Tomcat example source code file (HttpServlet.java)

This example Tomcat source code file (HttpServlet.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

allow_delete, crlf, httpservletresponse, httpservletresponse, io, ioexception, ioexception, method, nobodyoutputstream, nobodyresponse, printwriter, reflection, servlet, servletexception, servletexception, string, string, text, util

The Tomcat HttpServlet.java source code

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.servlet.http;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Method;
import java.text.MessageFormat;
import java.util.Enumeration;
import java.util.Locale;
import java.util.ResourceBundle;

import javax.servlet.GenericServlet;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;


/**
 *
 * Provides an abstract class to be subclassed to create
 * an HTTP servlet suitable for a Web site. A subclass of
 * <code>HttpServlet must override at least 
 * one method, usually one of these:
 *
 * <ul>
 * <li> doGet, if the servlet supports HTTP GET requests
 * <li> doPost, for HTTP POST requests
 * <li> doPut, for HTTP PUT requests
 * <li> doDelete, for HTTP DELETE requests
 * <li> init and destroy, 
 * to manage resources that are held for the life of the servlet
 * <li> getServletInfo, which the servlet uses to
 * provide information about itself 
 * </ul>
 *
 * <p>There's almost no reason to override the service
 * method. <code>service handles standard HTTP
 * requests by dispatching them to the handler methods
 * for each HTTP request type (the <code>doXXX
 * methods listed above).
 *
 * <p>Likewise, there's almost no reason to override the 
 * <code>doOptions and doTrace methods.
 * 
 * <p>Servlets typically run on multithreaded servers,
 * so be aware that a servlet must handle concurrent
 * requests and be careful to synchronize access to shared resources.
 * Shared resources include in-memory data such as
 * instance or class variables and external objects
 * such as files, database connections, and network 
 * connections.
 * See the
 * <a href="http://java.sun.com/Series/Tutorial/java/threads/multithreaded.html">
 * Java Tutorial on Multithreaded Programming</a> for more
 * information on handling multiple threads in a Java program.
 *
 * @author	Various
 * @version	$Version$
 *
 */



public abstract class HttpServlet extends GenericServlet
    implements java.io.Serializable
{
    private static final String METHOD_DELETE = "DELETE";
    private static final String METHOD_HEAD = "HEAD";
    private static final String METHOD_GET = "GET";
    private static final String METHOD_OPTIONS = "OPTIONS";
    private static final String METHOD_POST = "POST";
    private static final String METHOD_PUT = "PUT";
    private static final String METHOD_TRACE = "TRACE";

    private static final String HEADER_IFMODSINCE = "If-Modified-Since";
    private static final String HEADER_LASTMOD = "Last-Modified";
    
    private static final String LSTRING_FILE =
	"javax.servlet.http.LocalStrings";
    private static ResourceBundle lStrings =
	ResourceBundle.getBundle(LSTRING_FILE);
   
   
   
    
    /**
     * Does nothing, because this is an abstract class.
     * 
     */

    public HttpServlet() { }
    
    

