android 消息推送时，长连接的使用（websocket）

     首先要说的是在app开发中，消息推送是必不可少的一个功能，方式有多种，现在简单介绍一下我在项目开发中使用的方法，长连接

优点：开发成本低，数据安全，对于服务器压力较小（相对轮询）

缺点：耗电量高，容易被系统kill，需要一定的技术

使用okhttp和封装的websocket包来实现

代码贴出如下：

//长连接的建立
    static OkHttpClient mOkHttpClient;

    private void initWebSocket() {
        mOkHttpClient = new OkHttpClient.Builder()
                .readTimeout(3000, TimeUnit.SECONDS)//设置读取超时时间
                .writeTimeout(3000, TimeUnit.SECONDS)//设置写的超时时间
                .connectTimeout(3000, TimeUnit.SECONDS)//设置连接超时时间
                .build();
        Users users = null;
        try {
            users = MyApplication.db.selector(Users.class).findFirst();
        } catch (DbException e) {
            e.printStackTrace();
        }
        String url = null;
        if (users != null) {
            url = Constant.DB_URL + Constant.PORT + Constant.XHB_DIR + Constant.SEND_PERSONAL_NEWS + "?userId=" + users.getId(); //改成自已服务端的地址
        }


        Request request = new Request.Builder().url(url).build();
        WebSocketCall webSocketCall = WebSocketCall.create(mOkHttpClient, request);
        webSocketCall.enqueue(new WebSocketListener() {
            private final ExecutorService sendExecutor = Executors.newSingleThreadExecutor();
            private WebSocket webSocket;

            @Override
            public void onOpen(WebSocket webSocket, Response response) {
                Log.d("WebSocketCall", "onOpen");
                this.webSocket = webSocket;
            }

            /**
             * 连接失败
             * @param e
             * @param response Present when the failure is a direct result of the response (e.g., failed
             * upgrade, non-101 response code, etc.). {@code null} otherwise.
             */
            @Override
            public void onFailure(IOException e, Response response) {
                Log.d("WebSocketCall", "onFailure");
            }

            /**
             * 接收到消息
             * @param message
             * @throws IOException
             */
            @Override
            public void onMessage(ResponseBody message) throws IOException {
                final RequestBody response;
                Log.d("WebSocketCall", "onMessage:" + message.source().readByteString().utf8());
                String msg = message.source().readByteString().utf8();
                NotificationResponse personalNewses = new Gson().fromJson(msg, NotificationResponse.class);
                updatePersonalNewses(personalNewses);
                //通知栏发送消息
                if (personalNewses != null && personalNewses.getData() != null && personalNewses.getData().size() > 0) {
                    sendNotification(personalNewses.getData().get(0));
                }

                //通知remindFragment个人消息发生了变化
                EventBus.getDefault().post(new MessageEvent("PersonalNewsUpdate"));


                if (message.contentType() == WebSocket.TEXT) {//
                    response = RequestBody.create(WebSocket.TEXT, "你好");//文本格式发送消息
                } else {
                    BufferedSource source = message.source();
                    Log.d("WebSocketCall", "onMessage:" + source.readByteString());
                    response = RequestBody.create(WebSocket.BINARY, source.readByteString());
                }
                message.source().close();
//                sendExecutor.execute(new Runnable() {
//                    @Override
//                    public void run() {
//                        try {
//                            Thread.sleep(1000*60);
//                            webSocket.sendMessage(response);//发送消息
//                        } catch (IOException e) {
//                            e.printStackTrace(System.out);
//                        } catch (InterruptedException e) {
//                            e.printStackTrace();
//                        }
//                    }
//                });
            }

            @Override
            public void onPong(Buffer payload) {
                Log.d("WebSocketCall", "onPong:");
            }


            /**
             * 关闭
             * @param code The RFC-compliant
             * status code.
             * @param reason Reason for close or an empty string.
             */
            @Override
            public void onClose(int code, String reason) {
                sendExecutor.shutdown();
            }
        });
    }

附上websocket包的链接，解压后可直接使用

http://download.csdn.net/detail/leven_martin/9725814