/**
 * 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.xbean.finder;

import java.net.URL;
import java.net.MalformedURLException;
import java.util.Collection;
import java.util.List;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Map;
import java.util.HashMap;
import java.util.Arrays;
import java.io.IOException;
import java.io.File;

/**
 * @version $Rev$ $Date$
 */
public class UrlSet {

    private final Map<String,URL> urls;

    public UrlSet(ClassLoader classLoader) throws IOException {
        this(getUrls(classLoader));
    }

    public UrlSet(URL... urls){
        this(Arrays.asList(urls));
    }
    /**
     * Ignores all URLs that are not "jar" or "file"
     * @param urls
     */
    public UrlSet(Collection<URL> urls){
        this.urls = new HashMap<String,URL>();
        for (URL location : urls) {
            try {
//                if (location.getProtocol().equals("file")) {
//                    try {
//                        // See if it's actually a jar
//                        URL jarUrl = new URL("jar", "", location.toExternalForm() + "!/");
//                        JarURLConnection juc = (JarURLConnection) jarUrl.openConnection();
//                        juc.getJarFile();
//                        location = jarUrl;
//                    } catch (IOException e) {
//                    }
//                    this.urls.put(location.toExternalForm(), location);
//                }
                this.urls.put(location.toExternalForm(), location);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    private UrlSet(Map<String, URL> urls) {
        this.urls = urls;
    }

    public UrlSet include(UrlSet urlSet){
        Map<String, URL> urls = new HashMap<String, URL>(this.urls);
        urls.putAll(urlSet.urls);
        return new UrlSet(urls);
    }

    public UrlSet exclude(UrlSet urlSet) {
        Map<String, URL> urls = new HashMap<String, URL>(this.urls);
        Map<String, URL> parentUrls = urlSet.urls;
        for (String url : parentUrls.keySet()) {
            urls.remove(url);
        }
        return new UrlSet(urls);
    }

    public UrlSet exclude(ClassLoader parent) throws IOException {
        return exclude(new UrlSet(parent));
    }

    public UrlSet exclude(File file) throws MalformedURLException {
        return exclude(relative(file));
    }

    public UrlSet exclude(String pattern) throws MalformedURLException {
        return exclude(matching(pattern));
    }

    /**
     * Calls excludePaths(System.getProperty("java.ext.dirs"))
     * @return
     * @throws MalformedURLException
     */
    public UrlSet excludeJavaExtDirs() throws MalformedURLException {
        return excludePaths(System.getProperty("java.ext.dirs", ""));
    }

    /**
     * Calls excludePaths(System.getProperty("java.endorsed.dirs"))
     *
     * @return
     * @throws MalformedURLException
     */
    public UrlSet excludeJavaEndorsedDirs() throws MalformedURLException {
        return excludePaths(System.getProperty("java.endorsed.dirs", ""));
    }

    public UrlSet excludeJavaHome() throws MalformedURLException {
        String path = System.getProperty("java.home");

        File java = new File(path);

        if (path.matches("/System/Library/Frameworks/JavaVM.framework/Versions/[^/]+/Home")){
            java = java.getParentFile();
        }

        return exclude(java);
    }

    public UrlSet excludePaths(String pathString) throws MalformedURLException {
        String[] paths = pathString.split(File.pathSeparator);
        UrlSet urlSet = this;
        for (String path : paths) {
            File file = new File(path);
            urlSet = urlSet.exclude(file);
        }
        return urlSet;
    }

    public UrlSet matching(String pattern) {
        Map<String, URL> urls = new HashMap<String, URL>();
        for (Map.Entry<String, URL> entry : this.urls.entrySet()) {
            String url = entry.getKey();
            if (url.matches(pattern)){
                urls.put(url, entry.getValue());
            }
        }
        return new UrlSet(urls);
    }

    public UrlSet relative(File file) throws MalformedURLException {
        String urlPath = file.toURL().toExternalForm();
        Map<String, URL> urls = new HashMap<String, URL>();
        for (Map.Entry<String, URL> entry : this.urls.entrySet()) {
            String url = entry.getKey();
            if (url.startsWith(urlPath) || url.startsWith("jar:"+urlPath)){
                urls.put(url, entry.getValue());
            }
        }
        return new UrlSet(urls);
    }

    public List<URL> getUrls() {
        return new ArrayList<URL>(urls.values());
    }

    private static List<URL> getUrls(ClassLoader classLoader) throws IOException {
        List<URL> list = new ArrayList<URL>();
        ArrayList<URL> urls = Collections.list(classLoader.getResources("META-INF"));
        for (URL url : urls) {
            String externalForm = url.toExternalForm();
            int i = externalForm.lastIndexOf("META-INF");
            externalForm = externalForm.substring(0, i);
            url = new URL(externalForm);
            list.add(url);
        }
        list.addAll(Collections.list(classLoader.getResources("")));
        return list;
    }
}

@@ -3514,36 +3514,33 @@
         
-return excludePaths(
+String extDirs = 
 System.g
@@ -3561,29 +3561,87 @@
 va.ext.dirs%22
-, %22%22)
+);%0A        return extDirs == null ? this : excludePaths(extDirs
 );%0A    %7D%0A%0A  
@@ -3868,28 +3868,30 @@
     
-return excludePaths(
+String endorsedDirs = 
 Syst
@@ -3929,13 +3929,81 @@
 irs%22
-, %22%22)
+);%0A        return endorsedDirs == null ? this : excludePaths(endorsedDirs
 );%0A 

Patch from Andreas Veithen, for XBEAN-92: UrlSet excludePaths() method throws a nullpointer which is IBM JDK specific. Thanks, Andreas!