de.micromata.genome.util.runtime.DynamicClassPath.java Source code

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Here is the source code for de.micromata.genome.util.runtime.DynamicClassPath.java

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//
// Copyright (C) 2010-2016 Micromata GmbH
//
// 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.
//

package de.micromata.genome.util.runtime;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;

import org.apache.commons.lang3.StringUtils;

import de.micromata.genome.util.bean.PrivateBeanUtils;
import de.micromata.genome.util.runtime.LocalSettings;

/**
 * Utility to dynamically extend the class path.
 * 
 * TODO RK read Local Settings.
 * 
 * @author Roger Rene Kommer (r.kommer.extern@micromata.de)
 *
 */
public class DynamicClassPath {
    public static void initClassPath(LocalSettings localSettings) {
        String cp = localSettings.getProperty("sys.classpathext");
        if (StringUtils.isBlank(cp) == true) {
            return;
        }
        String[] cpl = StringUtils.split(cp, ",");
        URL[] urls = new URL[cpl.length];
        for (int i = 0; i < cpl.length; ++i) {
            URL url = createClUrl(new File(cpl[i]));
            urls[i] = url;
        }
        boolean extendSystemCl = false;
        if (extendSystemCl == false) {
            addContextClassPathes(urls);
        } else {
            for (String c : cpl) {
                URL url = createClUrl(new File(c));
                addSystemClassPath(url);
            }
        }
        // Class cls = Class.forName("org.springbyexample.jdbc.datasource.InitializingBasicDataSource", true, Thread.currentThread()
        // .getContextClassLoader());
    }

    public static void addSystemClassPath(URL url) {
        URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
        PrivateBeanUtils.invokeMethod(sysloader, "addURL", url);
    }

    public static void addContextClassPathes(URL[] urls) {
        URLClassLoader urlClassLoader = new URLClassLoader(urls, Thread.currentThread().getContextClassLoader());
        Thread.currentThread().setContextClassLoader(urlClassLoader);
    }

    public static URL createClUrl(File f) {
        try {
            URL ret;
            if (f.isDirectory() == true) {
                ret = f.toURI().toURL();
            } else {
                // ret = new URL("jar", "", f.getAbsolutePath());
                ret = f.toURI().toURL();
            }
            String s = ret.toExternalForm();
            return ret;
        } catch (MalformedURLException ex) {
            throw new RuntimeException("Cannot extend class oath because of invalid url: " + f.toURI());
        }
    }
}