Many bugfixes and improvements

src/zutil/parser/BEncodedParser.java

@@ -0,0 +1,101 @@
+package zutil.parser;
+
+import zutil.parser.DataNode.DataType;
+
+/**
+ * http://wiki.theory.org/BitTorrentSpecification
+ * @author Ziver
+ *
+ */
+public class BEncodedParser {
+
+	/**
+	 * Returns the representation of the data in the BEncoded string
+	 * 
+	 * @param data The data to be decoded
+	 * @return
+	 */
+	public static DataNode parse(String data){
+		return decode_BEncoded(new StringBuffer(data));
+	}
+
+	/**
+	 * Returns the representation of the data in the BEncoded string
+	 * 
+	 * @param data The data to be decoded
+	 * @param index The index in data to start from
+	 * @return
+	 */
+	private static DataNode decode_BEncoded(StringBuffer data){
+		String tmp;
+		char c = ' ';
+
+		switch (data.charAt(0)) {
+		/**
+		 * Integers are prefixed with an i and terminated by an e. For
+		 * example, 123 would bEcode to i123e, -3272002 would bEncode to
+		 * i-3272002e.
+		 */
+		case 'i':
+			//System.out.println("Found Integer at "+index);
+			data.deleteCharAt(0);
+			tmp = data.substring(0, data.indexOf("e"));
+			data.delete(0, tmp.length() + 1);
+			//System.out.println(tmp);
+			return new DataNode( new Long(tmp));
+		/**
+		 * Lists are prefixed with a l and terminated by an e. The list
+		 * should contain a series of bEncoded elements. For example, the
+		 * list of strings ["Monduna", "Bit", "Torrents"] would bEncode to
+		 * l7:Monduna3:Bit8:Torrentse. The list [1, "Monduna", 3, ["Sub", "List"]]
+		 * would bEncode to li1e7:Mondunai3el3:Sub4:Listee
+		 */
+		case 'l':
+			//System.out.println("Found List at "+index);
+			data.deleteCharAt(0);
+			DataNode list = new DataNode( DataType.List );
+			c = data.charAt(0);
+			while(c != 'e'){
+				list.add( decode_BEncoded(data) );
+				c = data.charAt(0);
+			}
+			data.deleteCharAt(0);
+			//MultiPrintStream.out.dump(list);
+			if(list.size() == 1) return list.get(0);
+			else return list;
+		/**
+		 * Dictionaries are prefixed with a d and terminated by an e. They
+		 * are similar to list, except that items are in key value pairs. The
+		 * dictionary {"key":"value", "Monduna":"com", "bit":"Torrents", "number":7}
+		 * would bEncode to d3:key5:value7:Monduna3:com3:bit:8:Torrents6:numberi7ee
+		 */
+		case 'd':
+			//System.out.println("Found Dictionary at "+index);
+			data.deleteCharAt(0);
+			DataNode map = new DataNode( DataType.Map );
+			c = data.charAt(0);
+			while(c != 'e'){
+				DataNode tmp2 = decode_BEncoded(data);
+				map.set(tmp2.getString(), decode_BEncoded(data));
+				c = data.charAt(0);
+			}
+			data.deleteCharAt(0);
+			//MultiPrintStream.out.dump(map);
+			return map;
+		/**
+		 * Strings are prefixed with their length followed by a colon.
+		 * For example, "Monduna" would bEncode to 7:Monduna and "BitTorrents"
+		 * would bEncode to 11:BitTorrents.
+		 */
+		default:
+			//System.out.println("Found String at "+index);
+			tmp = data.substring(0, data.indexOf(":"));
+			int length = Integer.parseInt(tmp);
+			data.delete(0, tmp.length()+1);
+			String ret = data.substring(0, length);
+			data.delete(0, length);
+			//System.out.println(data.substring(i, i+length));
+			return new DataNode( ret );
+		}
+	}
+}