src/main/java/org/java_websocket/AbstractWebSocket.java
public void setConnectionLostTimeout( int connectionLostTimeout ) {
        synchronized (syncConnectionLost) {
            this.connectionLostTimeout = TimeUnit.SECONDS.toNanos(connectionLostTimeout);
            if (this.connectionLostTimeout <= 0) {
                log.trace("Connection lost timer stopped");
                cancelConnectionLostTimer();
                return;
            }
            if (this.websocketRunning) {
                log.trace("Connection lost timer restarted");
                //Reset all the pings
                try {
                    ArrayList<WebSocket> connections = new ArrayList<WebSocket>(getConnections());
                    WebSocketImpl webSocketImpl;
                    for (WebSocket conn : connections) {
                        if (conn instanceof WebSocketImpl) {
                            webSocketImpl = (WebSocketImpl) conn;
                            webSocketImpl.updateLastPong();
                        }
                    }
                } catch (Exception e) {
                    log.error("Exception during connection lost restart", e);
                }
                restartConnectionLostTimer();
            }
        }
    }
public void setConnectionLostTimeout( int connectionLostTimeout ) {
        synchronized (syncConnectionLost) {
            this.connectionLostTimeout = TimeUnit.SECONDS.toNanos(connectionLostTimeout);
            if (this.connectionLostTimeout <= 0) {
                log.trace("Connection lost timer stopped");
                cancelConnectionLostTimer();
                return;
            }
            if (this.websocketRunning) {
                log.trace("Connection lost timer restarted");
                //Reset all the pings
                try {
                    ArrayList<WebSocket> connections = new ArrayList<WebSocket>(getConnections());
                    WebSocketImpl webSocketImpl;
                    for (WebSocket conn : connections) {
                        if (conn instanceof WebSocketImpl) {
                            webSocketImpl = (WebSocketImpl) conn;
                            webSocketImpl.updateLastPong();
                        }
                    }
                } catch (Exception e) {
                    log.error("Exception during connection lost restart", e);
                }
                restartConnectionLostTimer();
            }
        }
    }
Setter for the interval checking for lost connections
A value lower or equal 0 results in the check to be deactivated

@param connectionLostTimeout the interval in seconds
@since 1.3.4