[移动开发]安卓简单app《录音机》实现

做了一个测试系统录音权限的app,也算是一个简单版的录音机吧，实现了录音和播放功能，代码已经整理好。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/prgress_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:textSize="40sp"
        android:textStyle="bold"
        android:text="0"
        android:layout_marginTop="20dp"
        android:layout_marginBottom="20dp"
        />
    <Button
        android:id="@+id/StartRecordAndSave_btn"
        android:text="StartRecordAndSave"
        android:textSize="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:layout_marginBottom="20dp"
        />

    <Button
        android:id="@+id/PlayRecordAudio_btn"
        android:text="PlayRecordAudio"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:layout_marginTop="20dp"
        android:layout_marginBottom="20dp"
         />

</LinearLayout>

activity_permissions.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    tools:context=".PermissionsActivity">

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.example.myapplication;

import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.content.Intent;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.Toolbar;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class MainActivity extends AppCompatActivity implements MediaPlayer.OnCompletionListener,MediaPlayer.OnPreparedListener {
    private static final int REQUEST_CODE = 0; // 请求码

    // 所需的全部权限
    static final String[] PERMISSIONS = new String[]{
            //Manifest.permission.RECORD_AUDIO,
            Manifest.permission.RECORD_AUDIO,
            //Manifest.permission.MODIFY_AUDIO_SETTINGS,
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

    protected Toolbar mTToolbar;

    private PermissionsChecker mPermissionsChecker; // 权限检测器


    private MediaPlayer mediaPlayer;
    private boolean isRecording = false;
    private TextView mTv_progress3;
    Button btn_three_play, btn_three_recorder;

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


        mPermissionsChecker = new PermissionsChecker(this);

        btn_three_play = (Button) findViewById(R.id.PlayRecordAudio_btn);
        btn_three_recorder = (Button) findViewById(R.id.StartRecordAndSave_btn);
        mTv_progress3 = (TextView) findViewById(R.id.prgress_text);

        mediaPlayer = new MediaPlayer();
        mediaPlayer.setOnCompletionListener(this);
        mediaPlayer.setOnPreparedListener(this);
        btn_three_play.setEnabled(false);

        if (mPermissionsChecker.lacksPermissions(PERMISSIONS)) {
            startPermissionsActivity();
        }

        btn_three_play.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                playRecorder();
            }
        });

        btn_three_recorder.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    recorder_Audio();  //audio权限获得
                    btn_three_play.setEnabled(true);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();

        // 缺少权限时, 进入权限配置页面
        if (mPermissionsChecker.lacksPermissions(PERMISSIONS)) {
            startPermissionsActivity();
        }
    }
    private void startPermissionsActivity() {
        PermissionsActivity.startActivityForResult(this, REQUEST_CODE, PERMISSIONS);
    }
    @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        // 拒绝时, 关闭页面, 缺少主要权限, 无法运行
        if (requestCode == REQUEST_CODE && resultCode == PermissionsActivity.PERMISSIONS_DENIED) {
            finish();
        }
    }



    private boolean isPlaying = false;
    private int frequency = 11025;
    int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
    int audiosource = MediaRecorder.AudioSource.MIC;
    int channelConfig = AudioFormat.CHANNEL_CONFIGURATION_MONO;
    File recordingFile = null;
    MainActivity.RecordAudio recordAudio = null;
    MainActivity.PlayAudio playAudio = null;

    @RequiresApi(api = Build.VERSION_CODES.CUPCAKE)
    public void recorder_Audio() throws IOException {
        //AudioRecord不会直接保存音频，需要自己保存
        Log.d("file","begin");
        File path = new File(Environment.getExternalStorageDirectory().getAbsolutePath());
        path.mkdirs();



        try {
            recordingFile = File.createTempFile("recording", ".pcm", path); //权限获得
        } catch (IOException e) {
            e.printStackTrace();
        }
        Log.d("file","end");
        recordAudio = new MainActivity.RecordAudio();
        recordAudio.execute();
    }

    public void playRecorder() {
        isRecording = false;
        playAudio = new MainActivity.PlayAudio();
        playAudio.execute();
    }


    public void onCompletion(MediaPlayer mp) {

    }


    public void onPrepared(MediaPlayer mp) {
        mediaPlayer.start();
    }

    private class PlayAudio extends AsyncTask<Void, Integer, Void> {
        @Override
        protected Void doInBackground(Void... params) {
            isPlaying = true;
            int bufferSize = AudioTrack.getMinBufferSize(frequency, channelConfig, audioFormat);
            short[] buffer = new short[bufferSize / 4];
            DataInputStream dis = null;
            try {
                dis = new DataInputStream(new BufferedInputStream(new FileInputStream(recordingFile)));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, frequency, channelConfig, audioFormat, bufferSize, AudioTrack.MODE_STREAM);
            audioTrack.play();
            try {
                while (isPlaying && dis.available() > 0) {
                    int i = 0;
                    while (dis.available() > 0 && i < buffer.length) {
                        buffer[i] = dis.readShort();
                        i++;
                    }
                    audioTrack.write(buffer, 0, buffer.length);
                }
                dis.close();

            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();

            Toast.makeText(MainActivity.this, "语音开始播放", Toast.LENGTH_SHORT).show();
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            Toast.makeText(MainActivity.this, "语音播放完了", Toast.LENGTH_SHORT).show();