    /**
     *
     * Called by the server (via the <code>service method) to
     * allow a servlet to handle a GET request. 
     *
     * <p>Overriding this method to support a GET request also
     * automatically supports an HTTP HEAD request. A HEAD
     * request is a GET request that returns no body in the
     * response, only the request header fields.
     *
     * <p>When overriding this method, read the request data,
     * write the response headers, get the response's writer or 
     * output stream object, and finally, write the response data.
     * It's best to include content type and encoding. When using
     * a <code>PrintWriter object to return the response,
     * set the content type before accessing the
     * <code>PrintWriter object.
     *
     * <p>The servlet container must write the headers before
     * committing the response, because in HTTP the headers must be sent
     * before the response body.
     *
     * <p>Where possible, set the Content-Length header (with the
     * {@link javax.servlet.ServletResponse#setContentLength} method),
     * to allow the servlet container to use a persistent connection 
     * to return its response to the client, improving performance.
     * The content length is automatically set if the entire response fits
     * inside the response buffer.
     *
     * <p>When using HTTP 1.1 chunked encoding (which means that the response
     * has a Transfer-Encoding header), do not set the Content-Length header.
     *
     * <p>The GET method should be safe, that is, without
     * any side effects for which users are held responsible.
     * For example, most form queries have no side effects.
     * If a client request is intended to change stored data,
     * the request should use some other HTTP method.
     *
     * <p>The GET method should also be idempotent, meaning
     * that it can be safely repeated. Sometimes making a
     * method safe also makes it idempotent. For example, 
     * repeating queries is both safe and idempotent, but
     * buying a product online or modifying data is neither
     * safe nor idempotent. 
     *
     * <p>If the request is incorrectly formatted, doGet
     * returns an HTTP "Bad Request" message.
     * 
     *
     * @param req	an {@link HttpServletRequest} object that
     *			contains the request the client has made
     *			of the servlet
     *
     * @param resp	an {@link HttpServletResponse} object that
     *			contains the response the servlet sends
     *			to the client
     * 
     * @exception IOException	if an input or output error is 
     *				detected when the servlet handles
     *				the GET request
     *
     * @exception ServletException	if the request for the GET
     *					could not be handled
     *
     * 
     * @see javax.servlet.ServletResponse#setContentType
     *
     */

    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException
    {
	String protocol = req.getProtocol();
	String msg = lStrings.getString("http.method_get_not_supported");
	if (protocol.endsWith("1.1")) {
	    resp.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, msg);
	} else {
	    resp.sendError(HttpServletResponse.SC_BAD_REQUEST, msg);
	}
    }





    /**
     *
     * Returns the time the <code>HttpServletRequest
     * object was last modified,
     * in milliseconds since midnight January 1, 1970 GMT.
     * If the time is unknown, this method returns a negative
     * number (the default).
     *
     * <p>Servlets that support HTTP GET requests and can quickly determine
     * their last modification time should override this method.
     * This makes browser and proxy caches work more effectively,
     * reducing the load on server and network resources.
     *
     *
     * @param req	the <code>HttpServletRequest 
     *			object that is sent to the servlet
     *
     * @return		a <code>long integer specifying
     *			the time the <code>HttpServletRequest
     *			object was last modified, in milliseconds
     *			since midnight, January 1, 1970 GMT, or
     *			-1 if the time is not known
     *
     */

    protected long getLastModified(HttpServletRequest req) {
	return -1;
    }




    /**
     * 
     *
     * <p>Receives an HTTP HEAD request from the protected
     * <code>service method and handles the
     * request.
     * The client sends a HEAD request when it wants
     * to see only the headers of a response, such as
     * Content-Type or Content-Length. The HTTP HEAD
     * method counts the output bytes in the response
     * to set the Content-Length header accurately.
     *
     * <p>If you override this method, you can avoid computing
     * the response body and just set the response headers
     * directly to improve performance. Make sure that the
     * <code>doHead method you write is both safe
     * and idempotent (that is, protects itself from being
     * called multiple times for one HTTP HEAD request).
     *
     * <p>If the HTTP HEAD request is incorrectly formatted,
     * <code>doHead returns an HTTP "Bad Request"
     * message.
     *
     *
     * @param req	the request object that is passed
     *			to the servlet
     *			
     * @param resp	the response object that the servlet
     *			uses to return the headers to the clien
     *
     * @exception IOException		if an input or output error occurs
     *
     * @exception ServletException	if the request for the HEAD
     *					could not be handled
     */

    protected void doHead(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException
    {
	NoBodyResponse response = new NoBodyResponse(resp);
	
