Java tutorial
/** * Licensed to Jasig under one or more contributor license * agreements. See the NOTICE file distributed with this work * for additional information regarding copyright ownership. * Jasig 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.jasig.schedassist.impl.caldav; import java.io.IOException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.http.HttpException; import org.apache.http.HttpRequest; import org.apache.http.HttpRequestInterceptor; import org.apache.http.auth.AuthScheme; import org.apache.http.auth.AuthScope; import org.apache.http.auth.AuthState; import org.apache.http.auth.Credentials; import org.apache.http.client.CredentialsProvider; import org.apache.http.client.protocol.ClientContext; import org.apache.http.protocol.HttpContext; /** * {@link HttpRequestInterceptor} that performs pre-emptive authentication. * * @author Nicholas Blair * @version $Id: CaldavCalendarDataImportServiceImpl.java $ */ class PreemptiveAuthInterceptor implements HttpRequestInterceptor { /** * */ static final String PREEMPTIVE_AUTH = "org.jasig.schedassist.impl.caldav.preemptive-auth"; private final AuthScope caldavAdminAuthScope; private final Log log = LogFactory.getLog(this.getClass()); /** * @param caldavAdminAuthScope */ public PreemptiveAuthInterceptor(AuthScope caldavAdminAuthScope) { this.caldavAdminAuthScope = caldavAdminAuthScope; } /* * (non-Javadoc) * @see org.apache.http.HttpRequestInterceptor#process(org.apache.http.HttpRequest, org.apache.http.protocol.HttpContext) */ public void process(final HttpRequest request, final HttpContext context) throws HttpException, IOException { AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE); if (authState.getAuthScheme() == null) { AuthScheme authScheme = (AuthScheme) context.getAttribute(PREEMPTIVE_AUTH); CredentialsProvider credsProvider = (CredentialsProvider) context .getAttribute(ClientContext.CREDS_PROVIDER); if (authScheme != null) { Credentials creds = credsProvider.getCredentials(caldavAdminAuthScope); if (creds == null) { throw new HttpException("No credentials for preemptive authentication"); } authState.setAuthScheme(authScheme); authState.setCredentials(creds); if (log.isTraceEnabled()) { log.trace("successfully set credentials " + creds + " and authScheme " + authScheme + " for request " + request); } } else { log.warn(PREEMPTIVE_AUTH + " authScheme not found in context, failed to set scheme and credentials for " + request); } } else { log.warn("context's authState attribute (" + authState + ") has non-null AuthScheme for request " + request); } } }