如何通过本地Wifi-Hotspot使用AudioStream/AudioGroup

Question

我想创建一个使用音频流/音频组的VoIP系统，可以只使用一个本地WiFi热点功能。我在android device1上创建了一个WiFi热点，并将device2连接到它。当我填写device1的本地IP地址(通过getLocalIPAddress()获得)和device2的IP地址(通过device1上的fetchIPs()方法获得)并在两个设备上单击“连接”时，代码没有抛出任何异常，但我没有听到任何设备的麦克风音频。

Note1:这段代码取自this answer by @murphybro2，稍作修改。Note2:在device1 (主机)上使用getLocalIPAddress()时，ip地址返回为115.163.242.10，而从device2获取的IP格式为192.168.xxx.yyy

我将android.permission.INTERNET、android.permission.ACCESS_WIFI_STATE和android.permission.RECORD_AUDIO放入清单文件中

MainActivity.java：

package com.applications.fihdi.testapp487623;

import android.content.Context;
import android.media.AudioManager;
import android.net.rtp.*;
import android.os.StrictMode;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.format.Formatter;
import android.util.Log;
import android.view.View;
import android.widget.*;

import java.io.*;
import java.net.*;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Enumeration;

public class MainActivity extends AppCompatActivity {

    // Used to load the 'native-lib' library on application startup.
    static {
        System.loadLibrary("native-lib");
    }

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

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);


        try {
            String ip = getLocalIPAddress();
            Log.d("VOIP","String ip: " + ip);

            AudioManager audio = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
            audio.setMode(AudioManager.MODE_IN_COMMUNICATION);
            final AudioGroup m_AudioGroup = new AudioGroup();
            m_AudioGroup.setMode(AudioGroup.MODE_NORMAL);
            final AudioStream m_AudioStream = new AudioStream(InetAddress.getByName(ip));
            Log.d("VOIP","localhost (same as ip??): = " + InetAddress.getLocalHost());

            int localPort = m_AudioStream.getLocalPort();

            Log.d("VOIP","Local Port: "+ Integer.toString(localPort));
            m_AudioStream.setCodec(AudioCodec.PCMU);
            m_AudioStream.setMode(RtpStream.MODE_NORMAL);

            ((TextView) findViewById(R.id.lblLocalPort)).setText(String.valueOf(localPort));

            ((TextView) findViewById(R.id.statusLabel)).setText("Status: local port number generated");

            findViewById(R.id.connectButton).setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    Log.d("VOIP","ConnectButton pressed");
                    String remoteAddress;
                    String remotePort;

                         remoteAddress = ((EditText) findViewById(R.id.editText2)).getText().toString();
                        //String remoteAddress = fetchIPs().get(0);
                         remotePort = ((EditText) findViewById(R.id.editText1)).getText().toString();

                    //Log.d("VOIP", fetchIPs().get(0));

                    try {
                        m_AudioStream.associate(InetAddress.getByName(remoteAddress), Integer.parseInt(remotePort));
                        Log.d("VOIP","AudioStream associated");
                        ((TextView) findViewById(R.id.statusLabel)).setText("Status: connected to: " + fetchIPs().get(0));
                        m_AudioStream.join(m_AudioGroup);
                        Log.d("VOIP","AudioStream joined");
                    } catch (Exception e) {
                        ((TextView) findViewById(R.id.statusLabel)).setText("Couldn't connect");
                        Log.d("VOIP","Exception with associating");
                    }

                }
            });

            findViewById(R.id.DisconnectButton).setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    m_AudioStream.release();
                }
            });

        } catch (Exception e) {
            Log.e("VOIP", "Exception when setting up the Audiostream!");
            e.printStackTrace();
        }
        findViewById(R.id.fetchButtons).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {

                Log.d("VOIP","FetchIp Button pressed");
                ArrayList<String> connectedIPs = fetchIPs();
                ((EditText) findViewById(R.id.editText2)).setText(connectedIPs.get(0));

                for(int i = 0; i<connectedIPs.size(); i++){
                    Log.d("VOIP", "connectedIps[" + i + "]: " + connectedIPs.get(i));
                }
            }
        });

    }

    public String getLocalIPAddress() {
        try {
            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
                NetworkInterface intf = en.nextElement();
                for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
                    InetAddress inetAddress = enumIpAddr.nextElement();
                    if (!inetAddress.isLoopbackAddress()) {
                        String ip = Formatter.formatIpAddress(inetAddress.hashCode());
                        Log.d("VOIP", "***** IP="+ ip);
                        return ip;
                    }
                }
            }
        } catch (SocketException ex) {
            Log.e("VOIP", ex.toString());
        }
        return null;
    }

    public ArrayList<String> fetchIPs() {
        BufferedReader bufRead = null;
        ArrayList<String> result = null;

        try {
            result = new ArrayList<String>();
            bufRead = new BufferedReader(new FileReader("/proc/net/arp"));
            String fileLine;
            while ((fileLine = bufRead.readLine()) != null) {


                String[] splitted = fileLine.split(" +");

                if ((splitted != null) && (splitted.length >= 4)) {

                    String mac = splitted[3];
                    if (mac.matches("..:..:..:..:..:..")) {
                        try {
                            String ping = "ping  -c 1 -W 1 " + splitted[0];
                            Runtime run = Runtime.getRuntime();
                            Process pro = run.exec(ping);
                            try {
                                pro.waitFor();
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                            int exit = pro.exitValue();
                            if (exit == 0) {
                                result.add(splitted[0]);
                            } else {
                                throw new Exception();
                            }
                        } catch (Exception e) {
                            Log.d("MainActivity", "Something went wrong with pinging the adress: " + splitted[0]);
                            Log.d("MainActivity", e.getMessage());
                        }
                    }
                }
            }
        } catch (Exception e) {

        }
            try {
                bufRead.close();
            } catch (Exception e) {

            }



        return result;
    }
}

main_activity.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/lblLocalPort"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/localPort" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:ems="10"
        android:hint="@string/iPHint"
        android:inputType="phone" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:ems="10"
        android:hint="@string/portHint"
        android:inputType="number" >

        <requestFocus />
    </EditText>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp">

        <Button
            android:id="@+id/connectButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/connect" />

        <Button
            android:id="@+id/DisconnectButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/Disconnect" />

        <Button
            android:id="@+id/fetchButtons"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Fetch IPs" />
    </LinearLayout>

    <TextView
        android:id="@+id/statusLabel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />
</LinearLayout>

dimens.xml：

<?xml version="1.0" encoding="utf-8"?>
<resources>
<dimen name="activity_vertical_margin">8dp</dimen>
<dimen name="activity_horizontal_margin">8dp</dimen>
</resources>

Answer 1

getLocalIPAddress()应该会返回Wifi网络接口的IP地址。

在当前代码中，您将返回列表中网络接口的第一个IP地址。

您应该检查netInterface.getName()并与wifi接口名称进行比较，然后返回IP地址。

一旦你的IP地址合适了，你就可以继续了。