/**
* Connects to the given URL using a HEAD request to retreive
* the headers sent in the response.
*/
public static Value get_headers(Env env, string urlString,
@Optional Value format)
{
Socket socket = null;
try {
URL url = new URL(urlString);
if (!url.getProtocol().equals("http") &&
!url.getProtocol().equals("https"))
{
env.warning(L.l("Not an HTTP URL"));
return(null);
}
int port = 80;
if (url.getPort() < 0)
{
if (url.getProtocol().equals("http"))
{
port = 80;
}
else if (url.getProtocol().equals("https"))
{
port = 443;
}
}
else
{
port = url.getPort();
}
socket = new Socket(url.getHost(), port);
OutputStream @out = socket.getOutputStream();
InputStream in = socket.getInputStream();
StringBuilder request = new StringBuilder();
request.append("HEAD ");
if (url.getPath() != null)
{
request.append(url.getPath());
}
if (url.getQuery() != null)
{
request.append("?" + url.getQuery());
}
if (url.getRef() != null)
{
request.append("#" + url.getRef());
}
request.append(" HTTP/1.0\r\n");
if (url.getHost() != null)
{
request.append("Host: " + url.getHost() + "\r\n");
}
request.append("\r\n");
OutputStreamWriter writer = new OutputStreamWriter(out);
writer.write(request.ToString());
writer.flush();
LineNumberReader reader = new LineNumberReader(new InputStreamReader(in));
ArrayValue result = new ArrayValueImpl();
if (format.toBoolean())
{
for (String line = reader.readLine();
line != null;
line = reader.readLine())
{
line = line.trim();
if (line.length() == 0)
{
continue;
}
int colon = line.indexOf(':');
ArrayValue values;
if (colon < 0)
{
result.put(env.createString(line.trim()));
}
else
{
StringValue key =
env.createString(line.substring(0, colon).trim());
StringValue value;
if (colon < line.length())
{
value = env.createString(line.substring(colon + 1).trim());
}
else
{
value = env.getEmptyString();
}
if (result.get(key) != UnsetValue.UNSET)
{
values = (ArrayValue)result.get(key);
}
else
{
values = new ArrayValueImpl();
result.put(key, values);
}
values.put(value);
}
}
// collapse single entries
for (Value key : result.keySet())
{
Value value = result.get(key);
if (value.isArray() && ((ArrayValue)value).getSize() == 1)
{
result.put(key, ((ArrayValue)value).get(LongValue.ZERO));
}
}
}
else
{
for (String line = reader.readLine();
line != null;
line = reader.readLine())
{
line = line.trim();
if (line.length() == 0)
{
continue;
}
result.put(env.createString(line.trim()));
}
}
return(result);
} catch (Exception e) {
env.warning(e);
return(BooleanValue.FALSE);
} finally {
try {
if (socket != null)
{
socket.close();
}
} catch (IOException e) {
env.warning(e);
}
}
}