Start Watch Service API

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Execution

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Start watcher enables you to manually start the watch service. Submit the following request to start the watch service:

StartWatchServiceRequest request = new StartWatchServiceRequest();

Response

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The returned AcknowledgeResponse contains a value on whether or not the request was received:

boolean isAcknowledged = response.isAcknowledged(); 

A boolean value of true if successfully received, false otherwise.

Synchronous Execution

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When executing a StartWatchServiceRequest in the following manner, the client waits for the StartWatchServiceResponse to be returned before continuing with code execution:

AcknowledgedResponse response = client.watcher().startWatchService(request, RequestOptions.DEFAULT);

Asynchronous Execution

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Executing a StartWatchServiceRequest can also be done in an asynchronous fashion so that the client can return directly. Users need to specify how the response or potential failures will be handled by passing the request and a listener to the asynchronous start-watch-service method:

client.watcher().startWatchServiceAsync(request, RequestOptions.DEFAULT, listener); 

The StartWatchServiceRequest to execute and the ActionListener to use when the execution completes

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed.

A typical listener for start-watch-service looks like:

ActionListener<AcknowledgedResponse> listener = new ActionListener<AcknowledgedResponse>() {
    @Override
    public void onResponse(AcknowledgedResponse response) {
        
    }

    @Override
    public void onFailure(Exception e) {
        
    }
};

Called when the execution is successfully completed.

Called when the whole StartWatchServiceRequest fails.