git.basschouten.com Git - openhab-addons.git/blob

   1 /**
   2  * Copyright (c) 2010-2022 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.ipcamera.internal.servlet;
  14
  15 import java.io.IOException;
  16 import java.util.concurrent.ArrayBlockingQueue;
  17 import java.util.concurrent.BlockingQueue;
  18
  19 import javax.servlet.ServletOutputStream;
  20 import javax.servlet.http.HttpServletResponse;
  21
  22 import org.eclipse.jdt.annotation.NonNullByDefault;
  23
  24 /**
  25  * The {@link StreamOutput} Streams mjpeg out to a client
  26  *
  27  * @author Matthew Skinner - Initial contribution
  28  */
  29
  30 @NonNullByDefault
  31 public class StreamOutput {
  32     private final HttpServletResponse response;
  33     private final String boundary;
  34     private String contentType;
  35     private final ServletOutputStream output;
  36     private BlockingQueue<byte[]> fifo = new ArrayBlockingQueue<byte[]>(6);
  37     private boolean connected = false;
  38     public boolean isSnapshotBased = false;
  39
  40     public StreamOutput(HttpServletResponse response) throws IOException {
  41         boundary = "thisMjpegStream";
  42         contentType = "multipart/x-mixed-replace; boundary=" + boundary;
  43         this.response = response;
  44         output = response.getOutputStream();
  45         isSnapshotBased = true;
  46     }
  47
  48     public StreamOutput(HttpServletResponse response, String contentType) throws IOException {
  49         boundary = "";
  50         this.contentType = contentType;
  51         this.response = response;
  52         output = response.getOutputStream();
  53         if (!contentType.isEmpty()) {
  54             sendInitialHeaders();
  55             connected = true;
  56         }
  57     }
  58
  59     public void sendSnapshotBasedFrame(byte[] currentSnapshot) throws IOException {
  60         String header = "--" + boundary + "\r\n" + "Content-Type: image/jpeg" + "\r\n" + "Content-Length: "
  61                 + currentSnapshot.length + "\r\n\r\n";
  62         if (!connected) {
  63             sendInitialHeaders();
  64             // iOS needs to have two jpgs sent for the picture to appear instantly.
  65             output.write(header.getBytes());
  66             output.write(currentSnapshot);
  67             output.write("\r\n".getBytes());
  68             connected = true;
  69         }
  70         output.write(header.getBytes());
  71         output.write(currentSnapshot);
  72         output.write("\r\n".getBytes());
  73     }
  74
  75     public void queueFrame(byte[] frame) {
  76         try {
  77             fifo.add(frame);
  78         } catch (IllegalStateException e) {
  79             fifo.remove();
  80             fifo.add(frame);
  81         }
  82     }
  83
  84     public void updateContentType(String contentType) {
  85         this.contentType = contentType;
  86         if (!connected) {
  87             sendInitialHeaders();
  88             connected = true;
  89         }
  90     }
  91
  92     public void sendFrame() throws IOException, InterruptedException {
  93         if (isSnapshotBased) {
  94             sendSnapshotBasedFrame(fifo.take());
  95         } else if (connected) {
  96             output.write(fifo.take());
  97         }
  98     }
  99
 100     private void sendInitialHeaders() {
 101         response.setContentType(contentType);
 102         response.setHeader("Access-Control-Allow-Origin", "*");
 103         response.setHeader("Access-Control-Expose-Headers", "*");
 104     }
 105
 106     public void close() {
 107         try {
 108             output.close();
 109         } catch (IOException e) {
 110         }
 111     }
 112 }