Apache CXF example source code file (PlugInClassLoader.java)

This example Apache CXF source code file (PlugInClassLoader.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Apache CXF tags/keywords

file_colon, filters_props_file, io, ioexception, ioexception, jars_props_file, log, nefilters_props_file, net, network, pluginclassloader, properties, properties, security, string, string, url, url, url_scheme_colon, util

The Apache CXF PlugInClassLoader.java source code

/**
 * 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.cxf.jca.core.classloader;


import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.ProtectionDomain;
import java.security.SecureClassLoader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.logging.Logger;

import org.apache.cxf.common.classloader.FireWallClassLoader;
import org.apache.cxf.common.logging.LogUtils;


public class PlugInClassLoader extends SecureClassLoader {
    private static final Logger LOG =  LogUtils.getL7dLogger(PlugInClassLoader.class);
    private static final String FILE_COLON = "file:";
    private static final String ZIP_COLON = "zip:";
    private static final String URL_SCHEME_COLON = "classloader:";
    private static final String JARS_PROPS_FILE = "jars.properties";
    private static final String FILTERS_PROPS_FILE = "filters.properties";
    private static final String NEFILTERS_PROPS_FILE = "negativefilters.properties";
    private String jarUrls[] = new String[0];
    private final ProtectionDomain protectionDomain;
    
    private ClassLoader ploader;

    public PlugInClassLoader(ClassLoader p) throws IOException {        
        super(new FireWallClassLoader(p, 
                                      getFilterList(p, FILTERS_PROPS_FILE),
                                      getFilterList(p, NEFILTERS_PROPS_FILE)));
        ploader = p;
        protectionDomain = getClass().getProtectionDomain();
        jarUrls = loadUrls(p);
        processJarUrls(jarUrls);
    }

    private void processJarUrls(String urls[]) {
        for (int i = 0; i < urls.length; i++) {
            if (urls[i].startsWith(ZIP_COLON)) {
                urls[i] = FILE_COLON + urls[i].substring(ZIP_COLON.length());                              
            }
        }
    }

    private static String[] getFilterList(ClassLoader parent, String propFile) throws IOException {
        Properties filtersProps = getProperties(parent, propFile);
        Iterator<Object> i = filtersProps.keySet().iterator();
        while (i.hasNext()) {            
            LOG.config("get Filter " + propFile + "::" + (String)i.next());            
        }    
        return (String[])filtersProps.keySet().toArray(new String[] {});
    }

    private static Properties getProperties(ClassLoader parent, String propsFileName) throws IOException {
        InputStream in = parent.getResourceAsStream(propsFileName);

        if (null == in) {
            in = PlugInClassLoader.class.getResourceAsStream(propsFileName);

            if (null == in) {
                String msg = "Internal rar classloader failed to locate configuration resource: "
                        + propsFileName;
                IOException ioe = new IOException(msg);

                LOG.warning(ioe.toString());
                throw ioe;
            }
        }

        Properties props = new Properties();

        props.load(in);
        LOG.fine("Contents: " + propsFileName + props);

        return props;
    }

    private String[] loadUrls(ClassLoader parent) throws IOException {
        List<String> urlList = new ArrayList();

        Properties props = getProperties(parent, JARS_PROPS_FILE);

        LOG.fine(props.toString());

        Enumeration keys = props.keys();

        while (keys.hasMoreElements()) {
            String key = (String)keys.nextElement();
            URL url = parent.getResource(key);

            if (url != null) {
                LOG.config(url.toString());
                urlList.add(url.toString());
            }
        }

        return (String[])urlList.toArray(new String[] {});
    }

    protected Class<?> findClass(String name) throws ClassNotFoundException {
        String path = name.replace('.', '/').concat(".class");
        LOG.fine("findClass " + path);
        byte bytes[] = null;

        for (int i = 0; i < jarUrls.length; i++) {
            String fullpath = jarUrls[i] + "!/" + path;           
            try {
                bytes = PlugInClassLoaderHelper.getResourceAsBytes(fullpath);

                if (bytes != null) {
                    break;
                }
            } catch (IOException ex) {
                // we should find everything we look for but if we don't our
                // parent can when we throw cnf below
                LOG.fine("findClass: " + name + ": " + ex.toString());
            }
        }

        if (bytes != null) {
            return defineClass(name, bytes, 0, bytes.length, protectionDomain);
        } else {
            LOG.config("can't find name " + name + " , try to using the ploader");
            Class<?> result = ploader.loadClass(name);
            if (null == result) {
                throw new ClassNotFoundException(name);
            } else {
                return result;
            }                
        }
    }
    
   
    protected URL findResource(String name) {
        LOG.fine("findResource: " + name);
        for (int i = 0; i < jarUrls.length; i++) {
            String fullpath = jarUrls[i] + "!/" + name;         
              
            if (PlugInClassLoaderHelper.hasResource(fullpath)) {                
                return genURL(fullpath);
            }
        }
        
        return null;
    }

    protected URL genURL(String path) {
        URL url = null;
        String urlString = URL_SCHEME_COLON + path;

        try {
            url = new URL(null, urlString, new Handler());
        } catch (MalformedURLException mue) {
            LOG.warning(mue.toString());
        }

        return url;
    }
}