一、概述
本项目制作了一个手机端APP,一个遥控器,通过MQTT协议连接阿里云,实现对下位机的操控,并监控下位机的状态。使用Paho接入物联网平台,参考阿里云Paho-MQTT Android接入示例。鉴于阿里云示例项目使用的android studio版本较老,且恰逢android studio 2022.3.1版本发布,本项目就使用了最新的版本完成该项目。
二、开发步骤
1、工程创建
工程创建和之前的版本没有太大区别,这里就不详述了。
2、导入库文件
这里使用了两个库文件,一个是org.eclipse.paho.client.mqttv3-1.2.5.jar,另一个是org.eclipse.paho.android.service-1.1.1.jar。实际上,后面这个库可以不用的,这里用它的原因是mqtt库不支持自动重连,而后面这个库支持。导入方法有两种:一是如下图所示,直接下载文件包粘贴到app下的libs文件夹下,右键导入即可;另一种就是在app模块的build.gradle文件中implementation,效果是一样的。网络不好的情况还是建议使用第一种方法。
3、添加依赖
在工程的settings.gradle中添加Paho仓库地址。
4、添加support-v4对应的兼容包
5、开启网络权限,添加服务
6、代码编写
6.1布局
xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:background="#c0ffff" tools:context=".MainActivity"> android:layout_width="match_parent" android:layout_height="80dp"/> android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:weightSum="4"> android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"/> android:layout_width="60dp" android:layout_height="match_parent" android:text="状态:" android:textSize="30dp" android:layout_weight="1"/> android:id="@+id/textView" android:layout_width="60dp" android:layout_height="match_parent" android:background="#FFFFFF" android:gravity="center" android:text=" " android:textSize="30dp" android:layout_weight="1"/> android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"/> android:layout_width="match_parent" android:layout_height="80dp"/> android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:weightSum="5"> android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"/> android:layout_width="match_parent" android:layout_height="30dp"/> android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:gravity="center" android:weightSum="5"> android:id="@+id/btn_pause" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="25dp" android:text="暂停" /> android:layout_width="match_parent" android:layout_height="30dp"/> android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:weightSum="5"> android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"/> android:id="@+id/btn_lock" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="25dp" android:text="锁门" /> android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"/> android:id="@+id/btn_unlock" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:textSize="25dp" android:text="解锁" /> android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"/>
6.1运行代码
package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import org.eclipse.paho.android.service.MqttAndroidClient;
import org.eclipse.paho.client.mqttv3.IMqttActionListener;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.IMqttToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.json.JSONException;
import org.json.JSONObject;
import java.math.BigInteger;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
/**************************************************************/
public class MainActivity extends AppCompatActivity {
/* MQTT客户端对象 */
MqttAndroidClient mqttAndroidClient;
final private String TAG = "AiotMqtt";
/* 设备三元组信息 */
final private String PRODUCTKEY = "";//填自己的
final private String DEVICENAME = "";//填自己的
final private String DEVICESECRET = "";//填自己的
/* 自动Topic, 用于上报消息 */
final private String PUB_TOPIC = "/" + PRODUCTKEY + "/" + DEVICENAME + "/user/update";
/* 自动Topic, 用于接受消息 */
final private String SUB_TOPIC = "/" + PRODUCTKEY + "/" + DEVICENAME + "/user/get";
/* 阿里云Mqtt服务器域名 */
final String host = "tcp://" + PRODUCTKEY + ".iot-as-mqtt.cn-shanghai.aliyuncs.com:1883";
private String clientId;
private String userName;
private String passWord;
/************************************************************/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/* MQTT初始化 */
mqttInit();
/* MQTT连接 */
mqttConnect();
/* 通过按键发布消息 */
Button[] arrButton = new Button[5];
buttonInit(arrButton);
buttonHandler(arrButton,Color.BLUE, Color.RED);
}/* onCreate */
/************************************************************
*
************************************************************/
/* MQTT初始化函数 */
private void mqttInit() {
/* 获取Mqtt建连信息clientId, username, password */
AiotMqttOption aiotMqttOption = new AiotMqttOption().getMqttOption(PRODUCTKEY, DEVICENAME, DEVICESECRET);
if (aiotMqttOption == null) {
Log.e(TAG, "device info error");
} else {
clientId = aiotMqttOption.getClientId();
userName = aiotMqttOption.getUsername();
passWord = aiotMqttOption.getPassword();
}
/* 创建MqttAndroidClient对象, 并设置回调接口 */
mqttAndroidClient = new MqttAndroidClient(getApplicationContext(), host, clientId);
mqttAndroidClient.setCallback(new MqttCallback() {
@Override
public void connectionLost(Throwable cause) {
Log.i(TAG, "connection lost");
}
@Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
Log.i(TAG, "topic: " + topic + ", msg: " + new String(message.getPayload()));
String payload = new String(message.getPayload());
TextView recText = findViewById(R.id.textView);
recText.setText(jsonParser(payload));
}
@Override
public void deliveryComplete(IMqttDeliveryToken token) {
Log.i(TAG, "msg delivered");
}
});
}
