Can't create a notification in android studio

Issue

I tried to create a notification on android to launch a foreground service. it didn't show the notification after the 'startForground' method, neither on the phone I am using nor on an emulator. so I tried to do it using a NotificationManager, it also didn't work on both of them. this is the code:

Notification.Builder notify = new Notification.Builder(this).setContentText("hello!")
            .setStyle(new Notification.BigTextStyle().bigText("sup!"))
            .setContentTitle("sup").addAction(R.drawable.ic_launcher_foreground,"hello", PendingIntent.getActivity(this, 0, new Intent(this, MainActivity.class), 0))
             .setPriority(Notification.PRIORITY_HIGH);

    if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
        notify.setSmallIcon(R.mipmap.ic_launcher);
    }else{
        notify.setSmallIcon(R.drawable.ic_launcher_foreground);
    }

    NotificationManager manager =
            (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence name = "132";
        String description = "132";
        int importance = NotificationManager.IMPORTANCE_DEFAULT;
        NotificationChannel channel = new NotificationChannel("132", name, importance);
        channel.setDescription(description);

        manager.createNotificationChannel(channel);
    }

    manager.notify(132, notify.build());

    Toast.makeText(this, "finished", Toast.LENGTH_LONG);
    setLatestAction("finished");

so, the answer was that on the version of android I was developing for, which was Oreo, you cannot show notification by normal means.

Solution

If you run your app into api 26 above like android 0 above device then need channel id.. try this code

check your app level gradle file..

apply plugin: 'com.android.application'

android {
compileSdkVersion 26
buildToolsVersion "25.0.3"
defaultConfig {
    applicationId "com.example.adruser.newnotificaion"
    minSdkVersion 20
    targetSdkVersion 26
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

  dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testCompile 'junit:junit:4.12'
}

after that project level gradle file ..

buildscript {
repositories {
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:2.3.3'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}
}

allprojects {
repositories {
    jcenter()
}
 }

 task clean(type: Delete) {
delete rootProject.buildDir
}

after that make one common notification untils class like below code..

public class NotificationUtils extends ContextWrapper {
private NotificationManager mManager;
public static String mChannel_Id = null;
public static String mChannel_Id_EX = null;

public static String group = null;

private CharSequence mChannleName = null;
private CharSequence mGroupName;
private String mDescription = "this first channel id program";
private String mDescription2 = "this second channel id";
private static final String KEY_TEXT_REPLY = "key_text_reply";

@RequiresApi(api = Build.VERSION_CODES.O)
public NotificationUtils(Context base) {
    super(base);
}

/**
 * this method create a channel.
 * this method call into a NotificationUtils class Constructor.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
public void createChannels(String channel1) {
    // create android channel
    mChannleName = channel1;// show channel mChannleName.
    NotificationChannel androidChannel = new NotificationChannel(channel1,
            mChannleName, NotificationManager.IMPORTANCE_DEFAULT);
    //mChannel_Id=channel1;
    // Sets whether notifications posted to this channel should display notification lights
    androidChannel.enableLights(true);
    androidChannel.setDescription(mDescription);
    androidChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
    // Sets whether notification posted to this channel should vibrate.
    androidChannel.enableVibration(true);
    // Sets the notification light color for notifications posted to this channel
    androidChannel.setLightColor(Color.GREEN);
    // Sets whether notifications posted to this channel appear on the lockscreen or not
    androidChannel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
    androidChannel.setShowBadge(true);
    getManager().createNotificationChannel(androidChannel);
    Toast.makeText(getApplicationContext(), "Channel created", Toast.LENGTH_SHORT).show();
}

/**
 * this method create a channel with group _id.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
public void createChannelsWithGroup(String channel1) {
    // create android channel
    mChannleName = channel1;//show channel mChannleName.
    NotificationChannel androidChannel = new NotificationChannel(channel1,
            mChannleName, NotificationManager.IMPORTANCE_DEFAULT);
    //mChannel_Id=channel1;
    // Sets whether notifications posted to this channel should display notification lights
    androidChannel.enableLights(true);
    androidChannel.setDescription(mDescription);
    androidChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
    // Sets whether notification posted to this channel should vibrate.
    androidChannel.enableVibration(true);
    // Sets the notification light color for notifications posted to this channel
    androidChannel.setLightColor(Color.GREEN);
    // Sets whether notifications posted to this channel appear on the lockscreen or not
    androidChannel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
    androidChannel.setShowBadge(true);
    androidChannel.setGroup(group);// used when create channel with group_id.
    getManager().createNotificationChannel(androidChannel);
    Toast.makeText(getApplicationContext(), "Channel created", Toast.LENGTH_SHORT).show();
    //getManager().createNotificationChannelGroup(new NotificationChannelGroup(group,mDescription));
}

