The document provides code for building a basic Android app with Java. It includes XML layout files and Java code for activities to display buttons, lists, forms and spinners. XML files define the user interface for a main activity with buttons, a form activity, spinner activity and listview activity. Corresponding Java classes set onClick listeners for buttons to start activities, populate and respond to selections in spinners and lists. The code provides a basic framework to build an introductory Android app.

1. Basic APP Android Java
persiapan awal membuat xml :
1. activity_main.xml
2. activity_form.xml
3. activity_spinner.xml
4. activity_listview.xml
persiapan membuat java :
1. SpinnerActivity.java
2. FormActivity.java
3. ListviewActivity.java
4. MainActivity.java

2. coding activity_main.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:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<Button
android:id="@+id/bToast"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button Toast"
tools:ignore="MissingConstraints" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bListView"
android:text="Halaman ListView"
tools:ignore="MissingConstraints" />
<Button
android:id="@+id/bspinner"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Spinner" />
<Button
android:id="@+id/bform"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Page Form" />
<Button
android:id="@+id/bexit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Exit" />
</LinearLayout>
coding MainActivity.java
package com.example.myapplication;
import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;

3. import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity implements
OnClickListener {
Button b1, b2, b3, b4, b5;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1 = (Button) findViewById(R.id.bToast);
b2 =(Button) findViewById(R.id.bListView);
b3 = (Button) findViewById(R.id.bspinner);
b4 = (Button) findViewById(R.id.bform);
b5 = (Button) findViewById(R.id.bexit);
b1.setOnClickListener(this);
b2.setOnClickListener(this);
b3.setOnClickListener(this);
b4.setOnClickListener(this);
b5.setOnClickListener(this);
}
@SuppressLint("ResourceType")
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.layout.activity_main, menu);
return true;
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.bToast:
Toast.makeText(this, "This is Notification",
Toast.LENGTH_SHORT).show();
break;
case R.id.bListView:
Intent b = new Intent(MainActivity.this,
ListViewActivity.class);
startActivity(b);
break;
case R.id.bform:
Intent f = new Intent(MainActivity.this,
FormActivity.class);
startActivity(f);
break;
case R.id.bspinner:
Intent s = new Intent(MainActivity.this,
SpinnerActivity.class);
startActivity(s);

4. break;
case R.id.bexit:
// Toast.makeText(this, "Button Exit",
Toast.LENGTH_SHORT).show();
ShowExitDialog();
break;
}
}
private void ShowExitDialog(){
//TODO Auto-generated method stub
AlertDialog.Builder ad = new AlertDialog.Builder(this);
ad.setTitle("Warning");
ad.setMessage("are You sure exit from apps ?");
ad.setPositiveButton("yes", new
DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface,
int which) {
MainActivity.this.finish();
}
});
ad.setNegativeButton("no", new
DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface,
int which) {
//TODO Auto-generated method stub
dialogInterface.dismiss();
}
});
ad.show();
}
}
output :

5. Coding activity_form.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:stretchColumns="1">

6. <TableRow
android:id="@+id/tableRows"
android:layout_height="wrap_content"
android:layout_width="wrap_content">
<TextView
android:id="@+id/textView1"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="Username"
/>
<EditText
android:id="@+id/inUser"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="username here">
<requestFocus/>
</EditText>
</TableRow>
<TableRow>
<TextView
android:id="@+id/inpassword"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="Password"/>
<EditText
android:id="@+id/inPass"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="password in here"/>
</TableRow>
</TableLayout>
<Button
android:id="@+id/bLogin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="login"/>
</LinearLayout>
Coding FormActivity.java
package com.example.myapplication;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

7. import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.Nullable;
public class FormActivity extends Activity {
EditText username, pass;
Button blogin;
String user_name= "user";
String password = "user123";
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_form);
username = (EditText) findViewById(R.id.inUser);
pass = (EditText) findViewById(R.id.inPass);
blogin = (Button) findViewById(R.id.bLogin);
blogin.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String u = username.getText().toString();
String p = pass.getText().toString();
checkLogin(u, p);
}
});
}
private void checkLogin(String u, String p) {
if(p.equals(password) && u.equals(user_name)){
Toast.makeText(this, "Login Success",
Toast.LENGTH_SHORT).show();
Intent intent = new Intent(FormActivity.this,
MainActivity.class);
startActivity(intent);
this.finish();
} else{
Toast.makeText(this, "Login Failled",
Toast.LENGTH_SHORT).show();
}
}
}

8. output :
Coding activity_spinner.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Spinner
android:id="@+id/idSpinner"
android:layout_width="match_parent"

9. android:layout_height="wrap_content"/>
</LinearLayout>
Coding SpinnerActivity.java
package com.example.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import androidx.annotation.Nullable;
public class SpinnerActivity extends Activity {
Spinner sp;
String[] item ={"nasi goreng","mie ayam","nasi uduk","pecel
lele","Magelangan","Soto ayam"};
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_spinner);
sp = (Spinner)findViewById(R.id.idSpinner);
ArrayAdapter<String> array_item = new
ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, item);
sp.setAdapter(array_item);
sp.setOnItemSelectedListener(new
AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View
arg1, int arg2, long arg3) {
Toast.makeText(SpinnerActivity.this, "Kamu
Memilih" +
item[arg2],Toast.LENGTH_SHORT).show();
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
Toast.makeText(SpinnerActivity.this,
"Nothing Selected",
Toast.LENGTH_SHORT).show();
}
});
}
}

10. output
Coding activity_listview.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"

11. android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/idListView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
Coding ListViewActivity.java
package com.example.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Toast;
import android.widget.ListView;
import androidx.annotation.Nullable;
import java.util.List;
public class ListViewActivity extends Activity {
ListView lv;
String[] item = {"Nasi Goreng","Mie Goreng", "Mie
Ayam","Magelangan",
"Soto Ayam","Sop Ayam","Ayam Goreng"};
@Override
protected void onCreate( Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_listview);
lv = (ListView) findViewById(R.id.idListView);
ArrayAdapter<String> array_item = new
ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, item);
lv.setAdapter(array_item);
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View
arg1, int arg2, long arg3) {
Toast.makeText(ListViewActivity.this,
"Kamu Memilih" + item[arg2],
Toast.LENGTH_SHORT).show();
}
});
}
}

12. output :
@TerimaKasih
Herry Prasetyo
2019