nmode's Git Repositories - signal-cli/blob - src/main/java/org/asamk/signal/http/ServerSentEventSender.java

   1 package org.asamk.signal.http;
   2
   3 import java.io.BufferedWriter;
   4 import java.io.IOException;
   5 import java.io.OutputStream;
   6 import java.io.OutputStreamWriter;
   7 import java.nio.charset.StandardCharsets;
   8 import java.util.List;
   9
  10 /**
  11  * This class send Server-sent events payload to an OutputStream.
  12  * See <a href="https://html.spec.whatwg.org/multipage/server-sent-events.html">spec</a>
  13  */
  14 public class ServerSentEventSender {
  15
  16     private final BufferedWriter writer;
  17
  18     public ServerSentEventSender(final OutputStream outputStream) {
  19         this.writer = new BufferedWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
  20     }
  21
  22     /**
  23      * @param id    Event id
  24      * @param event Event type
  25      * @param data  Event data, each entry must not contain newline chars.
  26      */
  27     public synchronized void sendEvent(String id, String event, List<String> data) throws IOException {
  28         if (id != null) {
  29             writer.write("id:");
  30             writer.write(id);
  31             writer.write("\n");
  32         }
  33         if (event != null) {
  34             writer.write("event:");
  35             writer.write(event);
  36             writer.write("\n");
  37         }
  38         if (data.isEmpty()) {
  39             writer.write("data\n");
  40         } else {
  41             for (final var d : data) {
  42                 writer.write("data:");
  43                 writer.write(d);
  44                 writer.write("\n");
  45             }
  46         }
  47         writer.write("\n");
  48         writer.flush();
  49     }
  50
  51     public synchronized void sendKeepAlive() throws IOException {
  52         writer.write(":\n");
  53         writer.flush();
  54     }
  55 }