/**
 * this method create a group.
 *
 * @param Group
 */
@RequiresApi(api = Build.VERSION_CODES.O)
public void createGroup(String Group) {
    mGroupName = Group;
    getManager().createNotificationChannelGroup(new NotificationChannelGroup(Group, mGroupName));
    Toast.makeText(getApplicationContext(), "Group Created", Toast.LENGTH_SHORT).show();
}

/**
 * this method define notification manager class service.
 *
 * @return
 */
@RequiresApi(api = Build.VERSION_CODES.O)
public NotificationManager getManager() {
    if (mManager == null) {
        mManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        //     mManager.createNotificationChannelGroup(new NotificationChannelGroup(group,mChannleName));
    }
    return mManager;
}

@RequiresApi(api = Build.VERSION_CODES.O)
public Notification.Builder getAndroidChannelNotification(String title, String body) {
    return new Notification.Builder(getApplicationContext(), mChannel_Id)
            .setContentTitle(title)
            .setContentText(body)
            .setChannelId(mChannel_Id)
            .setSmallIcon(android.R.drawable.stat_notify_more)
            .setAutoCancel(true);
}

/**
 * this method create a simple notification useing channel id.
 *
 * @param message
 * @return
 */
@RequiresApi(api = Build.VERSION_CODES.O)
public Notification.Builder createNotification(String message) {
    Intent resultIntent = new Intent(this, ResultActivity.class);
    resultIntent.putExtra("message", message);
    TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
    stackBuilder.addParentStack(ResultActivity.class);
    stackBuilder.addNextIntent(resultIntent);
    PendingIntent resultPendingIntent =
            stackBuilder.getPendingIntent(
                    0,
                    PendingIntent.FLAG_UPDATE_CURRENT
            );

    return new Notification.Builder(getApplicationContext(), mChannel_Id)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle(mChannel_Id)
            .setContentText(message)
            //.setGroup(group)
            .setChannelId(mChannel_Id)
            .setContentIntent(resultPendingIntent);
}

/**
 * this method used create a Expand_Notification.
 *
 * @param message
 * @return
 */
@RequiresApi(api = Build.VERSION_CODES.O)
public Notification.Builder longNotficationMessage(String message) {

    Notification.InboxStyle inboxStyle =
            new Notification.InboxStyle();
    String[] events = new String[6];
    inboxStyle.setBigContentTitle("Event tracker details:");
    for (int i = 0; i < events.length; i++) {
        events[i] = "Hii how";
        inboxStyle.addLine(events[i]);
    }
    Intent resultIntent = new Intent(this, ResultActivity.class);
    resultIntent.putExtra("message", message);
    TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
    stackBuilder.addParentStack(ResultActivity.class);
    stackBuilder.addNextIntent(resultIntent);
    PendingIntent resultPendingIntent =
            stackBuilder.getPendingIntent(
                    0,
                    PendingIntent.FLAG_UPDATE_CURRENT
            );
    return new Notification.Builder(getApplicationContext(), mChannel_Id_EX)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle(mChannel_Id_EX)
            .setContentText(message)
            //.setGroup(group)
            .setChannelId(mChannel_Id_EX)
            .setStyle(inboxStyle)
            .setAutoCancel(true)
            .setContentIntent(resultPendingIntent);
}

/**
 * this method used to show group of notification.
 */
public void showStackNotifications() {
    Bitmap bitmapMila = BitmapFactory.decodeResource(getResources(), R.drawable.placeholder_border);

    // Nuke all previous notifications and generate unique ids
    NotificationManagerCompat.from(this).cancelAll();
    int notificationId = 0;


    // Group notification that will be visible on the phone
    Notification summaryNotification = new NotificationCompat.Builder(this)
            .setContentTitle("2 Pet Notifications")
            .setContentText("nilay and Dylan both sent messages")
            .setSmallIcon(R.mipmap.ic_launcher)
            .setLargeIcon(bitmapMila)
            .setGroup(group)
            .setGroupSummary(true)
            .build();

    // Separate notifications that will be visible on the watch
    Intent viewIntent1 = new Intent(this, MainActivity.class);
    PendingIntent viewPendingIntent1 =
            PendingIntent.getActivity(this, notificationId + 1, viewIntent1, 0);
    Notification notification1 = new NotificationCompat.Builder(this)
            .addAction(R.mipmap.ic_launcher, "Treat Fed", viewPendingIntent1)
            .setContentTitle("Message from nilay")
            .setContentText("What's for dinner? "
                    + "Can we have steak?")

