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   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 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 /**
  27  * The {@link StreamOutput} Streams mjpeg out to a client
  28  *
  29  * @author Matthew Skinner - Initial contribution
  30  */
  31
  32 @NonNullByDefault
  33 public class StreamOutput {
  34     public final Logger logger = LoggerFactory.getLogger(getClass());
  35     private final HttpServletResponse response;
  36     private final String boundary;
  37     private String contentType;
  38     private final ServletOutputStream output;
  39     private BlockingQueue<byte[]> fifo = new ArrayBlockingQueue<byte[]>(50);
  40     private boolean connected = false;
  41     public boolean isSnapshotBased = false;
  42
  43     public StreamOutput(HttpServletResponse response) throws IOException {
  44         boundary = "thisMjpegStream";
  45         contentType = "multipart/x-mixed-replace; boundary=" + boundary;
  46         this.response = response;
  47         output = response.getOutputStream();
  48         isSnapshotBased = true;
  49     }
  50
  51     public StreamOutput(HttpServletResponse response, String contentType) throws IOException {
  52         boundary = "";
  53         this.contentType = contentType;
  54         this.response = response;
  55         output = response.getOutputStream();
  56         if (!contentType.isEmpty()) {
  57             sendInitialHeaders();
  58             connected = true;
  59         }
  60     }
  61
  62     public void sendSnapshotBasedFrame(byte[] currentSnapshot) throws IOException {
  63         String header = "--" + boundary + "\r\n" + "Content-Type: image/jpeg" + "\r\n" + "Content-Length: "
  64                 + currentSnapshot.length + "\r\n\r\n";
  65         if (!connected) {
  66             sendInitialHeaders();
  67             // iOS needs to have two jpgs sent for the picture to appear instantly.
  68             output.write(header.getBytes());
  69             output.write(currentSnapshot);
  70             output.write("\r\n".getBytes());
  71             connected = true;
  72         }
  73         output.write(header.getBytes());
  74         output.write(currentSnapshot);
  75         output.write("\r\n".getBytes());
  76     }
  77
  78     public void queueFrame(byte[] frame) {
  79         try {
  80             fifo.add(frame);
  81         } catch (IllegalStateException e) {
  82             logger.debug("FIFO buffer has run out of space:{}", e.getMessage());
  83             fifo.remove();
  84             fifo.add(frame);
  85         }
  86     }
  87
  88     public void updateContentType(String contentType) {
  89         this.contentType = contentType;
  90         if (!connected) {
  91             sendInitialHeaders();
  92             connected = true;
  93         }
  94     }
  95
  96     public void sendFrame() throws IOException, InterruptedException {
  97         if (isSnapshotBased) {
  98             sendSnapshotBasedFrame(fifo.take());
  99         } else if (connected) {
 100             output.write(fifo.take());
 101         }
 102     }
 103
 104     private void sendInitialHeaders() {
 105         response.setContentType(contentType);
 106         response.setHeader("Access-Control-Allow-Origin", "*");
 107         response.setHeader("Access-Control-Expose-Headers", "*");
 108     }
 109
 110     public void close() {
 111         try {
 112             output.close();
 113         } catch (IOException e) {
 114         }
 115     }
 116 }