JsonChannelListener (Caplin Transformer Java Module SDK 7.1.13-31319-c846df7)

```
public interface JsonChannelListener
```
Interface that must be implemented in order to perform bi-directional communication with a StreamLink client.

The following example shows a basic implementation of JsonChannelListener that accepts all jsonChannels within a namespace and echoes incoming messages back to the StreamLink client:

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`onChannelClose(JsonChannel jsonChannel)`	Callback that informs the `JsonChannelListener` that a StreamLink client wishes to close a channel.
`boolean`	`onChannelOpen(JsonChannel jsonChannel)`	Callback that informs the `JsonChannelListener` that a StreamLink client wishes to open a channel.
`void`	`onMessageReceived(JsonChannel jsonChannel, JsonChannelMessage jsonMessage)`	Callback that informs the `JsonChannelListener` that a StreamLink client has sent a message to the DataSource via a specified channel.

- Method Detail
  - onChannelOpen
```
boolean onChannelOpen(JsonChannel jsonChannel)
```
    Callback that informs the JsonChannelListener that a StreamLink client wishes to open a channel.
    
    Parameters:
    
    jsonChannel - The channel to be opened.
  - onChannelClose
```
void onChannelClose(JsonChannel jsonChannel)
```
    Callback that informs the JsonChannelListener that a StreamLink client wishes to close a channel.
    
    Parameters:
    
    jsonChannel - The channel to be closed.
  - onMessageReceived
```
void onMessageReceived(JsonChannel jsonChannel,
                       JsonChannelMessage jsonMessage)
```
    Callback that informs the JsonChannelListener that a StreamLink client has sent a message to the DataSource via a specified channel.
    
    Parameters:
    
    jsonChannel - The channel receiving the message.
    
    jsonMessage - A message containing fields that have been sent to the DataSource by the StreamLink client.