multipart.java

这是一个用JAVA编写的小程序是有关JZPUSH的希望会对你有所帮助也对我用所帮助我要下源码就一个

/**
 * Web server PUSH implementation.
 * (adapted from pushlets by Just Objects B.V)
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

/**
 * Handle a multipart HTTP response using multipart MIME.
 */
public class multipart
{
    private String boundary = "End.";
    private static final String CRLF = "\015\012";
    private static final String multipartMimeType = "multipart/x-mixed-replace";
    public ServletOutputStream out = null;

       /**
        * MultiPartResponse constructor.
        */
        public multipart(HttpServletRequest req, HttpServletResponse rsp) throws IOException
        {
		if (!agentCanHandleMultipart(req))
                {
		     throw new IOException("MultiPart MIME not supported by browser (MSIE?)");
		}

		// Make boundary unique
		boundary += Long.toString(System.currentTimeMillis(), 36);
		rsp.setContentType(multipartMimeType+";boundary=\""+boundary+"\"");
		rsp.setHeader("Expires","1 Jan 1971");
		out = rsp.getOutputStream();
		out.print("--"+boundary+CRLF);
		out.flush();

		/* SHOULD WE USE CLOSE FOR HTTP1.1 ????  */
		if ("HTTP/1.1".equals(req.getProtocol()))
                {
			rsp.setHeader("Connection", "close");
		}
        }

        /**
         * Determine if our remote (browser) agent can handle multipart.
         */
        static public boolean agentCanHandleMultipart(HttpServletRequest req) throws IOException
        {
	        String ua = req.getHeader("User-Agent");
		// Fpr now assume only MS Internet Exploder cannot do Multipart
		if (ua != null && ua.indexOf("MSIE") > 0)
                {
		     return false;
		}
		// Assume all others (NS,...) support it
		return true;
	}

	/**
         * Begin a next part containing plain HTML.
         */
	public void beginPart() throws IOException
        {
		beginPart("text/html");
	}

        /**
         * Begin a next part with specified MIME content type.
         */
        public void beginPart(String contentType) throws IOException
        {
		out.print("Content-type: "+contentType+CRLF+CRLF);
        }

	/**
         * End the current part but not the response.
         */
	public void endPart() throws IOException
        {
		endPart(false);
	}

	/** End the entire response. */
	public void endResponse() throws IOException
        {
		endPart(true);
	}

	/**
         * End the current part; optionally ends the response.
         */
        public void endPart(boolean endRsp) throws IOException
        {
          out.print(CRLF+"--"+boundary+(endRsp?"--":"")+CRLF);
          out.flush();
        }
}