            .setSmallIcon(R.mipmap.ic_launcher)
            .setGroup(group)
            .build();

    Intent viewIntent2 = new Intent(this, MainActivity.class);
    PendingIntent viewPendingIntent2 =
            PendingIntent.getActivity(this, notificationId + 2, viewIntent2, 0);
    Notification notification2 = new NotificationCompat.Builder(this)
            .addAction(R.mipmap.ic_launcher_round, "Water Filled", viewPendingIntent2)
            .setContentTitle("Message from Dylan")
            .setContentText("Can you refill our water bowl?")
            .setSmallIcon(R.drawable.placeholder_border)
            .setGroup(group)
            .build();

    // Issue the group notification
    NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
    notificationManager.notify(notificationId + 0, summaryNotification);

    // Issue the separate wear notifications
    notificationManager.notify(notificationId + 2, notification2);
    notificationManager.notify(notificationId + 1, notification1);
}
}

after that call notification in activity..

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
private NotificationUtils mNotificationUtils;
private final int mNotification_Id=101;
private static final String KEY_TEXT_REPLY = "key_text_reply";
private EditText mEtChannel1, mEtChannel2,mEtGroupName;
private Button mBtnCreateChannel,mBtnDialog,mBtnSettings,mBtnGroupChannel,mBtnGroupNotification,mBtnExpandLayout,mBtnReplay,mBtndelete,mBtnGroup;
private int mImportance;
private Notification.Builder mBuilder;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        initView();
        setListener();
    }
}

/**
 * this method used to set listener on view controls.
 */
private void setListener()
{
    mBtnDialog.setOnClickListener(this);
    mBtnCreateChannel.setOnClickListener(this);
    mBtnSettings.setOnClickListener(this);
    mBtnExpandLayout.setOnClickListener(this);
    mBtnReplay.setOnClickListener(this);
    mBtndelete.setOnClickListener(this);
    mBtnGroupChannel.setOnClickListener(this);
    mBtnGroupNotification.setOnClickListener(this);
    mBtnGroup.setOnClickListener(this);
}

/**
 * this method initialized view controls.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void initView() {
    mNotificationUtils = new NotificationUtils(this);
    mEtChannel1 = (EditText) findViewById(R.id.amEtChannel1);
    mEtChannel2 = (EditText) findViewById(R.id.amEtChannel2);
    mEtGroupName = (EditText) findViewById(R.id.amEtGroupName);
    mBtnCreateChannel = (Button) findViewById(R.id.amBtnChannel);
    mBtnGroup= (Button) findViewById(R.id.amBtnGroup);
    mBtnDialog= (Button) findViewById(R.id.amBtnDialog);
    mBtnSettings= (Button) findViewById(R.id.amBtnSetting);
    mBtnExpandLayout= (Button) findViewById(R.id.amBtnExpandLayout);
    mBtnReplay= (Button) findViewById(R.id.amBtnReplay);
    mBtndelete= (Button) findViewById(R.id.amBtnDeleteChannel);
    mBtnGroupChannel= (Button) findViewById(R.id.amBtnGroupChannel);
    mBtnGroupNotification= (Button) findViewById(R.id.amBtnGroupNotification);
}

@RequiresApi(api = Build.VERSION_CODES.O)
@Override
public void onClick(View view) {
    switch (view.getId())
    {
        case R.id.amBtnChannel:
          createChannle();
            //setNotification();
            showNotificationDialog();
            break;

        case R.id.amBtnGroup:
                createGroup();
            break;
        case R.id.amBtnDialog:
            if (TextUtils.isEmpty(mNotificationUtils.mChannel_Id))
            {
                Toast.makeText(getApplicationContext(),"First Create a Notification Channel",Toast.LENGTH_SHORT).show();
            }
            else {
                showNotificationDialog();
            }
            break;
        case R.id.amBtnSetting:
            openSettiongs();
            break;

        case R.id.amBtnExpandLayout:
            expandLayoutNotification();
            break;

        case R.id.amBtnGroupChannel:
            createGroupChannel();
            break;

        case R.id.amBtnReplay:
            replayNotification("Hii Hello");
            break;
        case R.id.amBtnDeleteChannel:
            deleteChannelId();
            break;
        case R.id.amBtnGroupNotification:
            mNotificationUtils.showStackNotifications();
            break;
    }
}

/**
 * this method create two channel.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void createChannle() {
    if(!TextUtils.isEmpty(mEtChannel1.getText().toString().trim())) {
        mNotificationUtils = new NotificationUtils(this);
        mNotificationUtils.createChannels(mEtChannel1.getText().toString().trim());
        mNotificationUtils.mChannel_Id=mEtChannel1.getText().toString().trim();
        mEtChannel1.setText("");
    }
    if (!TextUtils.isEmpty(mEtChannel2.getText().toString().trim()))
    {
        mNotificationUtils = new NotificationUtils(this);
        mNotificationUtils.createChannels( mEtChannel2.getText().toString().trim());
        mNotificationUtils.mChannel_Id_EX=mEtChannel2.getText().toString().trim();
        mEtChannel2.setText("");
    }
    else
    {
        Toast.makeText(getApplicationContext(),"Name is Empty",Toast.LENGTH_SHORT).show();
    }
}