	doGet(req, response);
	response.setContentLength();
    }
    




    /**
     *
     * Called by the server (via the <code>service method)
     * to allow a servlet to handle a POST request.
     *
     * The HTTP POST method allows the client to send
     * data of unlimited length to the Web server a single time
     * and is useful when posting information such as
     * credit card numbers.
     *
     * <p>When overriding this method, read the request data,
     * write the response headers, get the response's writer or output
     * stream object, and finally, write the response data. It's best 
     * to include content type and encoding. When using a
     * <code>PrintWriter object to return the response, set the 
     * content type before accessing the <code>PrintWriter object. 
     *
     * <p>The servlet container must write the headers before committing the
     * response, because in HTTP the headers must be sent before the 
     * response body.
     *
     * <p>Where possible, set the Content-Length header (with the
     * {@link javax.servlet.ServletResponse#setContentLength} method),
     * to allow the servlet container to use a persistent connection 
     * to return its response to the client, improving performance.
     * The content length is automatically set if the entire response fits
     * inside the response buffer.  
     *
     * <p>When using HTTP 1.1 chunked encoding (which means that the response
     * has a Transfer-Encoding header), do not set the Content-Length header. 
     *
     * <p>This method does not need to be either safe or idempotent.
     * Operations requested through POST can have side effects for
     * which the user can be held accountable, for example, 
     * updating stored data or buying items online.
     *
     * <p>If the HTTP POST request is incorrectly formatted,
     * <code>doPost returns an HTTP "Bad Request" message.
     *
     *
     * @param req	an {@link HttpServletRequest} object that
     *			contains the request the client has made
     *			of the servlet
     *
     * @param resp	an {@link HttpServletResponse} object that
     *			contains the response the servlet sends
     *			to the client
     * 
     * @exception IOException	if an input or output error is 
     *				detected when the servlet handles
     *				the request
     *
     * @exception ServletException	if the request for the POST
     *					could not be handled
     *
     *
     * @see javax.servlet.ServletOutputStream
     * @see javax.servlet.ServletResponse#setContentType
     *
     *
     */

    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException
    {
	String protocol = req.getProtocol();
	String msg = lStrings.getString("http.method_post_not_supported");
	if (protocol.endsWith("1.1")) {
	    resp.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, msg);
	} else {
	    resp.sendError(HttpServletResponse.SC_BAD_REQUEST, msg);
	}
    }




    /**
     * Called by the server (via the <code>service method)
     * to allow a servlet to handle a PUT request.
     *
     * The PUT operation allows a client to 
     * place a file on the server and is similar to 
     * sending a file by FTP.
     *
     * <p>When overriding this method, leave intact
     * any content headers sent with the request (including
     * Content-Length, Content-Type, Content-Transfer-Encoding,
     * Content-Encoding, Content-Base, Content-Language, Content-Location,
     * Content-MD5, and Content-Range). If your method cannot
     * handle a content header, it must issue an error message
     * (HTTP 501 - Not Implemented) and discard the request.
     * For more information on HTTP 1.1, see RFC 2616
     * <a href="http://www.ietf.org/rfc/rfc2616.txt">.
     *
     * <p>This method does not need to be either safe or idempotent.
     * Operations that <code>doPut performs can have side
     * effects for which the user can be held accountable. When using
     * this method, it may be useful to save a copy of the
     * affected URL in temporary storage.
     *
     * <p>If the HTTP PUT request is incorrectly formatted,
     * <code>doPut returns an HTTP "Bad Request" message.
     *
     *
     * @param req	the {@link HttpServletRequest} object that
     *			contains the request the client made of
     *			the servlet
     *
     * @param resp	the {@link HttpServletResponse} object that
     *			contains the response the servlet returns
     *			to the client
     *
     * @exception IOException	if an input or output error occurs
     *				while the servlet is handling the
     *				PUT request
     *
     * @exception ServletException	if the request for the PUT
     *					cannot be handled
     *
     */
  
    protected void doPut(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException
    {
	String protocol = req.getProtocol();
	String msg = lStrings.getString("http.method_put_not_supported");
	if (protocol.endsWith("1.1")) {
	    resp.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, msg);
	} else {
	    resp.sendError(HttpServletResponse.SC_BAD_REQUEST, msg);
	}
    }




