org.joseki.http.AcceptList Maven / Gradle / Ivy
/*
* (c) Copyright 2004, 2005, 2006, 2007, 2008, 2009 Hewlett-Packard Development Company, LP
* All rights reserved.
* [See end of file]
*/
package org.joseki.http;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import org.joseki.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** A class to handle a list of accept types (AcceptRanges)
*
* @author Andy Seaborne
* @version $Id: AcceptList.java,v 1.13 2009/10/12 17:26:04 andy_seaborne Exp $
*/
public class AcceptList implements Iterable
{
// Documentation at end
private static Logger log = LoggerFactory.getLogger(AcceptList.class) ;
List list ;
/**
* Create a list of accept items from the give strings.
* @param acceptStrings
*/
public AcceptList(List acceptStrings)
{
list = new ArrayList(acceptStrings) ;
}
/**
* Create a list of accept items from the give strings.
* @param acceptStrings
*/
public AcceptList(String... acceptStrings)
{
list = new ArrayList() ;
for ( int i = 0 ; i < acceptStrings.length ; i++ )
list.add(new AcceptItem(acceptStrings[i])) ;
}
/**
* Parse an HTTP Accept (or etc) header string.
* @param headerString
*/
public AcceptList(String headerString)
{
try {
list = stringToAcceptList(headerString) ;
} catch (Exception ex)
{
log.warn("Unrecognized accept string (ignored): "+headerString) ;
list = new ArrayList() ;
}
}
public boolean accepts(AcceptItem aItem)
{
return match(aItem) != null ;
}
public AcceptItem match(AcceptItem aItem)
{
for ( AcceptItem acceptItem : list )
{
//System.out.println("Check: "+i+" accepts "+aItem) ;
if ( acceptItem.accepts(aItem) )
{
// Return the more grounded term
// E.g. i = text/plain ; aItem = text/*
if ( aItem.moreGroundedThan(acceptItem) )
acceptItem = new AcceptItem(aItem, acceptItem.q) ;
return acceptItem ;
}
}
return null ;
}
/** Find the best thing in offer list with the proposal
*
* @param proposalList Client list of possibilities
* @param offerList Server list of possibilities
* @return AcceptItem
*/
static public AcceptItem match(AcceptList proposalList, AcceptList offerList)
{
// TODO Need to find the best match, not the first offer match.
// Find every offer match, choose the highest q factor
AcceptItem choice = null ;
for ( AcceptItem offer : offerList )
{
AcceptItem m = proposalList.match(offer) ; // XXX
if ( m != null )
{
if ( choice != null && choice.q >= m.q )
continue ;
choice = m ;
}
}
return choice ;
}
public AcceptItem first()
{
if ( list != null && list.size() > 0 )
return list.get(0) ;
return null ;
}
//Java6: @Override
public Iterator iterator()
{ return list.iterator() ; }
// Sort - the leftmost element (lowest index) will be the preferred accept type.
private static class AcceptTypeCompare implements Comparator
{
public int compare(AcceptItem mType1, AcceptItem mType2)
{
int r = Double.compare(mType1.q, mType2.q) ;
if ( r == 0 )
r = subCompare(mType1.getAcceptType(), mType2.getAcceptType()) ;
if ( r == 0 )
r = subCompare(mType1.getAcceptType(), mType2.getAcceptType()) ;
if ( r == 0 )
{
// This reverses the input order so that the rightmost elements is the
// greatest and hence is the first mentioned in the accept range.
if ( mType1.posn < mType2.posn )
r = +1 ;
if ( mType1.posn > mType2.posn )
r = -1 ;
}
// The most significant sorts to the first in a list.
r = -r ;
return r ;
}
public int subCompare(String a, String b)
{
if ( a == null )
return 1 ;
if ( b == null )
return -1 ;
if ( a.equals("*") && b.equals("*") )
return 0 ;
if ( a.equals("*") )
return -1 ;
if ( b.equals("*") )
return 1 ;
return 0 ;
}
}
// Utilities
/** Returns a list of headers, sorted so that the most significant is first */
static List stringToAcceptList(String s)
{
//s = s.trim() ;
List l = new ArrayList() ;
if ( s == null )
return l ;
String[] x = StringUtils.split(s, ",") ;
for ( int i = 0 ; i < x.length ; i++ )
{
if ( x[i].equals(""))
continue ;
AcceptItem mType = new AcceptItem(x[i]) ;
mType.posn = i ;
l.add(mType) ;
}
Collections.sort(l, new AcceptTypeCompare()) ;
return l ;
}
public String toHeaderString()
{
if ( list.size() == 0)
return "" ;
String tmp = "" ;
boolean first = true ;
for ( AcceptItem item : list )
{
if ( ! first )
tmp = tmp +"," ;
tmp = tmp + item.toHeaderString() ;
first = false ;
}
return tmp ;
}
/** Debug form */
@Override
public String toString() { return acceptListToString(list) ; }
static String acceptListToString(List x)
{
if ( x.size() == 0)
return "(empty)" ;
String tmp = "" ;
boolean first = true ;
for ( AcceptItem acceptItem : x )
{
if ( ! first )
tmp = tmp +" " ;
acceptItem.toString();
tmp = tmp + acceptItem ;
first = false ;
}
return tmp ;
}
// static List multiCombineMT(List list1, List list2)
// {
// List r = new ArrayList() ;
// r.add(list1) ;
// r.add(list2) ;
// Collections.sort(r, new AcceptTypeCompare()) ;
// return r ;
// }
}
// RFC 2068(HTTP 1.1) defines the format:
// media-type = type "/" subtype *( ";" parameter )
// type = token
// subtype = token
//
// Parameters may follow the type/subtype in the form of attribute/value pairs.
//
// parameter = attribute "=" value
// attribute = token
// value = token | quoted-string
// Accept = "Accept" ":"
// #( media-range [ accept-params ] )
//
//media-range = ( "*/*"
// | ( type "/" "*" )
// | ( type "/" subtype )
// ) *( ";" parameter )
//
//accept-params = ";" "q" "=" qvalue *( accept-extension )
//
//accept-extension = ";" token [ "=" ( token | quoted-string ) ]
//
// Accept-Charset = "Accept-Charset" ":"
// 1#( charset [ ";" "q" "=" qvalue ] )
// Examples:
// -- Firefox 1.0
// Accept = text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
// Accept-Language = en-us,en;q=0.5
// Accept-Encoding = gzip,deflate
// Accept-Charset = ISO-8859-1,utf-8;q=0.7,*;q=0.7
// -- IE 6
// Accept = image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*
// Accept-Language = en-gb
// Accept-Encoding = gzip, deflate
/*
* (c) Copyright 2004, 2005, 2006, 2007, 2008, 2009 Hewlett-Packard Development Company, LP
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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