list of matching classes.
	*/
	public static List<Class> getClassesInPackage(String packageName, Class<?> filter) {
	final List<Class> classesInPackage = getClassesInPackage(packageName);
	@SuppressWarnings("rawtypes")
	final List<Class> result = new ArrayList<Class>();
	Class<?> superClazz;
	for(Class<?> clazz : classesInPackage) {
	if(clazz.equals(filter)) {
	continue;
	}
	superClazz = clazz.getSuperclass();
	if( ( superClazz != null && superClazz.equals(filter) ) \|\| contains(clazz.getInterfaces(), filter) ) {
	result.add(clazz);
	}
	}
	return result;
	}

	/**
	* Find all classes within the specified location by package name.
	*
	* @param location class location.
	* @param packageName package name.
	* @return list of detected classes.
	*/
	private static List<Class> findClasses(File location, String packageName) {
	final String locationPath = location.getPath();
	if( locationPath.indexOf(FILE_PREFIX) == 0 ) {
	return findClassesInJAR(locationPath);
	}
	return findClassesInDir(location, packageName);
	}

	/**
	* Find all classes within a JAR in a given prefix addressed with syntax
	* <code>file:<path/to.jar>!<path/to/package>.
	*
	* @param location package location.
	* @return list of detected classes.
	*/
	private static List<Class> findClassesInJAR(String location) {
	final String[] sections = location.split("!");
	if(sections.length != 2) {
	throw new IllegalArgumentException("Invalid JAR location.");
	}
	final String jarLocation = sections[0].substring(FILE_PREFIX.length());
	final String packagePath = sections[1].substring(1);

	try {
	@SuppressWarnings("resource")
	final JarFile jarFile = new JarFile(jarLocation);
	final Enumeration<JarEntry> entries = jarFile.entries();
	@SuppressWarnings("rawtypes")
	final List<Class> result = new ArrayList<Class>();
	JarEntry current;
	String entryName;
	String clazzName;
	Class<?> clazz;
	while(entries.hasMoreElements()) {
	current = entries.nextElement();
	entryName = current.getName();
	if(
	StringUtils.isPrefix(packagePath, entryName)
	&&
	StringUtils.isSuffix(CLASS_SUFFIX, entryName)
	&&
	! entryName.contains("$")
	) {
	try {
	clazzName = entryName.substring(
	0, entryName.length() - CLASS_SUFFIX.length()
	).replaceAll("/",".");
	clazz = Class.forName(clazzName);
	} catch (ClassNotFoundException cnfe) {
	throw new IllegalStateException("Error while loading detected class.", cnfe);
	}
	result.add(clazz);
	}
	}
	return result;
	} catch (IOException ioe) {
	throw new RuntimeException("Error while opening JAR file.", ioe);
	}
	}

	/**
	* Recursive method used to find all classes in a given directory and sub-dirs.
	*
	* @param directory The base directory
	* @param packageName The package name for classes found inside the base directory
	* @return The classes
	*/
	private static List<Class> findClassesInDir(File directory, String packageName) {
	if (!directory.exists()) {
	return Collections.emptyList();
	}
	@SuppressWarnings("rawtypes")
	final List<Class> classes = new ArrayList<Class>();
	File[] files = directory.listFiles();
	for (File file : files) {
	String fileName = file.getName();
	if (file.isDirectory()) {
	assert !fileName.contains(".");
	classes.addAll(findClassesInDir(file, packageName + "." + fileName));
	} else if (fileName.endsWith(".class") && !fileName.contains("$")) {
	try {
	Class<?> clazz;
	try {
	clazz = Class.forName(packageName + '.' + fileName.substring(0, fileName.length() - 6));
	} catch (ExceptionInInitializerError e) {
	/*
	happen, for example, in classes, which depend on Spring to inject some beans,
	and which fail, if dependency is not fulfilled
	*/
	clazz = Class.forName(
	packageName + '.' + fileName.substring(0, fileName.length() - 6),
	false,
	Thread.currentThread().getContextClassLoader()
	);
	}
	classes.add(clazz);
	} catch (ClassNotFoundException cnfe) {
	throw new IllegalStateException("Error while loading detected class.", cnfe);
	}
	}
	}
	return classes;
	}

	private static boolean contains(Object[] list, Object t) {
	for(Object o : list) {
	if( o.equals(t) ) {
	return true;
	}
	}
	return false;
	}

	private DiscoveryUtils(){}

	}