        }
    }

    private class RecordAudio extends AsyncTask<Void, Integer, Void> {

        @Override
        protected Void doInBackground(Void... params) {
            isRecording = true;
            DataOutputStream dos = null;
            try {
                dos = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(recordingFile)));
                int bufferSize = AudioRecord.getMinBufferSize(frequency, channelConfig, audioFormat);
                AudioRecord audioRecord = new AudioRecord(audiosource, frequency, channelConfig, audioFormat, bufferSize);
                short[] buffer = new short[bufferSize];
                audioRecord.startRecording();
                int r = 0;
                while (isRecording) {
                    int bufferReadResult = audioRecord.read(buffer, 0, bufferSize);
                    for (int i = 0; i < bufferReadResult; i++) {
                        try {
                            dos.writeShort(buffer[i]);

                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    publishProgress(new Integer(r));
                    r++;
                }
                audioRecord.stop();
                dos.close();
            } catch (Exception e) {
                e.printStackTrace();
            }

            return null;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            Toast.makeText(MainActivity.this, "正在录音", Toast.LENGTH_SHORT).show();
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            super.onProgressUpdate(values);
            mTv_progress3.setText(values[0] + "");
        }

    }}

permissionsActivity.java

package com.example.myapplication;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.provider.Settings;

public class PermissionsActivity extends AppCompatActivity {

    public static final int PERMISSIONS_GRANTED = 0; // 权限授权
    public static final int PERMISSIONS_DENIED = 1; // 权限拒绝

    private static final int PERMISSION_REQUEST_CODE = 0; // 系统权限管理页面的参数
    private static final String EXTRA_PERMISSIONS =
            "me.chunyu.clwang.permission.extra_permission"; // 权限参数
    private static final String PACKAGE_URL_SCHEME = "package:"; // 方案

    private PermissionsChecker mChecker; // 权限检测器
    private boolean isRequireCheck; // 是否需要系统权限检测

    // 启动当前权限页面的公开接口
    public static void startActivityForResult(Activity activity, int requestCode, String... permissions) {
        Intent intent = new Intent(activity, PermissionsActivity.class);
        intent.putExtra(EXTRA_PERMISSIONS, permissions);
        ActivityCompat.startActivityForResult(activity, intent, requestCode, null);
    }

    @Override protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getIntent() == null || !getIntent().hasExtra(EXTRA_PERMISSIONS)) {
            throw new RuntimeException("PermissionsActivity需要使用静态startActivityForResult方法启动!");
        }
        setContentView(R.layout.activity_permissions);

        mChecker = new PermissionsChecker(this);
        isRequireCheck = true;
    }

    @Override protected void onResume() {
        super.onResume();
        if (isRequireCheck) {
            String[] permissions = getPermissions();
            if (mChecker.lacksPermissions(permissions)) {
                requestPermissions(permissions); // 请求权限
            } else {
                allPermissionsGranted(); // 全部权限都已获取
            }
        } else {
            isRequireCheck = true;
        }
    }

    // 返回传递的权限参数
    private String[] getPermissions() {
        return getIntent().getStringArrayExtra(EXTRA_PERMISSIONS);
    }

    // 请求权限兼容低版本
    private void requestPermissions(String... permissions) {
        ActivityCompat.requestPermissions(this, permissions, PERMISSION_REQUEST_CODE);
    }

    // 全部权限均已获取
    private void allPermissionsGranted() {
        setResult(PERMISSIONS_GRANTED);
        finish();
    }

    /**
     * 用户权限处理,
     * 如果全部获取, 则直接过.
     * 如果权限缺失, 则提示Dialog.
     *
     * @param requestCode  请求码
     * @param permissions  权限
     * @param grantResults 结果
     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == PERMISSION_REQUEST_CODE && hasAllPermissionsGranted(grantResults)) {
            isRequireCheck = true;
            allPermissionsGranted();
        } else {
            isRequireCheck = false;
            showMissingPermissionDialog();
        }
    }

    // 含有全部的权限
    private boolean hasAllPermissionsGranted(@NonNull int[] grantResults) {
        for (int grantResult : grantResults) {
            if (grantResult == PackageManager.PERMISSION_DENIED) {
                return false;
            }
        }
        return true;
    }

    // 显示缺失权限提示
    private void showMissingPermissionDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(PermissionsActivity.this);
        builder.setTitle("R.string.help");
        builder.setMessage("R.string.string_help_text");

        // 拒绝, 退出应用
        builder.setNegativeButton("R.string.quit", new DialogInterface.OnClickListener() {
            @Override public void onClick(DialogInterface dialog, int which) {
                setResult(PERMISSIONS_DENIED);
                finish();
            }
        });

        builder.setPositiveButton("R.string.settings", new DialogInterface.OnClickListener() {
            @Override public void onClick(DialogInterface dialog, int which) {
                startAppSettings();
            }
        });

        builder.show();
    }

    // 启动应用的设置
    private void startAppSettings() {
        Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
        intent.setData(Uri.parse(PACKAGE_URL_SCHEME + getPackageName()));
        startActivity(intent);
    }
}

permissionsChecker.java

package com.example.myapplication;

import android.content.Context;
import android.content.pm.PackageManager;

import androidx.core.content.ContextCompat;

public class PermissionsChecker {
    private final Context mContext;

    public PermissionsChecker(Context context) {
        mContext = context.getApplicationContext();
    }

    // 判断权限集合
    public boolean lacksPermissions(String... permissions) {
        for (String permission : permissions) {
            if (lacksPermission(permission)) {
                return true;
            }
        }
        return false;
    }

    // 判断是否缺少权限
    private boolean lacksPermission(String permission) {
        return ContextCompat.checkSelfPermission(mContext, permission) ==
                PackageManager.PERMISSION_DENIED;
    }
}