RestFilter.java

/*******************************************************************************
 * Copyright (c) 2010-2014 SAP 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:
 *     SAP AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.skalli.view.internal.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.eclipse.skalli.view.Consts;

/**
 * This filter forwards the request to the REST API if an <tt>"Accept"</tt> header
 * with the value <tt>"text/xml"</tt> is present.
 */
public class RestFilter implements Filter {

    @Override
    public void destroy() {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
            ServletException {

        HttpServletRequest httpRequest = (HttpServletRequest) request;
        HttpServletResponse httpResponse = (HttpServletResponse) response;

        String requestURI = httpRequest.getRequestURI();
        String acceptHeader = httpRequest.getHeader("Accept"); //$NON-NLS-1$
        if (StringUtils.equals(acceptHeader, "text/xml")) { //$NON-NLS-1$
            httpResponse.sendRedirect(Consts.URL_REST_API + requestURI);
            return;
        }

        // proceed along the chain
        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
    }

}