/************************************************************/
/* MQTT连接函数 */
private void mqttConnect() {
/* 创建MqttConnectOptions对象并配置username和password */
MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
mqttConnectOptions.setUserName(userName);
mqttConnectOptions.setPassword(passWord.toCharArray());
/* Mqtt建连 */
try {
mqttAndroidClient.connect(mqttConnectOptions,null, new IMqttActionListener() {
@Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.i(TAG, "connect succeed");
subscribeTopic(SUB_TOPIC);
}
@Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.i(TAG, "connect failed");
}
});
} catch (MqttException e) {
e.printStackTrace();
}
} /* mqttConnect */
/************************************************************/
/**
* 订阅特定的主题
* @param topic mqtt主题
*/
public void subscribeTopic(String topic) {
try {
mqttAndroidClient.subscribe(topic, 0, null, new IMqttActionListener() {
@Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.i(TAG, "subscribed succeed");
}
@Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.i(TAG, "subscribed failed");
}
});
} catch (MqttException e) {
e.printStackTrace();
}
} /* subscribeTopic */
/************************************************************/
/**
* 向默认的主题/user/update发布消息
* @param payload 消息载荷
*/
public void publishMessage(String payload) {
try {
if (!mqttAndroidClient.isConnected()) {
mqttAndroidClient.connect();
}
MqttMessage message = new MqttMessage();
message.setPayload(payload.getBytes());
message.setQos(0);
mqttAndroidClient.publish(PUB_TOPIC, message,null, new IMqttActionListener() {
@Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.i(TAG, "publish succeed!");
}
@Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.i(TAG, "publish failed!");
}
});
} catch (MqttException e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
} /* publishMessage */
/************************************************************/
/**
* MQTT建连选项类,输入设备三元组productKey, deviceName和deviceSecret, 生成Mqtt建连参数clientId,username和password.
*/
static class AiotMqttOption {
private String username = "";//填自己的
private String password = "";//填自己的
private String clientId = "";//填自己的
public String getUsername() { return this.username;}
public String getPassword() { return this.password;}
public String getClientId() { return this.clientId;}
/**
* 获取Mqtt建连选项对象
* @param productKey 产品秘钥
* @param deviceName 设备名称
* @param deviceSecret 设备机密
* @return AiotMqttOption对象或者NULL
*/
public AiotMqttOption getMqttOption(String productKey, String deviceName, String deviceSecret) {
if (productKey == null || deviceName == null || deviceSecret == null) {
return null;
}
try {
String timestamp = Long.toString(System.currentTimeMillis());
// clientId
this.clientId = productKey + "." + deviceName + "|timestamp=" + timestamp +
",_v=paho-android-1.0.0,securemode=2,signmethod=hmacsha256|";
// userName
this.username = deviceName + "&" + productKey;
// password
String macSrc = "clientId" + productKey + "." + deviceName + "deviceName" +
deviceName + "productKey" + productKey + "timestamp" + timestamp;
String algorithm = "HmacSHA256";
Mac mac = Mac.getInstance(algorithm);
SecretKeySpec secretKeySpec = new SecretKeySpec(deviceSecret.getBytes(), algorithm);
mac.init(secretKeySpec);
byte[] macRes = mac.doFinal(macSrc.getBytes());
password = String.format("%064x", new BigInteger(1, macRes));
} catch (Exception e) {
e.printStackTrace();
return null;
}
return this;
}
} /* class AiotMqttOption */
/************************************************************/
/* 按键初始化函数 */
private void buttonInit(Button[] buttons){
for (int i = 0; i < buttons.length; ++i) {
switch (i){
case 0:
buttons[i] = findViewById(R.id.btn_open);
break;
case 1:
buttons[i] = findViewById(R.id.btn_close);
break;
case 2:
buttons[i] = findViewById(R.id.btn_pause);
break;
case 3:
buttons[i] = findViewById(R.id.btn_lock);
break;
case 4:
buttons[i] = findViewById(R.id.btn_unlock);
break;
}
}
} /* buttonInit */
/************************************************************/
@SuppressLint("ClickableViewAccessibility")
private void buttonHandler(Button[] button, int fColor, int bColor) {
for (int i = 0; i < button.length; ++i) {
int j = i;
button[i].setBackgroundColor(fColor);
button[i].setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
button[j].setBackgroundColor(bColor);
} else {
button[j].setBackgroundColor(fColor);
switch (j) {
case 0:
publishMessage("{\"state\":\"OPEN\"}");
break;
case 1:
publishMessage("{\"state\":\"CLOSE\"}");
break;
case 2:
publishMessage("{\"state\":\"PAUSE\"}");
break;
case 3:
publishMessage("{\"state\":\"LOCK\"}");
break;
case 4:
publishMessage("{\"state\":\"UNLOCK\"}");
break;
}
}
return false;
}
});
}
}/* buttonHandler */
/************************************************************/
/* json解析函数 */
private String jsonParser(String strIn){
String strOut = null;
/* 解析json数据 */
try {
JSONObject jsonObject = new JSONObject(strIn);
strOut = jsonObject.getString("state");
} catch (JSONException e) {
e.printStackTrace();
}
return strOut;
}
} /* MainActivity */
精彩文章
发表评论