1  
   2  import java.io.IOException;
   3  import java.io.InputStream;
   4  import java.nio.ByteBuffer;
   5  import java.nio.charset.Charset;
   6  import java.util.HashMap;
   7  
   8  /**
   9   * SCGI connector.<br>
  10   * Version: 1.0<br>
  11   * Home page: http://snippets.dzone.com/posts/show/4304
  12   */
  13  public class SCGI {
  14    public static class SCGIException extends IOException {
  15      private static final long serialVersionUID = 1L;
  16  
  17      public SCGIException(String message) {
  18        super(message);
  19      }
  20    }
  21  
  22    /** Used to decode the headers. */
  23    public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
  24  
  25    /**
  26     * Read the <a href="http://python.ca/scgi/protocol.txt">SCGI</a> request headers.<br>
  27     * After the headers had been loaded,
  28     * you can read the body of the request manually from the same {@code input} stream:<pre>
  29     *   // Load the SCGI headers.
  30     *   Socket clientSocket = socket.accept();
  31     *   BufferedInputStream bis = new BufferedInputStream(clientSocket.getInputStream(), 4096);
  32     *   HashMap<String, String> env = SCGI.parse(bis);
  33     *   // Read the body of the request.
  34     *   bis.read(new byte[Integer.parseInt(env.get("CONTENT_LENGTH"))]);
  35     * </pre>
  36     * @param input an efficient (buffered) input stream.
  37     * @return strings passed via the SCGI request.
  38     */
  39    public static HashMap parse(InputStream input) throws IOException {
  40      StringBuilder lengthString = new StringBuilder(12);
  41      String headers = "";
  42      for (;;) {
  43        char ch = (char) input.read();
  44        if (ch >= '0' && ch <= '9') {
  45          lengthString.append(ch);
  46        } else if (ch == ':') {
  47          int length = Integer.parseInt(lengthString.toString());
  48          byte[] headersBuf = new byte[length];
  49          int read = input.read(headersBuf);
  50          if (read != headersBuf.length)
  51            throw new SCGIException("Couldn't read all the headers (" + length + ").");
  52          headers = ISO_8859_1.decode(ByteBuffer.wrap(headersBuf)).toString();
  53          if (input.read() != ',') throw new SCGIException("Wrong SCGI header length: " + lengthString);
  54          break;
  55        } else {
  56          lengthString.append(ch);
  57          throw new SCGIException("Wrong SCGI header length: " + lengthString);
  58        }
  59      }
  60      HashMap env = new HashMap();
  61      while (headers.length() != 0) {
  62        int sep1 = headers.indexOf(0);
  63        int sep2 = headers.indexOf(0, sep1 + 1);
  64        env.put(headers.substring(0, sep1), headers.substring(sep1 + 1, sep2));
  65        headers = headers.substring(sep2 + 1);
  66      }
  67      return env;
  68    }
  69  }