递归获取给定包和所有子包中所有类的列表。
/*来自 时 代 J a v a 公 众 号*/ /* * Copyright (c) 2012 Data Harmonisation Panel * * All rights reserved. This program and the accompanying materials are made * available under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation, either version 3 of the License, * or (at your option) any later version. * * You should have received a copy of the GNU Lesser General Public License * along with this distribution. If not, see <http://www.gnu.org/licenses/>. * * Contributors: * HUMBOLDT EU Integrated Project #030962 * Data Harmonisation Panel <http://www.dhpanel.eu> */ import java.io.File; import java.io.IOException; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.net.JarURLConnection; import java.net.MalformedURLException; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.util.ArrayList; import java.util.Collection; import java.util.Enumeration; import java.util.Iterator; import java.util.List; import java.util.jar.JarEntry; import java.util.jar.JarFile; import java.util.zip.ZipException; /** nowjava.com - 时 代 Java 提供 **/ public class Main{ /** * The package resolver used to retrieve URLs to packages */ private static PackageResolver _packageResolver = new DefaultPackageResolver(); /** * Gets a list of all classes in the given package and all subpackages * recursively. * * @param pkg the package * @param classLoader the class loader to use * @return the list of classes * @throws IOException if a subpackage or a class could not be loaded */ public static List<Class<?>> getClassesFromPackage(String pkg, ClassLoader classLoader) throws IOException { return getClassesFromPackage(pkg, classLoader, true); } /** * Gets a list of all classes in the given package * * @param pkg the package * @param classLoader the class loader to use * @param recursive true if all subpackages shall be traversed too * @return the list of classes * @throws IOException if a subpackage or a class could not be loaded */ public static List<Class<?>> getClassesFromPackage(String pkg, ClassLoader classLoader, boolean recursive) throws IOException { List<Class<?>> result = new ArrayList<Class<?>>(); getClassesFromPackage(pkg, result, classLoader, recursive); return result; } private static void getClassesFromPackage(String pkg, List<Class<?>> l, ClassLoader classLoader, boolean recursive) throws IOException { File[] files = getFilesFromPackage(pkg); for (File f : files) { String name = f.getName(); if (f.isDirectory() && recursive) { if (!name.startsWith(".")) { //$NON-NLS-1$ getClassesFromPackage( pkg + "." + name, l, classLoader, true); //$NON-NLS-1$ } } else if (name.toLowerCase().endsWith(".class")) { //$NON-NLS-1$ // the following lines make sure we also handle classes // in subpackages. These subpackages may be returned by // ApplicationContext.getFilesFromPackage() when we are // in a jar file String classPath = f.toURI().toString().replace('/', '.') .replace('\\', '.'); String className = classPath.substring( classPath.lastIndexOf(pkg), classPath.lastIndexOf('.')); Class<?> c; try { c = Class.forName(className, true, classLoader); } catch (ClassNotFoundException e) { throw new IOException("Could not load class: " + //$NON-NLS-1$ e.getMessage()); } l.add(c); } } } /** * Returns an array of all files contained by a given package * * @param pkg the package (e.g. "de.igd.fhg.CityServer3D") * @return an array of files * @throws IOException if the package could not be found */ public static synchronized File[] getFilesFromPackage(String pkg) throws IOException { File[] files; JarFile jarFile = null; try { URL u = _packageResolver.resolve(pkg); if (u != null && !u.toString().startsWith("jar:")) { //$NON-NLS-1$ // we got the package as an URL. Simply create a file // from this URL File dir; try { dir = new File(u.toURI()); } catch (URISyntaxException e) { // if the URL contains spaces and they have not been // replaced by %20 then we'll have to use the following line dir = new File(u.getFile()); } if (!dir.isDirectory()) { // try another method dir = new File(u.getFile()); } files = null; if (dir.isDirectory()) { files = dir.listFiles(); } } else { // the package may be in a jar file // get the current jar file and search it if (u != null && u.toString().startsWith("jar:file:")) { //$NON-NLS-1$ // first try using URL and File try { String p = u.toString().substring(4); p = p.substring(0, p.indexOf("!/")); //$NON-NLS-1$ File file = new File(URI.create(p)); p = file.getAbsolutePath(); try { jarFile = new JarFile(p); } catch (ZipException e) { throw new IllegalArgumentException( "No zip file: " + p, e); //$NON-NLS-1$ } } catch (Throwable e1) { // second try directly using path String p = u.toString().substring(9); p = p.substring(0, p.indexOf("!/")); //$NON-NLS-1$ try { jarFile = new JarFile(p); } catch (ZipException e2) { throw new IllegalArgumentException( "No zip file: " + p, e2); //$NON-NLS-1$ } } } else { u = getCurrentJarURL(); // open jar file JarURLConnection juc = (JarURLConnection) u .openConnection(); jarFile = juc.getJarFile(); } // enumerate entries and add those that match the package path Enumeration<JarEntry> entries = jarFile.entries(); ArrayList<String> file_names = new ArrayList<String>(); String package_path = pkg.replaceAll("\\.", "/"); //$NON-NLS-1$ //$NON-NLS-2$ boolean slashed = false; if (package_path.charAt(0) == '/') { package_path = package_path.substring(1); slashed = true; } while (entries.hasMoreElements()) { JarEntry j = entries.nextElement(); if (j.getName().matches("^" + package_path + ".+\\..+")) { //$NON-NLS-1$ //$NON-NLS-2$ if (slashed) { file_names.add("/" + j.getName()); //$NON-NLS-1$ } else { file_names.add(j.getName()); } } } // convert list to array files = new File[file_names.size()]; Iterator<String> i = file_names.iterator(); int n = 0; while (i.hasNext()) { files[n++] = new File(