package com.example.myapplication;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
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.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;

public class MainActivity extends ActionBarActivity  implements MqttCallback{

    private MqttClient mqttClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public void clickButton(View button){
        switch (button.getId()){
            case R.id.register:
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        int qos             = 2;
                        String broker       = "tcp://iot.eclipse.org:1883";
                        EditText editTextID = (EditText)findViewById(R.id.id);
                        String clientId     =  editTextID.getText().toString();
                        MemoryPersistence persistence = new MemoryPersistence();
                        try{
                            mqttClient = new MqttClient(broker, clientId, persistence);
                            MqttConnectOptions connOpts = new MqttConnectOptions();
                            connOpts.setCleanSession(true);
                            mqttClient.connect(connOpts);
                            mqttClient.subscribe(clientId);
                            mqttClient.setCallback(MainActivity.this);
                            runOnUiThread(new Runnable() {
                                public void run() {
                                    Toast.makeText(getApplicationContext(), mqttClient.isConnected() ? "连接成功" : "连接失败", Toast.LENGTH_LONG).show();
                                }
                            });
                        }
                        catch (Exception e){
                            e.printStackTrace();
                        }

                    }
                }).start();
                break;
            case R.id.send:
                EditText editTextTargetID =(EditText)findViewById(R.id.targetID);
                final String targetID = editTextTargetID.getText().toString();
                String content = ((EditText)findViewById(R.id.content)).getText().toString();
                final MqttMessage message = new MqttMessage(content.getBytes());
                if(mqttClient==null || !mqttClient.isConnected()){
                    Toast.makeText(getApplicationContext(),"MQTT未连接",Toast.LENGTH_LONG).show();
                    return;
                }
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try{
                            mqttClient.publish(targetID, message);
                        }
                        catch (Exception e){
                            e.printStackTrace();
                        }
                    }
                }).start();
                break;
        }
    }

    @Override
    public void connectionLost(final Throwable cause) {
        this.runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), "失去连接：" + cause.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
    }

    @Override
    public void messageArrived(String topic, MqttMessage message)
            throws Exception {
        final String msg = new String(message.getPayload());
        this.runOnUiThread(new Runnable() {
            public void run() {
                Toast.makeText(getApplicationContext(), "收到:"+msg, Toast.LENGTH_LONG).show();
            }
        });
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        try {
            final String msg = new String(token.getMessage().getPayload());
            this.runOnUiThread(new Runnable() {
                public void run() {
                    Toast.makeText(getApplicationContext(), "发送完毕:" + msg, Toast.LENGTH_LONG).show();
                }
            });
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="50dp"
        android:orientation="horizontal">

        <TextView
            android:layout_width="50dp"
            android:layout_height="fill_parent"
            android:gravity="center"
            android:text="ID:"/>

        <EditText
            android:id="@+id/id"
            android:layout_width="100dp"
            android:layout_height="fill_parent" />

        <Button
            android:id="@+id/register"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:text="register"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:onClick="clickButton" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="50dp"
        android:orientation="horizontal">
        <TextView
            android:layout_width="80dp"
            android:layout_height="fill_parent"
            android:gravity="center"
            android:text="接收方ID:"/>
        <EditText
            android:id="@+id/targetID"
            android:layout_width="50dp"
            android:layout_height="fill_parent" />
        <TextView
            android:layout_width="40dp"
            android:layout_height="fill_parent"
            android:gravity="center"
            android:text="内容:"/>
        <EditText
            android:id="@+id/content"
            android:layout_width="100dp"
            android:layout_height="fill_parent" />
        <Button
            android:text="Send"
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_below="@+id/textView"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:onClick="clickButton" />
    </LinearLayout>

</LinearLayout>