ios push notifiycation

昨天搞了许久的苹果的推送服务，看着文档不是很难。可是很少使用socket发送拼接字节一类的数据。后来找到了javapns，很方便。直接就推送成功了。
本来是想用netty做的，但是没有成功，我觉得是bytes的发送格式不对，特别是字节数。


主页：http://code.google.com/p/javapns/
使用的前提：http://code.google.com/p/javapns/wiki/GeneralRequirements
推送的简单例子:http://code.google.com/p/javapns/wiki/PushNotificationBasic

主页的wiki里面有不少例子和文档。使用推送的前提是要生成证书和要推送的设备令牌。
设备令牌是客户端程序第一次安装时生成的，apple的文档中有很详细的图，并提交给自己的push server。

apple的文档有c代码的例子，下面是一段从javapns截取的推送代码。

KeyStore ts = KeyStore.getInstance("PKCS12");
		ts.load(new FileInputStream("d:/spncert.p12"), "123456".toCharArray());
		KeyManagerFactory tmf = KeyManagerFactory.getInstance("SunX509");
		tmf.init(ts, "123456".toCharArray());

		SSLContext sslContext = SSLContext.getInstance("TLS");
		sslContext.init(tmf.getKeyManagers(), null, null);
		SSLSocketFactory factory = sslContext.getSocketFactory();

		SSLSocket socket = (SSLSocket) factory.createSocket(host, port);
		String[] suites = socket.getSupportedCipherSuites();
		socket.setEnabledCipherSuites(suites);
		// start handshake
		socket.startHandshake();

		char[] t = token.toCharArray();
		byte[] b = Arrays.toString(t).getBytes();

		OutputStream outputstream = socket.getOutputStream();

		byte[] deviceTokenAsBytes = new byte[token.length() / 2];
		token = token.toUpperCase();
		int j = 0;
		try {
			for (int i = 0; i < token.length(); i += 2) {
				String tt = token.substring(i, i + 2);
				int tmp = Integer.parseInt(tt, 16);
				deviceTokenAsBytes[j++] = (byte) tmp;
			}
		} catch (NumberFormatException e1) {
			throw new InvalidDeviceTokenFormatException(token, e1.getMessage());
		}
		// Create the ByteArrayOutputStream which will contain the raw interface
		byte[] payloadAsBytes = payload.getBytes();
		int size = (Byte.SIZE / Byte.SIZE) + (Character.SIZE / Byte.SIZE)
				+ deviceTokenAsBytes.length + (Character.SIZE / Byte.SIZE)
				+ payloadAsBytes.length;
		ByteArrayOutputStream bao = new ByteArrayOutputStream(size);

		// Write command to ByteArrayOutputStream
		// 0 = simple
		// 1 = enhanced
		byte zeron = 0;
		bao.write(zeron);
		// Write the TokenLength as a 16bits unsigned int, in big endian
		int tl = deviceTokenAsBytes.length;
		bao.write(intTo2ByteArray(tl));

		// Write the Token in bytes
		bao.write(deviceTokenAsBytes);

		// Write the PayloadLength as a 16bits unsigned int, in big endian
		int pl = payloadAsBytes.length;
		bao.write(intTo2ByteArray(pl));

		// Finally write the Payload
		bao.write(payloadAsBytes);
		bao.flush();

		outputstream.write(bao.toByteArray());
		outputstream.flush();
		outputstream.close();
	}

	static final byte[] intTo2ByteArray(int value) {
		int s1 = (value & 0xFF00) >> 8;
		int s2 = value & 0xFF;
		return new byte[] { (byte) s1, (byte) s2 };
	}

上面代码中的：byte[] deviceTokenAsBytes = new byte[token.length() / 2];很重要。我看到这恍然大悟。。。。哎