//******************************************************************************
//
// File: HttpResponse.java
// Package: edu.rit.http
// Unit: Class edu.rit.http.HttpResponse
//
// This Java source file is copyright (C) 2006 by Alan Kaminsky. All rights
// reserved. For further information, contact the author, Alan Kaminsky, at
// ark@cs.rit.edu.
//
// This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
// software; you can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// PJ is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
// A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// A copy of the GNU General Public License is provided in the file gpl.txt. You
// may also obtain a copy of the GNU General Public License on the World Wide
// Web at http://www.gnu.org/licenses/gpl.html.
//
//******************************************************************************
package edu.rit.http;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;
// For unit test main program
// import java.net.InetSocketAddress;
// import java.net.ServerSocket;
/**
* Class HttpResponse encapsulates an HTTP response returned to a web browser.
*
* Only HTTP/1.0 responses are supported. This means that only one HTTP response
* message can be sent over the connection to the web browser; the connection is
* closed after sending the HTTP response message.
*
* To send an HTTP response message:
*
* -
* Create an instance of class HttpResponse, giving the socket object
* representing the open connection to the web browser.
*
* -
* Call methods to set the status code and headers as necessary.
*
* -
* Call the getPrintWriter() method, and write the entity body to the
* print writer that is returned.
*
* -
* Call the close() method.
*
*
* @author Alan Kaminsky
* @version 29-Jul-2010
*/
public class HttpResponse
{
// Exported enumerations.
/**
* Enumeration HttpResponse.Status enumerates the status codes for an HTTP
* response message.
*
* @author Alan Kaminsky
* @version 10-Oct-2006
*/
public static enum Status
{
/**
* The request has succeeded.
*/
STATUS_200_OK ("200 OK"),
/**
* The request has been fulfilled and resulted in a new resource being
* created.
*/
STATUS_201_CREATED ("201 Created"),
/**
* The request has been accepted for processing, but the processing has
* not been completed.
*/
STATUS_202_ACCEPTED ("202 Accepted"),
/**
* The server has fulfilled the request but there is no new information
* to send back.
*/
STATUS_204_NO_CONTENT ("204 No content"),
/**
* The requested resource has been assigned a new permanent URL and any
* future references to this resource should be done using that URL.
*/
STATUS_301_MOVED_PERMANENTLY ("301 Moved Permanently"),
/**
* The requested resource resides temporarily under a different URL.
*/
STATUS_302_MOVED_TEMPORARILY ("302 Moved Temporarily"),
/**
* If the client has performed a conditional GET request and access is
* allowed, but the document has not been modified since the date and
* time specified in the If-Modified-Since field, the server must
* respond with this status code and not send an Entity-Body to the
* client.
*/
STATUS_304_NOT_MODIFIED ("304 Not Modified"),
/**
* The request could not be understood by the server due to malformed
* syntax.
*/
STATUS_400_BAD_REQUEST ("400 Bad Request"),
/**
* The request requires user authentication.
*/
STATUS_401_UNAUTHORIZED ("401 Unauthorized"),
/**
* The server understood the request, but is refusing to fulfill it.
*/
STATUS_403_FORBIDDEN ("403 Forbidden"),
/**
* The server has not found anything matching the Request-URI.
*/
STATUS_404_NOT_FOUND ("404 Not Found"),
/**
* The server encountered an unexpected condition which prevented it
* from fulfilling the request.
*/
STATUS_500_INTERNAL_SERVER_ERROR ("500 Internal Server Error"),
/**
* The server does not support the functionality required to fulfill the
* request.
*/
STATUS_501_NOT_IMPLEMENTED ("501 Not Implemented"),
/**
* The server, while acting as a gateway or proxy, received an invalid
* response from the upstream server it accessed in attempting to
* fulfill the request.
*/
STATUS_502_BAD_GATEWAY ("502 Bad Gateway"),
/**
* The server is currently unable to handle the request due to a
* temporary overloading or maintenance of the server.
*/
STATUS_503_SERVICE_UNAVAILABLE ("503 Service Unavailable");
private final String stringForm;
/**
* Construct a new Status value.
*
* @param stringForm String form.
*/
Status
(String stringForm)
{
this.stringForm = stringForm;
}
/**
* Returns a string version of this Status value.
*
* @return String version.
