Java Class from Package getClassNamesForPackage(final Package p)

Description

get Class Names For Package

License

Apache License

Declaration

public static List<String> getClassNamesForPackage(final Package p) 

Method Source Code

//package com.java2s;
/*//from   w  w  w .j  av a  2  s.  c om
 * Copyright (c) 2002-2012 Gargoyle Software 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.
 */

import java.io.File;
import java.io.IOException;

import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class Main {
    public static List<String> getClassNamesForPackage(final Package p) {
        final List<String> classes = new ArrayList<String>();

        final String name = p.getName();
        final String path = name.replace('.', '/');

        final URL resource = ClassLoader.getSystemClassLoader().getResource(path);

        if (resource.toString().startsWith("jar:")) {
            processJar(resource, name, classes);
        } else {
            processDirectory(new File(resource.getPath()), name, classes);
        }

        return classes;
    }

    private static void processJar(URL url, String packageName, List<String> classes) {
        String relPath = packageName.replace('.', '/');
        String resPath = url.getPath();
        String jarPath = resPath.replaceFirst("[.]jar[!].*", ".jar").replaceFirst("file:", "");
        JarFile jarFile;
        try {
            jarFile = new JarFile(jarPath);
        } catch (IOException e) {
            throw new RuntimeException("Unexpected IOException reading JAR File '" + jarPath + "'", e);
        }
        for (Enumeration<JarEntry> entries = jarFile.entries(); entries.hasMoreElements();) {
            final JarEntry entry = entries.nextElement();
            String entryName = entry.getName();
            String className = null;
            if (entryName.endsWith(".class") && entryName.startsWith(relPath)
                    && entryName.length() > (relPath.length() + "/".length())) {
                className = entryName.replace('/', '.').replace('\\', '.').replace(".class", "");
            }
            if (className != null) {
                classes.add(className);
            }
        }
    }

    private static void processDirectory(File directory, String pkgname, List<String> classes) {
        String[] files = directory.list();
        for (int i = 0; i < files.length; i++) {
            String fileName = files[i];
            String className = null;
            if (fileName.endsWith(".class")) {
                className = pkgname + '.' + fileName.substring(0, fileName.length() - 6);
            }
            if (className != null) {
                classes.add(className);
            }
            final File subdir = new File(directory, fileName);
            if (subdir.isDirectory()) {
                processDirectory(subdir, pkgname + '.' + fileName, classes);
            }
        }
    }
}

Related

1. getClassesInPackage(String packageName)
2. getClassesInPackage(String pckgname)
3. getClassesInPackage(String targetPackage)
4. getClassNameByPackage(String packageName)
5. getClassNamesByPkg(String pkg)
6. getClassNamesFromPackage(String packageName)
7. getClassNamesFromPackage(String packageName)
8. getClassNamesFromPackage(String packageName)
9. getClassNamesPackage(String pckgname)