HTTPBasedAccessHandler.java

/***************************************************
*
* cismet GmbH, Saarbruecken, Germany
*
*              ... and it just works.
*
****************************************************/
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 * To change this template, choose Tools | Templates
 * and open the template in the editor.
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package de.cismet.security.handler;

import org.apache.commons.httpclient.Credentials;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
import org.apache.commons.httpclient.NTCredentials;
import org.apache.commons.httpclient.auth.AuthScope;
import org.apache.commons.httpclient.auth.CredentialsProvider;
import org.apache.log4j.Logger;

import java.net.URL;

import java.util.HashMap;
import java.util.Map;

import de.cismet.commons.security.handler.AbstractAccessHandler;

import de.cismet.netutil.Proxy;

import de.cismet.security.GUICredentialsProvider;
import de.cismet.security.WebAccessManager;

/**
 * DOCUMENT ME!
 *
 * @author   spuhl
 * @version  $Revision$, $Date$
 */
public abstract class HTTPBasedAccessHandler extends AbstractAccessHandler {

    //~ Static fields/initializers ---------------------------------------------

    private static final transient Logger LOG = Logger.getLogger(HTTPBasedAccessHandler.class);

    //~ Instance fields --------------------------------------------------------

    // do not use the url as key, because similar urls will did not be differentiated in the HashMap implementation
    // use the string representation of the urls instead.
    private final transient Map<String, GUICredentialsProvider> httpCredentialsForURLS;
    private transient Proxy proxy;

    //~ Constructors -----------------------------------------------------------

    /**
     * Sets the SystemProxy by default.
     */
    protected HTTPBasedAccessHandler() {
        if (LOG.isDebugEnabled()) {
            LOG.debug("HTTPBasedAccessHandler"); // NOI18N
        }
        httpCredentialsForURLS = new HashMap<String, GUICredentialsProvider>();
        proxy = Proxy.fromSystem();
    }

    //~ Methods ----------------------------------------------------------------

    /**
     * Returns a configured HttpClient with (if set) proxy settings.
     *
     * @return  configured HttpClient
     */
    protected HttpClient getConfiguredHttpClient() {
        if (LOG.isDebugEnabled()) {
            LOG.debug("getConfiguredHttpClient"); // NOI18N
        }

        final HttpClient client = new HttpClient(new MultiThreadedHttpConnectionManager());
        if (proxy != null) {
            client.getHostConfiguration().setProxy(proxy.getHost(), proxy.getPort());

            // proxy needs authentication
            if ((proxy.getUsername() != null) && (proxy.getPassword() != null)) {
                final AuthScope authscope = new AuthScope(proxy.getHost(), proxy.getPort());
                final Credentials credentials = new NTCredentials(proxy.getUsername(),
                        proxy.getPassword(),
                        "", // NOI18N
                        (proxy.getDomain() == null) ? "" : proxy.getDomain());
                client.getState().setProxyCredentials(authscope, credentials);
            }
        }

        return client;
    }

    /**
     * Proxy getter.
     *
     * @return  proxy
     */
    public Proxy getProxy() {
        return proxy;
    }

    /**
     * Proxy setter.
     *
     * @param  proxy  DOCUMENT ME!
     */
    public void setProxy(final Proxy proxy) {
        this.proxy = proxy;
    }

    /**
     * DOCUMENT ME!
     *
     * @param   url  DOCUMENT ME!
     *
     * @return  DOCUMENT ME!
     */
    protected HttpClient getSecurityEnabledHttpClient(final URL url) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("getSecurityEnabledHttpClient"); // NOI18N
        }
        final HttpClient client = getConfiguredHttpClient();
        client.getParams().setParameter(CredentialsProvider.PROVIDER, getCredentialProvider(url));

        return client;
    }

    /**
     * DOCUMENT ME!
     *
     * @param   url  DOCUMENT ME!
     *
     * @return  DOCUMENT ME!
     */
    protected CredentialsProvider getCredentialProvider(final URL url) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Retrieving Credential Provider for url: " + url); // NOI18N
        }

        GUICredentialsProvider cp = getHttpCredentialProviderURL(url);
        if (cp == null) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("no Credential Provider available for url: " + url);
            }
            cp = createSynchronizedCP(url);
        } else {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Credential Provider available for url: " + url);
            }
        }

        return cp;
    }

    /**
     * DOCUMENT ME!
     *
     * @param   url  DOCUMENT ME!
     *
     * @return  DOCUMENT ME!
     */
    public GUICredentialsProvider getHttpCredentialProviderURL(final URL url) {
        final GUICredentialsProvider cp = httpCredentialsForURLS.get(url.toString());

        return cp;
    }

    /**
     * DOCUMENT ME!
     *
     * @param   url  DOCUMENT ME!
     *
     * @return  DOCUMENT ME!
     */
    public synchronized GUICredentialsProvider createSynchronizedCP(final URL url) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Credential Provider should be created synchronously"); // NOI18N
        }

        GUICredentialsProvider cp = httpCredentialsForURLS.get(url.toString());
        if (cp == null) {
            cp = new GUICredentialsProvider(url, WebAccessManager.getInstance().getTopLevelComponent());
            if (LOG.isDebugEnabled()) {
                LOG.debug("A new Credential Provider instance was created for: " + url.toString()); // NOI18N
            }
            httpCredentialsForURLS.put(url.toString(), cp);
        } else {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Credential Provider was already available: " + url.toString());          // NOI18N
            }
        }

        return cp;
    }

    /**
     * DOCUMENT ME!
     */
    public void resetCredentials() {
        for (final GUICredentialsProvider prov : httpCredentialsForURLS.values()) {
            prov.setUsernamePassword(null);
        }
        httpCredentialsForURLS.clear();
    }
}