ServerSentEventHandler.java

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package org.glassfish.sse.api;

import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * A handler that handles Server-Sent Events.
 *
 * @see ServerSentEvent
 * @author Jitendra Kotamraju
 */
public abstract class ServerSentEventHandler {
    protected ServerSentEventConnection connection;

    public enum Status { DONT_RECONNECT, OK }

    /**
     * A callback to indicate that a client connects to receive Server-Sent Events.
     * The application has full access to HTTP request and can decide whether
     * to accept the connection or reject it. In SSE, clients will reconnect
     * if the connection is closed, but can be told to stop reconnecting by
     * returning the appropriate status.
     *
     * <p>
     * Last-Event-ID may be used in determining the status and it can be
     * got using {@code HttpServletRequest.getHeader("Last-Event-ID")}
     *
     * @param request connection request
     * @return Status to accept, or don't reconnect etc
     */
    public Status onConnecting(HttpServletRequest request) {
        return Status.OK;
    }

    /**
     * A callback to indicate that a client connects to receive Server-Sent Events.
     * The application has full access to HTTP request and can decide whether
     * to accept the connection or reject it. In SSE, clients will reconnect
     * if the connection is closed, but can be told to stop reconnecting by
     * returning the appropriate status.
     *
     * @param connection Server-Sert event connection
     * @return Status to accept, or don't reconnect etc
     */
    public void onConnected(ServerSentEventConnection connection) {
        this.connection = connection;
    }

    /**
     * Callback to indicate that the client closed the connection
     */
    public void onClosed() {
    }

}