[LANG-1719] RandomStringUtils.random outputs strings that are equal over and over

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.13.0
• Fix Version/s: 3.15.0
• Component/s: lang.*

Environment

Samsung Smartphone

Product name: Galaxy A53 5G

Model name: SM-A536B/DS

Software info:

One UI version 5.1

Android version 13

• Assignee: Gary D. Gregory
• Reporter: Benjamin Glatzeder
• Created: 19/Nov/23 08:59
• Updated: 12/Aug/24 14:00
• Resolved: 22/Jul/24 11:28

Description

The following line of code outputs equal strings over and over:

RandomStringUtils.random(12,"abcdefghijklmnopqrstuvwxyz0123456789") 

Steps to reproduce:
1) Create a new Android project in Android Studio
2) Add the following dependency to your gradle file

implementation("org.apache.commons:commons-lang3:3.13.0") 

3) Use the following code in your MainActivity:

package test.randomstringutils

import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity
import org.apache.commons.lang3.RandomStringUtils

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState : Bundle?) {
        super.onCreate(savedInstanceState)
        val randomString = RandomStringUtils.random(12,"abcdefghijklmnopqrstuvwxyz0123456789")
        Log.d(TAG, randomString)
    }

    companion object {
        private const val TAG = "TAG"
    }
}

4) Run project and note the string in Logcat
5) Run project again and compare the new random string in Logcat

One will note that the strings are equal. The expected result should be that the strings are not equal. Here's an example output:

09:33:10.154 TAG                  tes...tringutils  D  m9mcx5ywuxdc
09:33:28.561 TAG                  tes...tringutils  D  m9mcx5ywuxdc

Using the previous commons-lang3 version in the project resolves the issue. Here are the steps to reproduce:
1) Replace

implementation("org.apache.commons:commons-lang3:3.13.0") 

with

implementation("org.apache.commons:commons-lang3:3.12.0") 

2) Click on "Sync now"
3) Run project and note the string in Logcat
4) Run project again and compare the new random string in Logcat

One will note that the strings are not equal. This is the expected result. Here's an example output:

09:40:50.268 TAG                  tes...tringutils  D  1tjkvkta6ibi
09:40:55.324 TAG                  tes...tringutils  D  02nfvrf9pfgl

 

I was able to consistently reproduce this issue using a Samsung Galaxy A53 5G smartphone as well as on an Android Virtual Device (AVD). To the best of my knowledge the smartphone runs on an ARM processor and the AVD has an emulated ARM processor.

I was not able to reproduce this issue when I created a Kotlin project in IntelliJ with similar lines of code which was running on my Windows machine with an x64 processor.