    /**
     * 
     * Called by the server (via the <code>service method)
     * to allow a servlet to handle a DELETE request.
     *
     * The DELETE operation allows a client to remove a document
     * or Web page from the server.
     * 
     * <p>This method does not need to be either safe
     * or idempotent. Operations requested through
     * DELETE can have side effects for which users
     * can be held accountable. When using
     * this method, it may be useful to save a copy of the
     * affected URL in temporary storage.
     *
     * <p>If the HTTP DELETE request is incorrectly formatted,
     * <code>doDelete returns an HTTP "Bad Request"
     * message.
     *
     *
     * @param req	the {@link HttpServletRequest} object that
     *			contains the request the client made of
     *			the servlet
     *
     *
     * @param resp	the {@link HttpServletResponse} object that
     *			contains the response the servlet returns
     *			to the client				
     *
     *
     * @exception IOException	if an input or output error occurs
     *				while the servlet is handling the
     *				DELETE request
     *
     * @exception ServletException	if the request for the
     *					DELETE cannot be handled
     *
     */
     
    protected void doDelete(HttpServletRequest req,
			    HttpServletResponse resp)
	throws ServletException, IOException
    {
	String protocol = req.getProtocol();
	String msg = lStrings.getString("http.method_delete_not_supported");
	if (protocol.endsWith("1.1")) {
	    resp.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, msg);
	} else {
	    resp.sendError(HttpServletResponse.SC_BAD_REQUEST, msg);
	}
    }
    

    private static Method[] getAllDeclaredMethods(Class c) {

        if (c.equals(javax.servlet.http.HttpServlet.class)) {
            return null;
        }

        Method[] parentMethods = getAllDeclaredMethods(c.getSuperclass());
        Method[] thisMethods = c.getDeclaredMethods();
	
        if ((parentMethods != null) && (parentMethods.length > 0)) {
            Method[] allMethods =
                new Method[parentMethods.length + thisMethods.length];
	    System.arraycopy(parentMethods, 0, allMethods, 0,
                             parentMethods.length);
	    System.arraycopy(thisMethods, 0, allMethods, parentMethods.length,
                             thisMethods.length);

	    thisMethods = allMethods;
	}

	return thisMethods;
    }


    /**
     * Called by the server (via the <code>service method)
     * to allow a servlet to handle a OPTIONS request.
     *
     * The OPTIONS request determines which HTTP methods 
     * the server supports and
     * returns an appropriate header. For example, if a servlet
     * overrides <code>doGet, this method returns the
     * following header:
     *
     * <p>Allow: GET, HEAD, TRACE, OPTIONS
     *
     * <p>There's no need to override this method unless the
     * servlet implements new HTTP methods, beyond those 
     * implemented by HTTP 1.1.
     *
     * @param req	the {@link HttpServletRequest} object that
     *			contains the request the client made of
     *			the servlet
     *
     *
     * @param resp	the {@link HttpServletResponse} object that
     *			contains the response the servlet returns
     *			to the client				
     *
     *
     * @exception IOException	if an input or output error occurs
     *				while the servlet is handling the
     *				OPTIONS request
     *
     * @exception ServletException	if the request for the
     *					OPTIONS cannot be handled
     *
     */
         
    protected void doOptions(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException
    {
	Method[] methods = getAllDeclaredMethods(this.getClass());
	
	boolean ALLOW_GET = false;
	boolean ALLOW_HEAD = false;
	boolean ALLOW_POST = false;
	boolean ALLOW_PUT = false;
	boolean ALLOW_DELETE = false;
	boolean ALLOW_TRACE = true;
	boolean ALLOW_OPTIONS = true;
	
	for (int i=0; i<methods.length; i++) {
	    Method m = methods[i];
	    
	    if (m.getName().equals("doGet")) {
		ALLOW_GET = true;
		ALLOW_HEAD = true;
	    }
	    if (m.getName().equals("doPost")) 
		ALLOW_POST = true;
	    if (m.getName().equals("doPut"))
		ALLOW_PUT = true;
	    if (m.getName().equals("doDelete"))
		ALLOW_DELETE = true;
	    
