From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Sun, 13 Dec 2009 20:14:31 +0000 (+0100)
Subject: Added a utility class for parsing Accept* headers.
X-Git-Url: http://git.dolda2000.com/gitweb/?a=commitdiff_plain;h=15443216a029804091da8aa6fe87427f675e9e64;p=jsvc.git

Added a utility class for parsing Accept* headers.
---

diff --git a/src/dolda/jsvc/util/AcceptMap.java b/src/dolda/jsvc/util/AcceptMap.java
new file mode 100644
index 0000000..b74cace
--- /dev/null
+++ b/src/dolda/jsvc/util/AcceptMap.java
@@ -0,0 +1,157 @@
+package dolda.jsvc.util;
+
+import java.util.*;
+import java.io.*;
+
+public class AcceptMap implements Iterable<AcceptMap.Entry> {
+    private static final Entry[] typehint = new Entry[0];
+    private final Entry[] list;
+    private static final Comparator<Entry> lcmp = new Comparator<Entry>() {
+	public int compare(Entry a, Entry b) {
+	    if(a.q > b.q)
+		return(-1);
+	    else if(a.q < b.q)
+		return(1);
+	    return(0);
+	}
+    };
+    
+    public static class Entry {
+	public String type;
+	public double q = 1.0;
+	public Map<String, String> pars = new HashMap<String, String>();
+    }
+    
+    private AcceptMap(Entry[] list) {
+	this.list = list;
+    }
+    
+    private static String token(PushbackReader in) throws IOException {
+	Misc.eatws(in);
+	StringBuilder buf = new StringBuilder();
+	while(true) {
+	    int c = in.read();
+	    if((c < 0) || Character.isWhitespace((char)c) || (",;=:\\\"?".indexOf((char)c) >= 0)) {
+		if(c >= 0)
+		    in.unread(c);
+		if(buf.length() == 0)
+		    return(null);
+		return(buf.toString());
+	    } else {
+		buf.append((char)c);
+	    }
+	}
+    }
+
+    public static AcceptMap parse(Reader in) throws IOException {
+	PushbackReader pin = new PushbackReader(in);
+	List<Entry> lbuf = new LinkedList<Entry>();
+	List<Entry> ebuf = new LinkedList<Entry>();
+	while(true) {
+	    Entry e = new Entry();
+	    if((e.type = token(pin)) == null)
+		throw(new Http.EncodingException("Illegal format for Accept* header (expected type)"));
+	    ebuf.add(e);
+	    Misc.eatws(pin);
+	    int sep = pin.read();
+	    if(sep < 0) {
+		lbuf.addAll(ebuf);
+		break;
+	    } else if(sep == ';') {
+		String st = "tp";
+		boolean flush = false;
+		boolean end = false;
+		while(true) {
+		    String key = Http.tokenunquote(pin);
+		    Misc.eatws(pin);
+		    if(pin.read() != '=')
+			throw(new Http.EncodingException("Illegal format for Accept* header (expected `=' in parameter)"));
+		    String val = Http.tokenunquote(pin);
+		    Misc.eatws(pin);
+		    int psep = pin.read();
+		    if(st == "tp") {
+			if(key.equals("q")) {
+			    double q;
+			    try {
+				q = Double.parseDouble(val);
+			    } catch(NumberFormatException exc) {
+				throw(new Http.EncodingException(exc.getMessage()));
+			    }
+			    for(Entry e2 : ebuf)
+				e2.q = q;
+			    flush = true;
+			    st = "ap";
+			} else if(st == "ap") {
+			    e.pars.put(key, val);
+			}
+		    } else {
+			/* No known accept-params */
+		    }
+		    if(psep < 0) {
+			end = true;
+			flush = true;
+			break;
+		    } else if(psep == ';') {
+		    } else if(psep == ',') {
+			break;
+		    } else {
+			throw(new Http.EncodingException("Illegal format for Accept* header (expected `;', `,' or end of parameters)"));
+		    }
+		}
+		if(flush) {
+		    lbuf.addAll(ebuf);
+		    ebuf = new LinkedList<Entry>();
+		}
+		if(end)
+		    break;
+	    } else if(sep == ',') {
+	    } else {
+		throw(new Http.EncodingException("Illegal format for Accept* header (expected `;', `,' or end of list)"));
+	    }
+	}
+	Entry[] list = lbuf.toArray(typehint);
+	Arrays.sort(list, lcmp);
+	return(new AcceptMap(list));
+    }
+    
+    public static AcceptMap parse(String input) {
+	try {
+	    return(parse(new StringReader(input)));
+	} catch(IOException e) {
+	    throw(new Error(e));
+	}
+    }
+
+    public Iterator<Entry> iterator() {
+	return(new Iterator<Entry>() {
+		private int i = 0;
+		
+		public Entry next() {
+		    return(list[i++]);
+		}
+		
+		public boolean hasNext() {
+		    return(i < list.length);
+		}
+		
+		public void remove() {
+		    throw(new UnsupportedOperationException());
+		}
+	    });
+    }
+    
+    public Entry accepts(String type) {
+	for(Entry e : list) {
+	    if(e.type.equals(type))
+		return(e);
+	}
+	return(null);
+    }
+    
+    public String toString() {
+	StringBuilder buf = new StringBuilder();
+	for(Entry e : list)
+	    buf.append(String.format("%s %f %s\n", e.type, e.q, e.pars));
+	return(buf.toString());
+    }
+}