JavaPNS使用与吐槽
苹果平台开发的应用程序，不支持后台运行程序，所以苹果有一个推送服务在软件的一些信息推送给用户。
JAVA中，有一个开源软件，JavaPNS实现了Java平台中连接苹果服务器与推送消息的服务。但是在使用的过程中，有两点需要使用者注意一下，希望后续使用的同志们能避免我走过的覆辙。
1、一是向苹果的服务推送消息时，如果遇到无效的deviceToken,苹果会断开网络连接，而JavaPNS不会进行重连。苹果原文：
If you send a notification and APNs finds the notification malformed or otherwise unintelligible, it returns an error-response packet prior to disconnecting. (If there is no error, APNs doesn’t return anything.) Figure 5-3 depicts the format of the error-response packet.
2、JavaPNS是一条条发送通知的，但是对于大规模发送的生产环境，显然是不可以的，建议使用批量发送。苹果原文：
The binary interface employs a plain TCP socket for binary content that is streaming in nature. For optimum performance, you should batch multiple notifications in a single transmission over the interface, either explicitly or using a TCP/IP Nagle algorithm.
对于此，我对JavaAPNS的代码进行了改动，使其支持批量发送和苹果断开重连，但是有一个问题需要大家注意一下，在正常发送的情况下，苹果是不会向Socket中写任何数据的，需要等待其读超时，this.socket.getInputStream().read()，确订推送结果的正常。通过持续的向Socket中写数据，实现批量发送，调用flush方法时，完成一次批量发送。在PushNotificationManager增加如下方法：
public List<ResponsePacket> sendNotification(List<PushedNotification> pnl) {logger.info(psn + "RR批量推送时消息体的大小为：" + pnl.size());List<ResponsePacket> failList = new ArrayList<ResponsePacket>();if (pnl.size() == 0) {return failList;}Set<Integer> sendSet = new HashSet<Integer>();int counter = 0;while (counter < pnl.size()) {try {this.socket.setSoTimeout(3000);this.socket.setSendBufferSize(25600);this.socket.setReceiveBufferSize(600);for (; counter < pnl.size(); counter++) {PushedNotification push = pnl.get(counter);if (sendSet.contains(push.getIdentifier())) {logger.warn("信息[" + push.getIdentifier() + "]已经被推送");continue;}byte[] bytes = getMessage(push.getDevice().getToken(), push.getPayload(), push.getIdentifier(), push);this.socket.getOutputStream().write(bytes);// 考虑到重发的问题// sendSet.add(push.getIdentifier());}this.socket.getOutputStream().flush();// 等待回馈数据，比单个发送时延时长一点，否则将无法获取到回馈数据this.socket.setSoTimeout(1000);StringBuffer allResult = new StringBuffer();ResponsePacket rp = new ResponsePacket();int readCounter = 0;// 处理读回写数据的异常try {logger.info(psn + "检查流数据是否可用:" + this.socket.getInputStream().available());byte[] sid = new byte[4];// 发送标记while (true) {int value = this.socket.getInputStream().read();if (value < 0) {break;}readCounter++;if (readCounter == 1) {rp.setCommand(value);}if (readCounter == 2) {rp.setStatus(value);}if (readCounter >= 3 && readCounter <= 6) {sid[readCounter - 3] = (byte) value;if (readCounter == 6) {rp.setIdentifier(ByteBuffer.wrap(sid).getInt());if (failList.contains(rp)) {logger.error("错误返馈数据中已经包含当前数据，" + rp.getIdentifier());}failList.add(rp);}}allResult.append(value + "_");}this.socket.getInputStream().close();} catch (SocketTimeoutException ste) {logger.debug(psn + "消息推送成功，无任何返回!", ste);} catch (IOException e) {logger.debug(psn + "消息推送成功，关闭连接流时出错!", e);}logger.info("苹果返回的数据为：" + allResult.toString());if (readCounter >= 6) {// 找到出错的地方for (int i = 0; i < pnl.size(); i++) {PushedNotification push = pnl.get(i);if (push.getIdentifier() == rp.getIdentifier()) {counter = i + 1;break;// 从出错的地方再次发送,}}try {this.createNewSocket();} catch (Exception e) {logger.warn("连接时出错,", e);}}} catch (SSLHandshakeException she) {// 握手出错，标记不加logger.warn("SHE消息推送时出错,", she);try {this.createNewSocket();} catch (Exception e) {logger.warn("连接时出错,", e);}} catch (SocketException se) {logger.warn("SE消息推送时出错", se);counter++;try {this.createNewSocket();} catch (Exception e) {logger.warn("连接时出错,", e);}} catch (IOException e) {logger.warn("IE消息推送时出错", e);counter++;} catch (Exception e) {logger.warn("E消息推送时出错", e);counter++;}if (counter >= pnl.size()) {break;}}return failList;}