This library allows an aplication to connect to Slack to receive and send messages from any channel as if it were a slack client.
The main purpose of this library is to build slack bots able to react to channel events without having to configure any web hook.
The connection is made through the SlackSessionFactory class :
SlackSession session = SlackSessionFactory.
createWebSocketSlackSession("authenticationtoken",true);
session.connect();SlackSession session = SlackSessionFactory.
createWebSocketSlackSession("authenticationtoken", Proxy.Type.HTTP, "myproxy", 1234,true);
session.connect();Slack messages can be retrieved by attaching a SlackMessageListener to the session provided by the factory :
session.addMessagePostedListener(new SlackMessagePostedListener()
{
@Override
public void onEvent(SlackMessagePosted event, SlackSession session)
{
session.sendMessageOverWebSocket(session.findChannelByName("general"), "Message sent : " + event.getMessageContent(), null);
}
});(Since v0.4.0, lambda friendly version)
session.addMessagePostedListener((e, s)
-> s.sendMessageOverWebSocket(s.findChannelByName("general"), "Message sent : " + e.getMessageContent(), null));The SlackSession interface provides various methods to send/modify and delete messages on a given channel :
SlackMessageHandle sendMessage(SlackChannel channel, String message, SlackAttachment attachment);
SlackMessageHandle sendMessage(SlackChannel channel, String message, SlackAttachment attachment, SlackChatConfiguration chatConfiguration);
SlackMessageHandle updateMessage(String timeStamp, SlackChannel channel, String message);
SlackMessageHandle deleteMessage(String timeStamp, SlackChannel channel)(Since v0.4.3, emoji reactions on channel messages)
The SlackSession interface provides a method to add an emoji reaction to a message on a given channel :
SlackMessageHandle addReactionToMessage(SlackChannel channel, String messageTimeStamp, String emojiCode);The following events are handled :
- message post on a channel / group / to the bot
- message update on a channel / group / to the bot
- message delete on a channel / group / to the bot
- channel creation
- channel deletion
- channel archiving
- channel unarchiving
- channel renaming
- private group joining
Here's a full example with an echoing bot using this library :
public class Example
{
public static void main(String[] args) throws Exception
{
final SlackSession session = SlackSessionFactory.
createWebSocketSlackSession("authenticationtoken", Proxy.Type.HTTP, "myproxy", 1234, true);
session.addMessagePostedListener(new SlackMessagePostedListener()
{
@Override
public void onEvent(SlackMessagePosted event, SlackSession session)
{
//let's send a message
SlackMessageHandle handle = session.sendMessage(session.getChannel(),
event.getMessageContent(), null);
try
{
Thread.sleep(2000);
} catch (InterruptedException e)
{
e.printStackTrace();
}
//2 secs later, let's update the message (I can only update my own messages)
session.updateMessage(handle.getSlackReply().getTimestamp(),session.getChannel(),
event.getMessageContent()+" UPDATED");
try
{
Thread.sleep(2000);
} catch (InterruptedException e)
{
e.printStackTrace();
}
//2 secs later, let's now delete the message (I can only delete my own messages)
session.deleteMessage(handle.getSlackReply().getTimestamp(),session.getChannel())
}
});
session.connect();
while (true)
{
Thread.sleep(1000);
}
}
}This library is licensed under the Creative Commons CC0 1.0 Universal license with no warranty (expressed or implied) for any purpose.