	}
	
	String allow = null;
	if (ALLOW_GET)
	    if (allow==null) allow=METHOD_GET;
	if (ALLOW_HEAD)
	    if (allow==null) allow=METHOD_HEAD;
	    else allow += ", " + METHOD_HEAD;
	if (ALLOW_POST)
	    if (allow==null) allow=METHOD_POST;
	    else allow += ", " + METHOD_POST;
	if (ALLOW_PUT)
	    if (allow==null) allow=METHOD_PUT;
	    else allow += ", " + METHOD_PUT;
	if (ALLOW_DELETE)
	    if (allow==null) allow=METHOD_DELETE;
	    else allow += ", " + METHOD_DELETE;
	if (ALLOW_TRACE)
	    if (allow==null) allow=METHOD_TRACE;
	    else allow += ", " + METHOD_TRACE;
	if (ALLOW_OPTIONS)
	    if (allow==null) allow=METHOD_OPTIONS;
	    else allow += ", " + METHOD_OPTIONS;
	
	resp.setHeader("Allow", allow);
    }
    
    
    
    
    /**
     * Called by the server (via the <code>service method)
     * to allow a servlet to handle a TRACE request.
     *
     * A TRACE returns the headers sent with the TRACE
     * request to the client, so that they can be used in
     * debugging. There's no need to override this method. 
     *
     *
     *
     * @param req	the {@link HttpServletRequest} object that
     *			contains the request the client made of
     *			the servlet
     *
     *
     * @param resp	the {@link HttpServletResponse} object that
     *			contains the response the servlet returns
     *			to the client				
     *
     *
     * @exception IOException	if an input or output error occurs
     *				while the servlet is handling the
     *				TRACE request
     *
     * @exception ServletException	if the request for the
     *					TRACE cannot be handled
     *
     */

    protected void doTrace(HttpServletRequest req, HttpServletResponse resp) 
	throws ServletException, IOException
    {
	
	int responseLength;
	
	String CRLF = "\r\n";
	String responseString = "TRACE "+ req.getRequestURI()+
	    " " + req.getProtocol();
	
	Enumeration reqHeaderEnum = req.getHeaderNames();
	
	while( reqHeaderEnum.hasMoreElements() ) {
	    String headerName = (String)reqHeaderEnum.nextElement();
	    responseString += CRLF + headerName + ": " +
		req.getHeader(headerName); 
	}
	
	responseString += CRLF;
	
	responseLength = responseString.length();
	
	resp.setContentType("message/http");
	resp.setContentLength(responseLength);
	ServletOutputStream out = resp.getOutputStream();
	out.print(responseString);	
	out.close();
	return;
    }		





    /**
     *
     * Receives standard HTTP requests from the public
     * <code>service method and dispatches
     * them to the <code>doXXX methods defined in 
     * this class. This method is an HTTP-specific version of the 
     * {@link javax.servlet.Servlet#service} method. There's no
     * need to override this method.
     *
     *
     *
     * @param req	the {@link HttpServletRequest} object that
     *			contains the request the client made of
     *			the servlet
     *
     *
     * @param resp	the {@link HttpServletResponse} object that
     *			contains the response the servlet returns
     *			to the client				
     *
     *
     * @exception IOException	if an input or output error occurs
     *				while the servlet is handling the
     *				HTTP request
     *
     * @exception ServletException	if the HTTP request
     *					cannot be handled
     * 
     * @see 				javax.servlet.Servlet#service
     *
     */

    protected void service(HttpServletRequest req, HttpServletResponse resp)
	throws ServletException, IOException
    {
	String method = req.getMethod();

	if (method.equals(METHOD_GET)) {
	    long lastModified = getLastModified(req);
	    if (lastModified == -1) {
		// servlet doesn't support if-modified-since, no reason
		// to go through further expensive logic
		doGet(req, resp);
	    } else {
		long ifModifiedSince = req.getDateHeader(HEADER_IFMODSINCE);
		if (ifModifiedSince < (lastModified / 1000 * 1000)) {
		    // If the servlet mod time is later, call doGet()
                    // Round down to the nearest second for a proper compare
                    // A ifModifiedSince of -1 will always be less
		    maybeSetLastModified(resp, lastModified);
		    doGet(req, resp);
		} else {
		    resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
		}
	    }

