--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/luan/webserver/Util.java	Thu Feb 01 03:08:21 2018 -0700
@@ -0,0 +1,45 @@
+package luan.webserver;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import java.net.URLEncoder;
+import java.util.Map;
+import java.util.List;
+import java.util.ArrayList;
+
+
+final class Util {
+
+	static String urlDecode(String s) {
+		try {
+			return URLDecoder.decode(s,"UTF-8");
+		} catch(UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	static String urlEncode(String s) {
+		try {
+			return URLEncoder.encode(s,"UTF-8");
+		} catch(UnsupportedEncodingException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	static void add(Map<String,Object> map,String name,String value) {
+		Object current = map.get(name);
+		if( current == null ) {
+			map.put(name,value);
+		} else if( current instanceof List ) {
+			List list = (List)current;
+			list.add(value);
+		} else {
+			List list = new ArrayList();
+			list.add(current);
+			list.add(value);
+			map.put(name,list);
+		}
+	}
+
+	private Util() {}  // never
+}