ProxyBypass.java

/*******************************************************************************
 * Copyright (c) 2007, 2008 compeople AG and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * 	compeople AG (Stefan Liebig) - initial API and implementation
 *******************************************************************************/
package de.compeople.commons.net.proxy.win32;

import static com.google.common.base.Strings.nullToEmpty;

import java.net.URI;
import java.util.regex.Pattern;

/**
 * Encapsulates the proxy bypass list.
 * 
 * <br>
 * From MS WinHttp documentation of the WINHTTP_PROXY_INFO structure:<br>
 * <ul>
 * <li>The proxy server list contains one or more of the following strings
 * separated by semicolons or whitespace. <br>
 * ([<scheme>=][<scheme>"://"]<server>[":"<port>])</li>
 * <li>The proxy bypass list contains one or more server names separated by
 * semicolons or whitespace. The proxy bypass list can also contain the string
 * "<local>" to indicate that all local intranet sites are bypassed. Local
 * intranet sites are considered to be all servers that do not contain a period
 * in their name.</li>
 * </ul>
 */
class ProxyBypass {

    private final String proxyBypass;
    private final Pattern proxyBypassPattern;

    private final static String BYPASS_LOCAL_ADDESSES_TOKEN = "<local>";

    /**
     * Create a ProxyBypass instance from the proxy bypass list string.
     * 
     * @param proxyBypass
     */
    public ProxyBypass(String proxyBypass) {
        this.proxyBypass = nullToEmpty(proxyBypass);

        String regExp = proxyBypass.replace(";", "|").replace(".", "\\.").replace("*", ".*");
        this.proxyBypassPattern = Pattern.compile(regExp);
    }

    /**
     * Check whether the given uri should bypass the proxy.
     * 
     * @param uri
     * @return
     */
    public boolean bypassProxyFor(URI uri) {
        return (uri.getHost() != null)
                && (!uri.getHost().contains(".") && proxyBypass.contains(BYPASS_LOCAL_ADDESSES_TOKEN))
                || proxyBypassPattern.matcher(uri.getHost()).matches();
    }

}