	} else if (method.equals(METHOD_HEAD)) {
	    long lastModified = getLastModified(req);
	    maybeSetLastModified(resp, lastModified);
	    doHead(req, resp);

	} else if (method.equals(METHOD_POST)) {
	    doPost(req, resp);
	    
	} else if (method.equals(METHOD_PUT)) {
	    doPut(req, resp);	
	    
	} else if (method.equals(METHOD_DELETE)) {
	    doDelete(req, resp);
	    
	} else if (method.equals(METHOD_OPTIONS)) {
	    doOptions(req,resp);
	    
	} else if (method.equals(METHOD_TRACE)) {
	    doTrace(req,resp);
	    
	} else {
	    //
	    // Note that this means NO servlet supports whatever
	    // method was requested, anywhere on this server.
	    //

	    String errMsg = lStrings.getString("http.method_not_implemented");
	    Object[] errArgs = new Object[1];
	    errArgs[0] = method;
	    errMsg = MessageFormat.format(errMsg, errArgs);
	    
	    resp.sendError(HttpServletResponse.SC_NOT_IMPLEMENTED, errMsg);
	}
    }
    




    /*
     * Sets the Last-Modified entity header field, if it has not
     * already been set and if the value is meaningful.  Called before
     * doGet, to ensure that headers are set before response data is
     * written.  A subclass might have set this header already, so we
     * check.
     */

    private void maybeSetLastModified(HttpServletResponse resp,
				      long lastModified) {
	if (resp.containsHeader(HEADER_LASTMOD))
	    return;
	if (lastModified >= 0)
	    resp.setDateHeader(HEADER_LASTMOD, lastModified);
    }
   
   
   
    
    /**
     *
     * Dispatches client requests to the protected
     * <code>service method. There's no need to
     * override this method.
     *
     * 
     * @param req	the {@link HttpServletRequest} object that
     *			contains the request the client made of
     *			the servlet
     *
     *
     * @param res	the {@link HttpServletResponse} object that
     *			contains the response the servlet returns
     *			to the client				
     *
     *
     * @exception IOException	if an input or output error occurs
     *				while the servlet is handling the
     *				HTTP request
     *
     * @exception ServletException	if the HTTP request cannot
     *					be handled
     *
     * 
     * @see javax.servlet.Servlet#service
     *
     */

    public void service(ServletRequest req, ServletResponse res)
	throws ServletException, IOException
    {
	HttpServletRequest	request;
	HttpServletResponse	response;
	
	try {
	    request = (HttpServletRequest) req;
	    response = (HttpServletResponse) res;
	} catch (ClassCastException e) {
	    throw new ServletException("non-HTTP request or response");
	}
	service(request, response);
    }
}




/*
 * A response that includes no body, for use in (dumb) "HEAD" support.
 * This just swallows that body, counting the bytes in order to set
 * the content length appropriately.  All other methods delegate directly
 * to the HTTP Servlet Response object used to construct this one.
 */
// file private
class NoBodyResponse implements HttpServletResponse {
    private HttpServletResponse		resp;
    private NoBodyOutputStream		noBody;
    private PrintWriter			writer;
    private boolean			didSetContentLength;

    // file private
    NoBodyResponse(HttpServletResponse r) {
	resp = r;
	noBody = new NoBodyOutputStream();
    }

    // file private
    void setContentLength() {
	if (!didSetContentLength)
	  resp.setContentLength(noBody.getContentLength());
    }


