Android: Simple Password Generator

[preinix]

In this tutorial we will try to create a Simple Password Generator Using Android. Android is most commonly comes installed on a variety of smartphones and tablets, and even in TV. Android is an open source so that developer find it easy to develop and expand new features. So let's do the coding...

Getting Started:

First you will have to download & install the Android Development IDE (Android Studio or Eclipse). Android Studio is an open source development feel free to develop your things.

Here's the link for the Android Studio https://developer.android.com/studio/index.html.

Layout Design

We will now add some layout to the application. Just kindly copy the code below and paste it inside the code editor

1. <?
   
   xml version=
   
   "1.0"
   
   encoding=
   
   "utf-8"
   
   ?>
   
2. <
   
   RelativeLayout xmlns:
   
   android=
   
   "http://schemas.android.com/apk/res/android"
   
3. xmlns:
   
   app=
   
   "http://schemas.android.com/apk/res-auto"
   
4. xmlns:
   
   tools=
   
   "http://schemas.android.com/tools"
   
5. android:
   
   layout_width=
   
   "match_parent"
   
6. android:
   
   layout_height=
   
   "match_parent"
   
7. tools:
   
   context=
   
   "com.razormist.simplepaswordgenerator.MainActivity"
   
   >
   
8. 
   
9. <
   
   TextView
   
10. android:
    
    id=
    
    "@+id/tv_password"
    
11. android:
    
    layout_width=
    
    "match_parent"
    
12. android:
    
    layout_height=
    
    "wrap_content"
    
13. android:
    
    fontFamily=
    
    "monospace"
    
14. android:
    
    textSize=
    
    "40sp"
    
15. android:
    
    gravity=
    
    "center"
    
16. android:
    
    layout_centerInParent=
    
    "true"
    
17. android:
    
    layout_marginBottom=
    
    "40dp"
    
18. android:
    
    hint=
    
    "Password"
    
    />
    
19. <
    
    Button
    
    
    
20. android:
    
    id=
    
    "@+id/btn_generate"
    
21. android:
    
    layout_width=
    
    "wrap_content"
    
22. android:
    
    layout_height=
    
    "wrap_content"
    
23. android:
    
    layout_centerInParent=
    
    "true"
    
24. android:
    
    layout_below=
    
    "@+id/tv_password"
    
25. android:
    
    text=
    
    "Generate"
    
    />
    
26. 
    
27. </
    
    RelativeLayout>
    

Android Manifest File

The Android Manifest file provides essential information about your app to the Android system in which the system must required before running the code.

1. <?
   
   xml version=
   
   "1.0"
   
   encoding=
   
   "utf-8"
   
   ?>
   
2. <
   
   manifest xmlns:
   
   android=
   
   "http://schemas.android.com/apk/res/android"
   
3. package
   
   =
   
   "com.razormist.simplepaswordgenerator"
   
   >
   
4. 
   
5. <
   
   application
   
6. android:
   
   allowBackup=
   
   "true"
   
7. android:
   
   icon=
   
   "@mipmap/ic_launcher"
   
8. android:
   
   label=
   
   "@string/app_name"
   
9. android:
   
   roundIcon=
   
   "@mipmap/ic_launcher_round"
   
10. android:
    
    supportsRtl=
    
    "true"
    
11. android:
    
    theme=
    
    "@Style/AppTheme"
    
    >
    
12. <
    
    activity android:
    
    name=
    
    ".MainActivity"
    
13. android:
    
    configChanges=
    
    "orientation"
    
14. android:
    
    screenOrientation=
    
    "portrait"
    
    >
    
15. <
    
    intent-
    
    filter>
    
16. <
    
    action android:
    
    name=
    
    "android.intent.action.MAIN"
    
    />
    
17. 
    
18. <
    
    category android:
    
    name=
    
    "android.intent.category.LAUNCHER"
    
    />
    
19. </
    
    intent-
    
    filter>
    
20. </
    
    activity>
    
21. </
    
    application>
    
22. 
    
23. </
    
    manifest>
    

The Main Function

This code contains the main function of the application. This code will randomly display a certain character the generate button is clicked.

1. package
   
   com.razormist.simplepaswordgenerator
   
   ;
   
2. 
   
3. import
   
   android.support.v7.app.AppCompatActivity
   
   ;
   
4. import
   
   android.os.Bundle
   
   ;
   
5. import
   
   android.view.View
   
   ;
   
6. import
   
   android.widget.Button
   
   ;
   
7. import
   
   android.widget.TextView
   
   ;
   
8. 
   
9. import
   
   java.util.Random
   
   ;
   
10. 
    
11. public
    
    class
    
    MainActivity extends
    
    AppCompatActivity {
    
12. 
    
13. TextView tv_passowrd;
    
14. Button
    
    btn_generate;
    
15. 
    
16. @Override
    
17. protected
    
    void
    
    onCreate(
    
    Bundle savedInstanceState)
    
    {
    
18. super
    
    .onCreate
    
    (
    
    savedInstanceState)
    
    ;
    
19. setContentView(
    
    R.layout
    
    .activity_main
    
    )
    
    ;
    
20. 
    
21. tv_passowrd =
    
    (
    
    TextView)
    
    findViewById(
    
    R.id
    
    .tv_password
    
    )
    
    ;
    
22. btn_generate =
    
    (
    
    Button
    
    )
    
    findViewById(
    
    R.id
    
    .btn_generate
    
    )
    
    ;
    
23. 
    
24. 
    
25. btn_generate.setOnClickListener
    
    (
    
    new
    
    View
    
    .OnClickListener
    
    (
    
    )
    
    {
    
26. @Override
    
27. public
    
    void
    
    onClick(
    
    View
    
    v)
    
    {
    
28. int
    
    length =
    
    12
    
    ;
    
29. 
    
30. tv_passowrd.setText
    
    (
    
    GetPassword(
    
    length)
    
    )
    
    ;
    
31. 
    
32. }
    
33. }
    
    )
    
    ;
    
34. 
    
35. }
    
36. 
    
37. public
    
    String
    
    GetPassword(
    
    int
    
    length)
    
    {
    
38. char
    
    [
    
    ]
    
    chars =
    
    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
    
    .toCharArray
    
    (
    
    )
    
    ;
    
39. StringBuilder stringBuilder =
    
    new
    
    StringBuilder(
    
    )
    
    ;
    
40. 
    
41. Random
    
    rand =
    
    new
    
    Random
    
    (
    
    )
    
    ;
    
42. 
    
43. for
    
    (
    
    int
    
    i =
    
    0
    
    ;
    
    i <
    
    length;
    
    i++
    
    )
    
    {
    
44. char
    
    c =
    
    chars[
    
    rand.nextInt
    
    (
    
    chars.length
    
    )
    
    ]
    
    ;
    
45. stringBuilder.append
    
    (
    
    c)
    
    ;
    
46. }
    
47. 
    
48. return
    
    stringBuilder.toString
    
    (
    
    )
    
    ;
    
49. }
    
50. }
    

There you have it we successfully created a Simple Password Generator using Android. I hope that this simple tutorial help you to your projects. For more updates and tutorials just kindly visit this site. Enjoy Coding!!

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