package org.scribe.utils;

import java.io.*;

import java.net.*;

import java.util.*;

import org.scribe.exceptions.*;

public class URLUtils

{

private static final String EMPTY_STRING = "";

private static final String UTF_8 = "UTF-8";

private static final char PAIR_SEPARATOR = '=';

private static final char PARAM_SEPARATOR = '&';

private static final String ERROR_MSG = String.format("Cannot find specified encoding: %s", UTF_8);

public static String formURLEncodeMap(Map<String, List<String>> map)

{

Preconditions.checkNotNull(map, "Cannot url-encode a null object");

return (map.size() <= 0) ? EMPTY_STRING : doFormUrlEncode(map);

}

private static String doFormUrlEncode(Map<String, List<String>> map)

{

StringBuffer encodedString = new StringBuffer();

for (String key : map.keySet())

{

for(String value: map.get(key))

{

encodedString.append(percentEncode(key)).append(PAIR_SEPARATOR).append(percentEncode(value)).append(PARAM_SEPARATOR);

}

}

return removeTrailingSeparator(encodedString);

}

private static String removeTrailingSeparator(StringBuffer buffer)

{

return buffer.toString().substring(0, buffer.length() - 1);

}

public static String percentEncode(String string)

{

Preconditions.checkNotNull(string, "Cannot encode null string");

try

{

return URLEncoder.encode(string, UTF_8);

} catch (UnsupportedEncodingException uee)

{

throw new OAuthException(ERROR_MSG, uee);

}

}

public static String percentDecode(String string)

{

Preconditions.checkNotNull(string, "Cannot decode null string");

try

{

return URLDecoder.decode(string, UTF_8);

} catch (UnsupportedEncodingException uee)

{

throw new OAuthException(ERROR_MSG, uee);

}

}

}