/**
 * this method create group of channel.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void createGroupChannel() {
    if (!TextUtils.isEmpty(mEtChannel1.getText().toString().trim())) {
        mNotificationUtils = new NotificationUtils(this);
        mNotificationUtils.createChannelsWithGroup(mEtChannel1.getText().toString().trim());
        mEtChannel1.setText("");
    }
}
/**
 * this method make a group.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void createGroup() {
    mNotificationUtils = new NotificationUtils(this);
    if (!TextUtils.isEmpty(mEtGroupName.getText().toString().trim())) {
        mNotificationUtils.createGroup(mEtGroupName.getText().toString().trim());
        mNotificationUtils.group=mEtGroupName.getText().toString().trim();
    }
    else
    {
        Toast.makeText(getApplicationContext(),"Plase Enter Group Name",Toast.LENGTH_SHORT).show();
    }
}

/**
 * this method delete channel_Id.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void deleteChannelId() {
    NotificationManager mNotificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    mNotificationManager.deleteNotificationChannel(NotificationUtils.mChannel_Id);
}

/**
 * this method call expand_layout notification.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void expandLayoutNotification() {
    mBuilder =mNotificationUtils.longNotficationMessage("Who are you");
    mNotificationUtils.getManager().notify(mNotification_Id, mBuilder.build());
}

/**
 * this method used to open setting or read notification channel settings.
 */
private void openSettiongs() {
    Intent i = new Intent(Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS);
    i.putExtra(Settings.EXTRA_APP_PACKAGE, getPackageName());
    i.putExtra(Settings.EXTRA_CHANNEL_ID, NotificationUtils.mChannel_Id);
    i.putExtra(Settings.EXTRA_CHANNEL_ID, NotificationUtils.mChannel_Id_EX);
    startActivity(i);
}

/**
 * this method call simple notification and also calling NotificationUtils class createNotification method.
 */
private void showNotificationDialog() {
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
        mBuilder = mNotificationUtils.createNotification("Hii how are you");
        mNotificationUtils.getManager().notify(mNotification_Id, mBuilder.build());
    }
}

/**
 * this method set notification.
 */
@RequiresApi(api = Build.VERSION_CODES.O)
private void setNotification() {
    String username = mEtChannel1.getText().toString().trim();
    String password = mEtChannel2.getText().toString().trim();

    if(!TextUtils.isEmpty(username) && !TextUtils.isEmpty(password)) {
        mBuilder = mNotificationUtils.
                getAndroidChannelNotification(username, "By " + password);
        mNotificationUtils.getManager().notify(mNotification_Id, mBuilder.build());
    }
}

/**
 * this method create a inline replay notification.
 * @param message
 */
@RequiresApi(api = Build.VERSION_CODES.KITKAT_WATCH)
private void replayNotification(String message)
{
    if(!TextUtils.isEmpty(mNotificationUtils.mChannel_Id)) {
        String replyLabel = getResources().getString(R.string.label);
        RemoteInput remoteInput = new RemoteInput.Builder(KEY_TEXT_REPLY)
                .setLabel(replyLabel)
                .build();

        Intent resultIntent = new Intent(this, ResultActivity.class);
        PendingIntent replyPendingIntent = PendingIntent.getActivity(this, (int) System.currentTimeMillis(), resultIntent, 0);

        Notification.Action action = new Notification.Action.Builder(R.mipmap.ic_launcher_round,
                getString(R.string.reply_label), replyPendingIntent)
                .addRemoteInput(remoteInput)
                .build();
        Notification.Action cancleAction = new Notification.Action.Builder(R.mipmap.ic_launcher, "Cancle", replyPendingIntent).build();

        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.placeholder_border);
        Notification newMessageNotification =
                new Notification.Builder(getApplicationContext())
                        .setSmallIcon(R.mipmap.ic_launcher)
                        .setContentTitle(getString(R.string.title))
                        .setContentText(message)
                        .setAutoCancel(true)
                        .setLargeIcon(bitmap)
                        .setChannelId(NotificationUtils.mChannel_Id)
                        .addAction(action)
                        .addAction(cancleAction)
                        .build();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            //mBuilder=mNotificationUtils.replayNotification(message);
            mNotificationUtils.getManager().notify(mNotification_Id, newMessageNotification);
        }
    }
    else
    {
        Toast.makeText(getApplicationContext(),"Create Notification Channel",Toast.LENGTH_LONG).show();
    }
}
}

above define all things notification

Answered By - Mobile Team ADR-Flutter