jena-fuseki2/jena-fuseki-core/src/main/java/org/apache/jena/fuseki/servlets/ResponseOps.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.apache.jena.fuseki.servlets;

import java.io.IOException;
import java.util.Locale;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.jena.riot.WebContent;
import org.apache.jena.riot.web.HttpNames;

class ResponseOps {
    // Helpers
    public static void put(Map<String, String> map, String key, String value) {
        map.put(key.toLowerCase(Locale.ROOT), value);
    }

    public static boolean isEOFexception(IOException ioEx) {
        if ( ioEx.getClass().getName().equals("org.mortbay.jetty.EofException eofEx") )
            return true;
        if ( ioEx instanceof java.io.EOFException )
            return true;
        return false;
    }

    public static String paramForceAccept(HttpServletRequest request) {
        String x = fetchParam(request, HttpNames.paramForceAccept);
        return x;
    }

    public static String paramStylesheet(HttpServletRequest request) {
        return fetchParam(request, HttpNames.paramStyleSheet);
    }

    public static String paramOutput(HttpServletRequest request, Map<String, String> map) {
        // Two names.
        String x = fetchParam(request, HttpNames.paramOutput1);
        if ( x == null )
            x = fetchParam(request, HttpNames.paramOutput2);
        return expandShortName(x, map);
    }

    public static String expandShortName(String str, Map<String, String> map) {
        if ( str == null )
            return null;
        // Force keys to lower case. See put() above.
        String key = str.toLowerCase(Locale.ROOT);
        String str2 = map.get(key);
        if ( str2 == null )
            return str;
        return str2;
    }

    public static String paramCallback(HttpServletRequest request) {
        return fetchParam(request, HttpNames.paramCallback);
    }

    public static String fetchParam(HttpServletRequest request, String parameterName) {
        String value = request.getParameter(parameterName);
        if ( value != null ) {
            value = value.trim();
            if ( value.length() == 0 )
                value = null;
        }
        return value;
    }

    /** Basic settings, including Content-Type, for a response. */
    public static void setHttpResponse(HttpAction action, String contentType, String charset) {
        // ---- Set up HTTP Response
        // Stop caching (not that ?queryString URLs are cached anyway)
        if ( true )
            ServletOps.setNoCache(action);
        // See: http://www.w3.org/International/O-HTTP-charset.html
        if ( contentType != null ) {
            if ( charset != null && !isXML(contentType) )
                contentType = contentType + "; charset=" + charset;
            action.log.trace("Content-Type for response: " + contentType);
            action.response.setContentType(contentType);
        }
    }

    public static boolean isXML(String contentType) {
        return contentType.equals(WebContent.contentTypeRDFXML) || contentType.equals(WebContent.contentTypeResultsXML)
               || contentType.equals(WebContent.contentTypeXML);
    }
}