Android studio连接ssh服务器 android studio连接云服务器

新建安卓项目

第一步

第二步

修改代码

在AndroidManifest.xml文件中添加网络状态，确保连接mqtt服务器！

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

下载mqtt jar包

下载地址：https://repo.eclipse.org/content/repositories/paho-releases/org/eclipse/paho/org.eclipse.paho.client.mqttv3/

下载jar包

将Android Studio的文件管理方式修改为项目的方式，将下载好的jar包复制粘贴到app/libs文件夹

然后右键该文件，选择Add as Library

然后将将Android Studio的文件管理方式修改回去即可。

主程序

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    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:layout_gravity="center"

    tools:context=".MainActivity">
<!--添加id就修改layout_gravity、layout_margin布局-->
    <TextView
        android:id="@+id/test1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:layout_gravity="center"
        android:layout_margin="60dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
<!--添加button控件及更改布局参数-->
    <Button
        android:id="@+id/btn0"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:orientation="vertical"/>

</LinearLayout>

MainActivity.java

注意修改第一行的包名为自己的包名

package com.example.android_mqtt;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class MainActivity extends AppCompatActivity {

    private String host = "tcp://192.168.3.146:1883";
    private String userName = "admin";
    private String passWord = "public";
    private String mqtt_id="mqttdemo11";
    private String mqtt_sub_topic = "123"; //为了保证你不受到别人的消息  哈哈
    private String mqtt_pub_topic ="123";


    private int i = 1;
    private Handler handler;
    private MqttClient client;
    private MqttConnectOptions options;
    private ScheduledExecutorService scheduler;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView text1 = findViewById(R.id.test1);
        Button btn = findViewById(R.id.btn0);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                i++;
                publishmessageplus(mqtt_pub_topic,"第一个客户端发送的信息"+String.valueOf(i));//发布消息plus
                btn.setText(String.valueOf(i));
            }
        });

        init();
        startReconnect();
        handler = new Handler() {
            @SuppressLint({"SetTextIl8n", "HandlerLeak"})
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                switch (msg.what) {
                    case 1: //开机校验更新回传
                        break;
                    case 2: //反馈回转
                        break;
                    case 3: //MQTT收到消息回传
                        text1.setText(msg.obj.toString());
                        break;
                    case 30: //连接失败
                        Toast.makeText(MainActivity.this,"连接失败",Toast.LENGTH_SHORT).show();
                        break;
                    case 31: //连接成功
                        Toast.makeText(MainActivity.this,"连接成功",Toast.LENGTH_SHORT).show();
                        try {
                            //client.subscribe(mqtt_sub_topic,2);//订阅
                            client.subscribe(mqtt_sub_topic,0);//订阅
                        } catch (MqttException e) {
                            e.printStackTrace();
                        }
                        publishmessageplus(mqtt_pub_topic,"第一个客户端发送的信息");//发布消息plus
                        break;
                    default:
                        break;
                }
            }
        };
    }

    private void init() {
        try {
            //host为主机名，test为clientid即连接MQTT的客户端ID，一般以客户端唯一标识符表示，MemoryPersistence设置clientid的保存形式，默认为以内存保存
            client = new MqttClient(host, mqtt_id,
                    new MemoryPersistence());
            //MQTT的连接设置
            options = new MqttConnectOptions();
            //设置是否清空session,这里如果设置为false表示服务器会保留客户端的连接记录，这里设置为true表示每次连接到服务器都以新的身份连接
            options.setCleanSession(true);
            //设置连接的用户名
            options.setUserName(userName);
            //设置连接的密码
            options.setPassword(passWord.toCharArray());
            // 设置超时时间 单位为秒
            options.setConnectionTimeout(10);
            // 设置会话心跳时间 单位为秒 服务器会每隔1.5*20秒的时间向客户端发送个消息判断客户端是否在线，但这个方法并没有重连的机制
            options.setKeepAliveInterval(20);
            //设置回调
            client.setCallback(new MqttCallback() {
                @Override
                public void connectionLost(Throwable cause) {
                    //连接丢失后，一般在这里面进行重连
                    System.out.println("connectionLost----------");
                }
                @Override
                public void deliveryComplete(IMqttDeliveryToken token) {
                    //publish后会执行到这里
                    System.out.println("deliveryComplete---------"
                            + token.isComplete());
                }
                @Override
                public void messageArrived(String topicName, MqttMessage message)
                        throws Exception {
                    //subscribe后得到的消息会执行到这里面
                    System.out.println("messageArrived----------");
                    Message msg = new Message();
                    msg.what = 3;
                    msg.obj = topicName + "---" + message.toString();
                    handler.sendMessage(msg);
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void Mqtt_connect() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    if (!(client.isConnected())){
                        client.connect(options);
                        Message msg = new Message();
                        msg.what=31;
                        handler.sendMessage(msg);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                    Message msg = new Message();
                    msg.what = 30;
                    handler.sendMessage(msg);
                }
            }
        }).start();
    }

    private void startReconnect() {
        scheduler = Executors.newSingleThreadScheduledExecutor();
        scheduler.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                if (!client.isConnected()) {
                    Mqtt_connect();
                }
            }
        }, 0 * 1000, 10 * 1000, TimeUnit.MILLISECONDS);
    }
    private void publishmessageplus(String topic,String message2)
    {
        if (client == null || !client.isConnected()) {
            return;
        }
        MqttMessage message = new MqttMessage();
        message.setPayload(message2.getBytes());
        try {
            client.publish(topic,message);
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }
}

连接MQTT服务器

搭建本地MQtt服务器参考教程：

将此处的地址修改为本机的ip地址加端口号，如果是使用的emqx的在线服务器可用修改为下面这种形式

wss://xxxx:8084

测试结果

APP

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