*/
public String toString()
{
return stringForm;
}
}
// Hidden data members.
private Socket mySocket;
private Status myStatusCode = Status.STATUS_200_OK;
private String myContentType = "text/html";
private Charset myCharset = Charset.defaultCharset();
private Map myHeaderMap = new HashMap();
private PrintWriter myPrintWriter;
// Exported constructors.
/**
* Construct a new HTTP response. The response is written to the output
* stream of the given socket.
*
* @param theSocket Socket.
*
* @exception NullPointerException
* (unchecked exception) Thrown if theSocket is null.
*/
public HttpResponse
(Socket theSocket)
{
if (theSocket == null)
{
throw new NullPointerException
("HttpResponse(): theSocket is null");
}
mySocket = theSocket;
recordContentType();
}
// Exported operations.
/**
* Set this HTTP response's status code. If not set, the default status code
* is STATUS_200_OK.
*
* @param theStatusCode Status code.
*
* @exception NullPointerException
* (unchecked exception) Thrown if theStatusCode is null.
* @exception IllegalStateException
* (unchecked exception) Thrown if the HTTP response headers have
* already been written to the socket output stream.
*/
public void setStatusCode
(Status theStatusCode)
{
if (theStatusCode == null)
{
throw new NullPointerException
("HttpResponse.setStatusCode(): theStatusCode is null");
}
if (myPrintWriter != null)
{
throw new IllegalStateException
("HttpResponse.setStatusCode(): Headers already written");
}
myStatusCode = theStatusCode;
}
/**
* Set this HTTP response's content type. If not set, the default content
* type is "text/html".
*
* @param theContentType Content type.
*
* @exception NullPointerException
* (unchecked exception) Thrown if theContentType is null.
* @exception IllegalArgumentException
* (unchecked exception) Thrown if theContentType is zero
* length.
* @exception IllegalStateException
* (unchecked exception) Thrown if the HTTP response headers have
* already been written to the socket output stream.
*/
public void setContentType
(String theContentType)
{
if (theContentType == null)
{
throw new NullPointerException
("HttpResponse.setContentType(): theContentType is null");
}
if (theContentType.length() == 0)
{
throw new IllegalArgumentException
("HttpResponse.setContentType(): theContentType is zero length");
}
if (myPrintWriter != null)
{
throw new IllegalStateException
("HttpResponse.setContentType(): Headers already written");
}
myContentType = theContentType;
recordContentType();
}
/**
* Set this HTTP response's character set. If not set, the default character
* set is the platform default character set.
*
* @param theCharset Character set.
*
* @exception NullPointerException
* (unchecked exception) Thrown if theCharset is null.
* @exception IllegalStateException
* (unchecked exception) Thrown if the HTTP response headers have
* already been written to the socket output stream.
*/
public void setCharset
(Charset theCharset)
{
if (theCharset == null)
{
throw new NullPointerException
("HttpResponse.setCharset(): theCharset is null");
}
if (myPrintWriter != null)
{
throw new IllegalStateException
("HttpResponse.setCharset(): Headers already written");
}
myCharset = theCharset;
recordContentType();
}
/**
* Set this HTTP response's content length. If not set, the default is to
* omit the Content-Length header; closing this HTTP response marks the end
* of the entity body.
*
* @param theContentLength Content length.
*
* @exception IllegalArgumentException
* (unchecked exception) Thrown if theContentLength is less
* than 0.
* @exception IllegalStateException
* (unchecked exception) Thrown if the HTTP response headers have
* already been written to the socket output stream.
*/
public void setContentLength
(int theContentLength)
{
if (theContentLength < 0)
{
throw new IllegalArgumentException
("HttpResponse.setContentLength(): theContentLength < 0");
}
if (myPrintWriter != null)
{
throw new IllegalStateException
("HttpResponse.setContentLength(): Headers already written");
}
myHeaderMap.put ("Content-Length", ""+theContentLength);
}
/**
* Set the given header in this HTTP response.
*
* @param theHeaderName Header name.
* @param theHeaderValue Header value.
*
* @exception NullPointerException
* (unchecked exception) Thrown if theHeaderName or
* theHeaderValue is null.
* @exception IllegalArgumentException
* (unchecked exception) Thrown if theHeaderName or
* theHeaderValue is zero length.
* @exception IllegalStateException
* (unchecked exception) Thrown if the HTTP response headers have
* already been written to the socket output stream.
