Java Android App Development Course, Job Scheduler

1. Introduction

In modern society, time management is a very important factor. Reflecting this need,
we will develop an app that allows users to manage their schedules and
conveniently schedule jobs using the Android platform.
This course focuses on creating Android apps using Java.

2. Job Scheduler App Overview

The job scheduler app provides users with the ability to add, modify, and delete schedules.
Users can easily receive notifications about schedule changes.
This course will be centered around implementing these basic features.

  • Key Features:
  • Add and delete schedules
  • Modify schedules
  • Notification feature
  • User Interface (UI) design

3. Setting Up the Development Environment

To develop Android apps, you need to set up a few tools and libraries.
Typically, Android Studio, JDK, and Gradle are required.
Below are the necessary tools.

  • Android Studio: Official IDE for Android development
  • Java Development Kit (JDK): Tools for compiling and running Java
  • Gradle: Dependency management and build tool

After installing Android Studio, create a new project.

4. Creating the Project and Basic Setup

Open Android Studio and create a new project.
Select ‘Empty Activity’ and enter the project name and package name.
Click ‘Finish’ to create the project.

5. UI Design

The user interface of the job scheduler needs to be designed.
Use XML to define the UI. Below is a simple layout example.


            <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/titleTextView"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Job Scheduler"
                    android:textSize="24sp"/>

                <EditText
                    android:id="@+id/jobEditText"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="Please enter a schedule"/>

                <Button
                    android:id="@+id/addButton"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Add"/>

                <ListView
                    android:id="@+id/jobListView"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"/>

            </LinearLayout>
        

6. Implementing Business Logic

Now that the UI is implemented, we need to implement the business logic.
We will write methods to handle user input and add and delete schedules.


            public class MainActivity extends AppCompatActivity {
                private EditText jobEditText;
                private Button addButton;
                private ListView jobListView;
                private ArrayAdapter<String> adapter;
                private ArrayList<String> jobList;

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

                    jobEditText = findViewById(R.id.jobEditText);
                    addButton = findViewById(R.id.addButton);
                    jobListView = findViewById(R.id.jobListView);
                    jobList = new ArrayList<>();

                    adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, jobList);
                    jobListView.setAdapter(adapter);

                    addButton.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            String job = jobEditText.getText().toString();
                            if (!job.isEmpty()) {
                                jobList.add(job);
                                adapter.notifyDataSetChanged();
                                jobEditText.setText("");
                            }
                        }
                    });
                }
            }
        

7. Implementing Notification Feature

After adding the schedule, we will implement the notification feature.
We will use AlarmManager to send notifications. Here is an example of the notification feature implementation.


            private void setAlarm(long triggerAtMillis) {
                AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
                Intent intent = new Intent(this, AlarmReceiver.class);
                PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
                alarmManager.setExact(AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent);
            }
        

8. Deployment and Testing of the App

Once the app’s functionality is complete, you need to test it on various devices and
prepare to distribute it on Google Play.
To deploy, you need to go through the app signing and build process.

9. Conclusion

Through this course, we learned how to develop an Android job scheduler app using Java.
I hope it helped enhance your understanding of Android app development as you added each feature.
By creating a real app, may you gain more experience and reference materials to further improve.