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Microsoft Azure IoTHub Serials 2 - 如何为android应用添加IoTHub支持
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1. 在build.gradle（app）文件的dependencies中添加对以下项的依赖：
'com.microsoft.azure.sdk.iot:iot-device-client:1.5.37'
其中后面的1.5.37是版本号，最新的版本可以到这里查：
http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.microsoft.azure.sdk.iot%22
2. 在build.gradle（app）文件的packagingOptions中添加如下内容
packagingOptions {
exclude "META-INF/MSFTSIG.SF"
exclude "META-INF/MSFTSIG.RSA"
exclude 'META-INF/DEPENDENCIES'
exclude 'META-INF/NOTICE'
exclude 'META-INF/LICENSE'
exclude 'META-INF/LICENSE.txt'
exclude 'META-INF/NOTICE.txt'
exclude 'thirdpartynotice.txt'
}
如下图所示。
3. 在需要与IoTHub交互的java文件中，引入如下package
//Azure IoTHub packages import com.microsoft.azure.sdk.iot.device.DeviceClient; import com.microsoft.azure.sdk.iot.device.IotHubClientProtocol; import com.microsoft.azure.sdk.iot.device.IotHubEventCallback; import com.microsoft.azure.sdk.iot.device.IotHubMessageResult; import com.microsoft.azure.sdk.iot.device.IotHubStatusCode; import com.microsoft.azure.sdk.iot.device.Message;
4. 添加如下全局的连接字符串
//Azure IoTHub private final String connString = "HostName=************.azure-devices.net;DeviceId=***********;SharedAccessKey=*********************"; private final String deviceId = "*****************";
5. 在java文件中添加如下3个类（MessageCallbackMqtt、EventCallback、MessageCallback和Counter）的声明
// Our MQTT doesn't support abandon/reject, so we will only display the messaged received
// from IoTHub and return COMPLETE
static class MessageCallbackMqtt implements com.microsoft.azure.sdk.iot.device.MessageCallback
{
public IotHubMessageResult execute(Message msg, Object context)
{
Counter counter = (Counter) context;
System.out.println(
"Received message " + counter.toString()
+ " with content: " + new String(msg.getBytes(), Message.DEFAULT_IOTHUB_MESSAGE_CHARSET));
counter.increment();
return IotHubMessageResult.COMPLETE;
}
}
static class EventCallback implements IotHubEventCallback
{
public void execute(IotHubStatusCode status, Object context)
{
Integer i = (Integer) context;
System.out.println("IoT Hub responded to message " + i.toString()
+ " with status " + status.name());
}
}
static class MessageCallback implements com.microsoft.azure.sdk.iot.device.MessageCallback
{
public IotHubMessageResult execute(Message msg, Object context)
{
Counter counter = (Counter) context;
System.out.println(
"Received message " + counter.toString()
+ " with content: " + new String(msg.getBytes(), Message.DEFAULT_IOTHUB_MESSAGE_CHARSET));
int switchVal = counter.get() % 3;
IotHubMessageResult res;
switch (switchVal)
{
case 0:
res = IotHubMessageResult.COMPLETE;
break;
case 1:
res = IotHubMessageResult.ABANDON;
break;
case 2:
res = IotHubMessageResult.REJECT;
break;
default:
// should never happen.
throw new IllegalStateException("Invalid message result specified.");
}
System.out.println("Responding to message " + counter.toString() + " with " + res.name());
counter.increment();
return res;
}
}
/**
* Used as a counter in the message callback.
*/
static class Counter
{
int num;
Counter(int num) {
this.num = num;
}
int get() {
return this.num;
}
void increment() {
this.num++;
}
@Override
public String toString() {
return Integer.toString(this.num);
}
}
6.需要发送数据时，调用以下代码段
private void SendMessage() throws URISyntaxException, IOException
{
// Comment/uncomment from lines below to use HTTPS or MQTT protocol
// IotHubClientProtocol protocol = IotHubClientProtocol.HTTPS;
IotHubClientProtocol protocol = IotHubClientProtocol.MQTT; DeviceClient client = new DeviceClient(connString, protocol); try
{
client.open();
} catch (Exception e2)
{
System.err.println("Exception while opening IoTHub connection: " + e2.toString());
} //发送message填充
String msgStr = "{\"deviceId\":\"" + deviceId + ",\"PM25\":" + PM25 + ",\"PM10\":" + PM10 + "}";
try
{
Message msg = new Message(msgStr);
msg.setProperty("PMAlert", PM25 > 100 ? "true" : "false");
msg.setMessageId(java.util.UUID.randomUUID().toString());
System.out.println(msgStr);
EventCallback eventCallback = new EventCallback();
client.sendEventAsync(msg, eventCallback, null);
} catch (Exception e)
{
System.err.println("Exception while sending event: " + e.getMessage());
}
try
{
Thread.sleep(2000);
} catch (InterruptedException e)
{
e.printStackTrace();
} client.closeNow();
}
