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/*
* Copyright (c) 2011 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.eclipse.leshan.server.demo.utils;
import java.io.IOException;
/**
*
* {@link EventSource} is the passive half of an event source connection, as defined by the EventSource Specification.
*
*
* {@link EventSource.Emitter} is the active half of the connection and allows to operate on the connection.
*
*
* {@link EventSource} allows applications to be notified of events happening on the connection; two events are being
* notified: the opening of the event source connection, where method {@link EventSource#onOpen(Emitter)} is invoked,
* and the closing of the event source connection, where method {@link EventSource#onClose()} is invoked.
*
*
* @see EventSourceServlet
*/
public interface EventSource {
/**
*
* Callback method invoked when an event source connection is opened.
*
*
* @param emitter the {@link Emitter} instance that allows to operate on the connection
* @throws IOException if the implementation of the method throws such exception
*/
public void onOpen(Emitter emitter) throws IOException;
/**
*
* Callback method invoked when an event source connection is closed.
*
*/
public void onClose();
/**
*
* {@link Emitter} is the active half of an event source connection, and allows applications to operate on the
* connection by sending events, data or comments, or by closing the connection.
*
*
* An {@link Emitter} instance will be created for each new event source connection.
*
*
* {@link Emitter} instances are fully thread safe and can be used from multiple threads.
*
*/
public interface Emitter {
/**
*
* Sends a named event with data to the client.
*
*
* When invoked as: event("foo", "bar"), the client will receive the lines:
*
*
*
* event: foo
* data: bar
*
*
* @param name the event name
* @param data the data to be sent
* @throws IOException if an I/O failure occurred
* @see #data(String)
*/
public void event(String name, String data) throws IOException;
/**
*
* Sends a default event with data to the client.
*
*
* When invoked as: data("baz"), the client will receive the line:
*
*
*
* data: baz
*
*
* When invoked as: data("foo\r\nbar\rbaz\nbax"), the client will receive the lines:
*
*
*
* data: foo
* data: bar
* data: baz
* data: bax
*
*
* @param data the data to be sent
* @throws IOException if an I/O failure occurred
*/
public void data(String data) throws IOException;
/**
*
* Sends a comment to the client.
*
*
* When invoked as: comment("foo"), the client will receive the line:
*
*
*
* : foo
*
*
* @param comment the comment to send
* @throws IOException if an I/O failure occurred
*/
public void comment(String comment) throws IOException;
/**
*
* Closes this event source connection.
*
*/
public void close();
}
}