    // SERVLET RESPONSE interface methods

    public void setContentLength(int len) {
	resp.setContentLength(len);
	didSetContentLength = true;
    }

    public void setCharacterEncoding(String charset)
      { resp.setCharacterEncoding(charset); }

    public void setContentType(String type)
      { resp.setContentType(type); }

    public String getContentType()
      { return resp.getContentType(); }

    public ServletOutputStream getOutputStream() throws IOException
      { return noBody; }

    public String getCharacterEncoding()
	{ return resp.getCharacterEncoding(); }

    public PrintWriter getWriter() throws UnsupportedEncodingException
    {
	if (writer == null) {
	    OutputStreamWriter	w;

	    w = new OutputStreamWriter(noBody, getCharacterEncoding());
	    writer = new PrintWriter(w);
	}
	return writer;
    }

    public void setBufferSize(int size) throws IllegalStateException
      { resp.setBufferSize(size); }

    public int getBufferSize()
      { return resp.getBufferSize(); }

    public void reset() throws IllegalStateException
      { resp.reset(); }
      
      public void resetBuffer() throws IllegalStateException
      { resp.resetBuffer(); }

    public boolean isCommitted()
      { return resp.isCommitted(); }

    public void flushBuffer() throws IOException
      { resp.flushBuffer(); }

    public void setLocale(Locale loc)
      { resp.setLocale(loc); }

    public Locale getLocale()
      { return resp.getLocale(); }


    // HTTP SERVLET RESPONSE interface methods

    public void addCookie(Cookie cookie)
      { resp.addCookie(cookie); }

    public boolean containsHeader(String name)
      { return resp.containsHeader(name); }

    /** @deprecated */
    public void setStatus(int sc, String sm)
      { resp.setStatus(sc, sm); }

    public void setStatus(int sc)
      { resp.setStatus(sc); }

    public void setHeader(String name, String value)
      { resp.setHeader(name, value); }

    public void setIntHeader(String name, int value)
      { resp.setIntHeader(name, value); }

    public void setDateHeader(String name, long date)
      { resp.setDateHeader(name, date); }

    public void sendError(int sc, String msg) throws IOException
      { resp.sendError(sc, msg); }

    public void sendError(int sc) throws IOException
      { resp.sendError(sc); }

    public void sendRedirect(String location) throws IOException
      { resp.sendRedirect(location); }
    
    public String encodeURL(String url) 
      { return resp.encodeURL(url); }

    public String encodeRedirectURL(String url)
      { return resp.encodeRedirectURL(url); }
      
    public void addHeader(String name, String value)
      { resp.addHeader(name, value); }
      
    public void addDateHeader(String name, long value)
      { resp.addDateHeader(name, value); }
      
    public void addIntHeader(String name, int value)
      { resp.addIntHeader(name, value); }
      
      
      

    /**
     * @deprecated	As of Version 2.1, replaced by
     * 			{@link HttpServletResponse#encodeURL}.
     *
     */
     
     
    public String encodeUrl(String url) 
      { return this.encodeURL(url); }
      
      
      
      
      
      
      

    /**
     * @deprecated	As of Version 2.1, replaced by
     *			{@link HttpServletResponse#encodeRedirectURL}.
     *
     */
     
     
    public String encodeRedirectUrl(String url)
      { return this.encodeRedirectURL(url); }

}







/*
 * Servlet output stream that gobbles up all its data.
 */
 
// file private
class NoBodyOutputStream extends ServletOutputStream {

    private static final String LSTRING_FILE =
	"javax.servlet.http.LocalStrings";
    private static ResourceBundle lStrings =
	ResourceBundle.getBundle(LSTRING_FILE);

    private int		contentLength = 0;

    // file private
    NoBodyOutputStream() {}

    // file private
    int getContentLength() {
	return contentLength;
    }

    public void write(int b) {
	contentLength++;
    }

    public void write(byte buf[], int offset, int len)
	throws IOException
    {
	if (len >= 0) {
	    contentLength += len;
	} else {
	    // XXX
	    // isn't this really an IllegalArgumentException?
	    
	    String msg = lStrings.getString("err.io.negativelength");
	    throw new IOException("negative length");
	}
    }
}