/*
* 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.io.PrintWriter ;
import java.util.concurrent.atomic.AtomicLong ;
import javax.servlet.http.HttpServlet ;
import javax.servlet.http.HttpServletRequest ;
import javax.servlet.http.HttpServletResponse ;
import org.apache.jena.atlas.lib.StrUtils ;
import org.apache.jena.fuseki.Fuseki ;
import org.apache.jena.fuseki.HttpNames ;
import org.apache.jena.web.HttpSC ;
import org.slf4j.Logger ;
/**
* An abstract HTTP Servlet. Contains implementation methods for setting the request status in a HTTP Action,
* and a mechanism to allocate unique ID's to new requests.
*/
public abstract class ServletBase extends HttpServlet
{
protected static final Logger log = Fuseki.requestLog ;
public final boolean verboseLogging = Fuseki.verboseLogging ;
private static AtomicLong requestIdAlloc = new AtomicLong(0) ;
protected ServletBase() { }
/**
* Helper method which gets a unique request ID and appends it as a header to the response
* @param request HTTP Request
* @param response HTTP Response
* @return Request ID
*/
protected long allocRequestId(HttpServletRequest request, HttpServletResponse response) {
long id = requestIdAlloc.incrementAndGet();
addRequestId(response, id);
return id;
}
/**
* Helper method for attaching a request ID to a response as a header
* @param response Response
* @param id Request ID
*/
protected void addRequestId(HttpServletResponse response, long id) {
response.addHeader("Fuseki-Request-ID", Long.toString(id));
}
protected void responseSendError(HttpServletResponse response, int statusCode, String message)
{
try { response.sendError(statusCode, message) ; }
catch (IOException ex) { errorOccurred(ex) ; }
catch (IllegalStateException ex) { }
}
protected void responseSendError(HttpServletResponse response, int statusCode)
{
try { response.sendError(statusCode) ; }
catch (IOException ex) { errorOccurred(ex) ; }
}
/**
* Returns the HTTP request URL, appended with any additional URL parameters used.
*
* @param request HTTP request
* @return complete request URL
*/
protected static String wholeRequestURL(HttpServletRequest request)
{
StringBuffer sb = request.getRequestURL() ;
String queryString = request.getQueryString() ;
if ( queryString != null )
{
sb.append("?") ;
sb.append(queryString) ;
}
return sb.toString() ;
}
protected static void successNoContent(HttpAction action)
{
success(action, HttpSC.NO_CONTENT_204);
}
protected static void success(HttpAction action)
{
success(action, HttpSC.OK_200);
}
protected static void successCreated(HttpAction action)
{
success(action, HttpSC.CREATED_201);
}
// When 404 is no big deal e.g. HEAD
protected static void successNotFound(HttpAction action)
{
success(action, HttpSC.NOT_FOUND_404) ;
}
//
protected static void success(HttpAction action, int httpStatusCode)
{
action.response.setStatus(httpStatusCode);
}
protected static void successPage(HttpAction action, String message)
{
try {
action.response.setContentType("text/html");
action.response.setStatus(HttpSC.OK_200);
PrintWriter out = action.response.getWriter() ;
out.println("<html>") ;
out.println("<head>") ;
out.println("</head>") ;
out.println("<body>") ;
out.println("<h1>Success</h1>");
if ( message != null )
{
out.println("<p>") ;
out.println(message) ;
out.println("</p>") ;
}
out.println("</body>") ;
out.println("</html>") ;
out.flush() ;
} catch (IOException ex) { errorOccurred(ex) ; }
}
protected static void warning(String string)
{
log.warn(string) ;
}
protected static void warning(String string, Throwable thorwable)
{
log.warn(string, thorwable) ;
}
protected static void errorBadRequest(String string)
{
error(HttpSC.BAD_REQUEST_400, string) ;
}
protected static void errorNotFound(String string)
{
error(HttpSC.NOT_FOUND_404, string) ;
}
protected static void errorNotImplemented(String msg)
{
error(HttpSC.NOT_IMPLEMENTED_501, msg) ;
}
protected static void errorMethodNotAllowed(String method)
{
error(HttpSC.METHOD_NOT_ALLOWED_405, "HTTP method not allowed: "+method) ;
}
protected static void errorForbidden(String msg)
{
if ( msg != null )
error(HttpSC.FORBIDDEN_403, msg) ;
else
error(HttpSC.FORBIDDEN_403, "Forbidden") ;
}
protected static void error(int statusCode)
{
throw new ActionErrorException(null, null, statusCode) ;
}
protected static void error(int statusCode, String string)
{
throw new ActionErrorException(null, string, statusCode) ;
}
protected static void errorOccurred(String message)
{
errorOccurred(message, null) ;
}
protected static void errorOccurred(Throwable ex)
{
errorOccurred(null, ex) ;
}
protected static void errorOccurred(String message, Throwable ex)
{
throw new ActionErrorException(ex, message, HttpSC.INTERNAL_SERVER_ERROR_500) ;
}
protected static String formatForLog(String string)
{
string = string.replace('\n', ' ') ;
string = string.replace('\r', ' ') ;
return string ;
}
static String varyHeaderSetting =
StrUtils.strjoin(",",
HttpNames.hAccept,
HttpNames.hAcceptEncoding,
HttpNames.hAcceptCharset ) ;
public static void setVaryHeader(HttpServletResponse httpResponse)
{
httpResponse.setHeader(HttpNames.hVary, varyHeaderSetting) ;
}
public static void setCommonHeadersForOptions(HttpServletResponse httpResponse)
{
httpResponse.setHeader(HttpNames.hAccessControlAllowHeaders, "X-Requested-With, Content-Type, Authorization") ;
setCommonHeaders(httpResponse) ;
}
public static void setCommonHeaders(HttpServletResponse httpResponse)
{
httpResponse.setHeader(HttpNames.hAccessControlAllowOrigin, "*") ;
httpResponse.setHeader(HttpNames.hServer, Fuseki.serverHttpName) ;
}
}