*/
public void setHeader
(String theHeaderName,
String theHeaderValue)
{
if (theHeaderName == null)
{
throw new NullPointerException
("HttpResponse.setHeader(): theHeaderName is null");
}
if (theHeaderName.length() == 0)
{
throw new IllegalArgumentException
("HttpResponse.setHeader(): theHeaderName is zero length");
}
if (theHeaderValue == null)
{
throw new NullPointerException
("HttpResponse.setHeader(): theHeaderValue is null");
}
if (theHeaderValue.length() == 0)
{
throw new IllegalArgumentException
("HttpResponse.setHeader(): theHeaderValue is zero length");
}
if (myPrintWriter != null)
{
throw new IllegalStateException
("HttpResponse.setHeader(): Headers already written");
}
myHeaderMap.put (theHeaderName, theHeaderValue);
}
/**
* Obtain the print writer for writing the entity body to this HTTP
* response. As a side effect, the HTTP response headers are written to the
* socket output stream.
*
* @return Print writer.
*
* @exception IOException
* Thrown if an I/O error occurred.
*/
public PrintWriter getPrintWriter()
throws IOException
{
return writeHeaders();
}
/**
* Close this HTTP response. If necessary, the HTTP response headers are
* written to the socket output stream.
*
* @exception IOException
* Thrown if an I/O error occurred.
*/
public void close()
throws IOException
{
writeHeaders();
myPrintWriter.close();
mySocket.close();
}
// Hidden operations.
/**
* Record the Content-Type header.
*/
private void recordContentType()
{
myHeaderMap.put
("Content-Type",
myContentType + "; charset=" + myCharset);
}
/**
* Write the headers to the socket output stream if not already written, and
* return the print writer for writing to the socket output stream.
*
* @return Print writer.
*
* @exception IOException
* Thrown if an I/O error occurred.
*/
private PrintWriter writeHeaders()
throws IOException
{
if (myPrintWriter == null)
{
myPrintWriter =
new PrintWriter
(new OutputStreamWriter
(mySocket.getOutputStream(),
myCharset));
myPrintWriter.write ("HTTP/1.0 " + myStatusCode + "\r\n");
for (Map.Entry entry : myHeaderMap.entrySet())
{
myPrintWriter.write
(entry.getKey() + ": " + entry.getValue() + "\r\n");
}
myPrintWriter.write ("\r\n");
}
return myPrintWriter;
}
// Unit test main program.
// /**
// * Unit test main program. The program listens for connections to
// * localhost:8080. The program reads each HTTP request from a web browser
// * and merely echoes the request data back to the browser.
// *
// * Usage: java edu.rit.http.HttpResponse
// */
// public static void main
// (String[] args)
// throws Exception
// {
// ServerSocket serversocket = new ServerSocket();
// serversocket.bind (new InetSocketAddress ("localhost", 8080));
// for (;;)
// {
// Socket socket = serversocket.accept();
// HttpRequest request = new HttpRequest (socket);
// HttpResponse response = new HttpResponse (socket);
// if (request.isValid())
// {
// PrintWriter out = response.getPrintWriter();
// out.println ("");
// out.println ("
");
// out.println ("");
// out.println ("");
// out.println ("");
// out.println ("- ");
// out.print ("Method = \"");
// out.print (request.getMethod());
// out.println ("\"");
// out.println ("
- ");
// out.print ("URI = \"");
// out.print (request.getUri());
// out.println ("\"");
// out.println ("
- ");
// out.print ("Version = \"");
// out.print (request.getHttpVersion());
// out.println ("\"");
// for (Map.Entry
entry : request.getHeaders())
// {
// out.println ("- ");
// out.print ("Header name = \"");
// out.print (entry.getKey());
// out.print ("\", value = \"");
// out.print (entry.getValue());
// out.println ("\"");
// }
// out.println ("
");
// out.println ("");
// out.println ("");
// }
// else
// {
// response.setStatusCode (Status.STATUS_400_BAD_REQUEST);
// PrintWriter out = response.getPrintWriter();
// out.println ("");
// out.println ("");
// out.println ("");
// out.println ("");
// out.println ("");
// out.println ("400 Bad Request");
// out.println ("
");
// out.println ("You idiot.");
// out.println ("");
// out.println ("");
// }
// response.close();
// }
// }
}
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