/*
 * Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * Licensed 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.springframework.security.web.authentication.www;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;

/**
 * Used by the <code>ExceptionTraslationFilter</code> to commence authentication via the
 * {@link BasicAuthenticationFilter}.
 * <p>
 * Once a user agent is authenticated using BASIC authentication, logout requires that the
 * browser be closed or an unauthorized (401) header be sent. The simplest way of
 * achieving the latter is to call the
 * {@link #commence(HttpServletRequest, HttpServletResponse, AuthenticationException)}
 * method below. This will indicate to the browser its credentials are no longer
 * authorized, causing it to prompt the user to login again.
 *
 * @author Ben Alex
 */
public class BasicAuthenticationEntryPoint implements AuthenticationEntryPoint,
		InitializingBean {
	// ~ Instance fields
	// ================================================================================================

	private String realmName;

	// ~ Methods
	// ========================================================================================================

	public void afterPropertiesSet() throws Exception {
		Assert.hasText(realmName, "realmName must be specified");
	}

	public void commence(HttpServletRequest request, HttpServletResponse response,
			AuthenticationException authException) throws IOException, ServletException {
		response.addHeader("WWW-Authenticate", "Basic realm=\"" + realmName + "\"");
		response.sendError(HttpServletResponse.SC_UNAUTHORIZED,
				authException.getMessage());
	}

	public String getRealmName() {
		return realmName;
	}

	public void setRealmName(String realmName) {
		this.realmName = realmName;
	}

}
