Java ClassPath Get getClasspath(ClassLoader loader)

Description

get Classpath

License

Apache License

Declaration

public static String getClasspath(ClassLoader loader) 

Method Source Code

//package com.java2s;
/**/*from  w ww  .j  a  v  a 2s. c o  m*/
 *  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.
 */

import java.io.File;

import java.net.URL;
import java.net.URLClassLoader;

import java.util.LinkedHashSet;

import java.util.Set;

public class Main {
    public static String getClasspath(ClassLoader loader) {
        Set<URL> jars = getClassLoaderClasspath(loader);
        return buildClasspath(jars);
    }

    public static Set<URL> getClassLoaderClasspath(ClassLoader loader) {
        LinkedHashSet<URL> jars = new LinkedHashSet<URL>();
        getClassLoaderClasspath(loader, jars);
        return jars;
    }

    public static void getClassLoaderClasspath(ClassLoader loader, LinkedHashSet<URL> classpath) {
        if (loader == null || loader == ClassLoader.getSystemClassLoader()) {
            return;
            //        } else if (loader instanceof MultiParentClassLoader) {
            //            MultiParentClassLoader cl = (MultiParentClassLoader)loader;
            //            for (ClassLoader parent : cl.getParents()) {
            //                getClassLoaderClasspath(parent, classpath);
            //            }
            //            for (URL u : cl.getURLs()) {
            //                classpath.add(u);
            //            }
        } else if (loader instanceof URLClassLoader) {
            URLClassLoader cl = (URLClassLoader) loader;
            getClassLoaderClasspath(cl.getParent(), classpath);
            for (URL u : cl.getURLs()) {
                classpath.add(u);
            }
        } else {
            getClassLoaderClasspath(loader.getParent(), classpath);
        }
    }

    public static String buildClasspath(Set<URL> files) {
        StringBuilder classpath = new StringBuilder();
        buildClasspath(files, classpath);
        return classpath.toString();
    }

    public static void buildClasspath(Set<URL> files, StringBuilder classpath) {
        for (URL url : files) {
            if ("file".equals(url.getProtocol())) {
                String path = toFileName(url);
                classpath.append(path);
                classpath.append(File.pathSeparator);
            }
        }
    }

    public static String toFileName(URL url) {
        String filename = url.getFile().replace('/', File.separatorChar);
        int pos = 0;
        while ((pos = filename.indexOf('%', pos)) >= 0) {
            if (pos + 2 < filename.length()) {
                String hexStr = filename.substring(pos + 1, pos + 3);
                char ch = (char) Integer.parseInt(hexStr, 16);
                filename = filename.substring(0, pos) + ch + filename.substring(pos + 3);
            }
        }
        return filename;
    }
}

Related

1. getClasspath()
2. getClasspath()
3. getClassPath(Class c)
4. getClassPath(Class clazz)
5. getClasspath(ClassLoader classLoader)
6. getClassPath(ClassLoader loader)
7. getClassPath(File dir)
8. getClassPath(Object obj, boolean bOnlyPath)
9. getClassPath(String packageName, String name)