com.taobao.datax.engine.schedule.JarLoader.java Source code

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Here is the source code for com.taobao.datax.engine.schedule.JarLoader.java

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/**
 * (C) 2010-2011 Alibaba Group Holding Limited.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License 
 * version 2 as published by the Free Software Foundation. 
 * 
 */

package com.taobao.datax.engine.schedule;

import com.taobao.datax.common.exception.DataExchangeException;
import com.taobao.datax.common.exception.ExceptionTracker;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;

import java.io.File;
import java.io.FileFilter;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class JarLoader extends URLClassLoader {

    private static Logger logger = Logger.getLogger(JarLoader.class);

    public JarLoader(String[] paths) {
        this(paths, JarLoader.class.getClassLoader());
    }

    public JarLoader(String[] paths, ClassLoader parent) {
        super(getUrls(paths), parent);
    }

    private static URL[] getUrls(String[] paths) {
        if (null == paths || 0 == paths.length) {
            throw new IllegalArgumentException("Paths cannot be empty .");
        }

        List<URL> urls = new ArrayList<URL>();
        for (String path : paths) {
            urls.addAll(Arrays.asList(getUrl(path)));
        }

        return urls.toArray(new URL[0]);
    }

    private static URL[] getUrl(String path) {
        /* check path exist */
        if (null == path || StringUtils.isBlank(path)) {
            throw new IllegalArgumentException("Path cannot be empty .");
        }

        File jarPath = new File(path);
        if (!jarPath.exists() || !jarPath.isDirectory()) {
            throw new IllegalArgumentException("Path must be directory .");
        }

        /* set filter */
        FileFilter jarFilter = new FileFilter() {
            @Override
            public boolean accept(File pathname) {
                return pathname.getName().endsWith(".jar");
            }
        };

        /* iterate all jar */
        File[] allJars = new File(path).listFiles(jarFilter);
        URL[] jarUrls = new URL[allJars.length];

        for (int i = 0; i < allJars.length; i++) {
            try {
                jarUrls[i] = allJars[i].toURI().toURL();
            } catch (MalformedURLException e) {
                logger.error(ExceptionTracker.trace(e));
                throw new DataExchangeException(e.getCause());
            }
            logger.debug(jarUrls[i]);
        }

        return jarUrls;
    }

}