MainActivity.java

package com.example.alarmpart;

import androidx.appcompat.app.AppCompatActivity;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.media.AudioManager;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.TimePicker;

import java.util.Calendar;
import java.util.Date;


public class MainActivity extends AppCompatActivity {

    TimePicker timePicker;
    TextView textView;
    int mHour,mMin;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        timePicker = (TimePicker)findViewById(R.id.timePicker);
        textView = (TextView)findViewById(R.id.timetext);
        Button mute = (Button) findViewById(R.id.mute);





        mute.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getApplicationContext(),ttt_part.class);
                startActivity(intent);
            }
        });

        timePicker.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
            @Override
            public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {
                  mHour= hourOfDay;
                  mMin= minute;
                  textView.setText(textView.getText().toString());
            }
        });

    }

    public void setTimer(View v){

        AlarmManager alarmManager= (AlarmManager)getSystemService(Context.ALARM_SERVICE);

        Date date = new Date();

        Calendar cal_alarm = Calendar.getInstance();
        Calendar cal_now = Calendar.getInstance();

        cal_now.setTime(date);
        cal_alarm.setTime(date);

        cal_alarm.set(Calendar.HOUR_OF_DAY,mHour);
        cal_alarm.set(Calendar.MINUTE,mMin);
        cal_alarm.set(Calendar.SECOND,0);

        if(cal_alarm.before(cal_now)){

            cal_alarm.add(Calendar.DATE,1);
        }

        Intent i = new Intent(MainActivity.this,MyBroadcastReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(MainActivity.this,24444,i,0);
        alarmManager.set(AlarmManager.RTC_WAKEUP,cal_alarm.getTimeInMillis(),pendingIntent);





    }

    public void muter(){
        final AudioManager audioManager = (AudioManager) getSystemService(getApplicationContext().AUDIO_SERVICE);
        audioManager.setRingerMode(AudioManager.RINGER_MODE_SILENT);

    }

}