WebSocketConnectionManager.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.websocket.impl;

import com.google.inject.Inject;

import org.eclipse.che.ide.util.loging.Log;

import javax.inject.Singleton;
import java.util.HashMap;
import java.util.Map;

/**
 * Manages all connection related high level processes. Acts as a facade to low level web socket
 * components.
 *
 * @author Dmitry Kuleshov
 */
@Singleton
public class WebSocketConnectionManager {
    private final WebSocketFactory webSocketFactory;

    private final Map<String, WebSocketConnection> connectionsRegistry = new HashMap<>();

    @Inject
    public WebSocketConnectionManager(WebSocketFactory webSocketFactory) {
        this.webSocketFactory = webSocketFactory;
    }

    /**
     * Initialize a connection. Performs all necessary preparations except for properties management. Must be called before
     * any interactions with a web socket connection.
     *
     * @param url
     *         url of a web socket connection that is to be initialized
     */
    public void initializeConnection(String url) {
        connectionsRegistry.put(url, webSocketFactory.create(url));
    }

    /**
     * Establishes a web socket connection to an endpoint defined by a URL parameter
     *
     * @param url
     *         url of a web socket connection that is to be established
     */
    public void establishConnection(String url) {
        final WebSocketConnection webSocketConnection = connectionsRegistry.get(url);

        if (webSocketConnection == null) {
            final String error = "No connection with url: " + url + "is initialized. Run 'initializedConnection' first.";
            Log.error(getClass(), error);
            throw new IllegalStateException(error);
        }

        webSocketConnection.open();

        Log.debug(getClass(), "Opening connection. Url: " + url);
    }

    /**
     * Close a web socket connection to an endpoint defined by a URL parameter
     *
     * @param url
     *         url of a connection to be closed
     */
    public void closeConnection(String url) {
        final WebSocketConnection webSocketConnection = connectionsRegistry.get(url);

        if (webSocketConnection == null) {
            final String warning = "Closing connection that is not registered and seem like does not exist";
            Log.warn(getClass(), warning);
            throw new IllegalStateException(warning);
        }

        webSocketConnection.close();
        Log.debug(WebSocketConnectionManager.class, "Closing connection.");
    }

    /**
     * Sends a message to a specified endpoint over web socket connection.
     *
     * @param url
     *         url of an endpoint the message is adressed to
     * @param message
     *         plain text message
     */
    public void sendMessage(String url, String message) {
        final WebSocketConnection webSocketConnection = connectionsRegistry.get(url);

        if (webSocketConnection == null) {
            final String error = "No connection with url: " + url + "is initialized. Run 'initializedConnection' first.";
            Log.error(getClass(), error);
            throw new IllegalStateException(error);
        }

        webSocketConnection.send(message);
        Log.debug(getClass(), "Sending message: " + message);
    }

    /**
     * Checks if a connection is opened at the moment
     *
     * @param url
     *         url of a web socket connection to be checked
     *
     * @return connection status: true if opened, false if else
     */
    public boolean isConnectionOpen(String url) {
        final WebSocketConnection webSocketConnection = connectionsRegistry.get(url);

        return webSocketConnection != null && webSocketConnection.isOpen();
    }
}