dx variable name destruction

1. DecompilationTest.java

import java.util.Scanner;

public class DecompilationTest{
    public int SomeField = 123;

    public static void main(String args[]){
        DecompilationTest dt = new DecompilationTest();
        dt.SomeMethod();
    }

    public void SomeMethod(){
        System.out.print("Enter a number: ");
        Scanner in = new Scanner(System.in);

        int someInteger = in.nextInt();

        System.out.println(String.format("Your number is: %d", someInteger));
    }
}

2. Disassembly of java class

Compiled from "DecompilationTest.java"
public class DecompilationTest {
  public int SomeField;

  public DecompilationTest();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: aload_0
       5: bipush        123
       7: putfield      #2                  // Field SomeField:I
      10: return

  public static void main(java.lang.String[]);
    Code:
       0: new           #3                  // class DecompilationTest
       3: dup
       4: invokespecial #4                  // Method "<init>":()V
       7: astore_1
       8: aload_1
       9: invokevirtual #5                  // Method SomeMethod:()V
      12: return

  public void SomeMethod();
    Code:
       0: getstatic     #6                  // Field java/lang/System.out:Ljava/io/PrintStream;
       3: ldc           #7                  // String Enter a number:
       5: invokevirtual #8                  // Method java/io/PrintStream.print:(Ljava/lang/String;)V
       8: new           #9                  // class java/util/Scanner
      11: dup
      12: getstatic     #10                 // Field java/lang/System.in:Ljava/io/InputStream;
      15: invokespecial #11                 // Method java/util/Scanner."<init>":(Ljava/io/InputStream;)V
      18: astore_1
      19: aload_1
      20: invokevirtual #12                 // Method java/util/Scanner.nextInt:()I
      23: istore_2
      24: getstatic     #6                  // Field java/lang/System.out:Ljava/io/PrintStream;
      27: ldc           #13                 // String Your number is: %d
      29: iconst_1
      30: anewarray     #14                 // class java/lang/Object
      33: dup
      34: iconst_0
      35: iload_2
      36: invokestatic  #15                 // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
      39: aastore
      40: invokestatic  #16                 // Method java/lang/String.format:(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/String;
      43: invokevirtual #17                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      46: return
}

3. Disassembly of dex file

.class public LDecompilationTest;
.super Ljava/lang/Object;
.source "DecompilationTest.java"


# instance fields
.field public SomeField:I


# direct methods
.method public constructor <init>()V
    .registers 2

    .prologue
    .line 3
    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    .line 4
    const/16 v0, 0x7b

    iput v0, p0, LDecompilationTest;->SomeField:I

    return-void
.end method

.method public static main([Ljava/lang/String;)V
    .registers 2

    .prologue
    .line 7
    new-instance v0, LDecompilationTest;

    invoke-direct {v0}, LDecompilationTest;-><init>()V

    .line 8
    invoke-virtual {v0}, LDecompilationTest;->SomeMethod()V

    .line 9
    return-void
.end method


# virtual methods
.method public SomeMethod()V
    .registers 6

    .prologue
    .line 12
    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;

    const-string v1, "Enter a number: "

    invoke-virtual {v0, v1}, Ljava/io/PrintStream;->print(Ljava/lang/String;)V

    .line 13
    new-instance v0, Ljava/util/Scanner;

    sget-object v1, Ljava/lang/System;->in:Ljava/io/InputStream;

    invoke-direct {v0, v1}, Ljava/util/Scanner;-><init>(Ljava/io/InputStream;)V

    .line 15
    invoke-virtual {v0}, Ljava/util/Scanner;->nextInt()I

    move-result v0

    .line 17
    sget-object v1, Ljava/lang/System;->out:Ljava/io/PrintStream;

    const-string v2, "Your number is: %d"

    const/4 v3, 0x1

    new-array v3, v3, [Ljava/lang/Object;

    const/4 v4, 0x0

    invoke-static {v0}, Ljava/lang/Integer;->valueOf(I)Ljava/lang/Integer;

    move-result-object v0

    aput-object v0, v3, v4

    invoke-static {v2, v3}, Ljava/lang/String;->format(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/String;

    move-result-object v0

    invoke-virtual {v1, v0}, Ljava/io/PrintStream;->println(Ljava/lang/String;)V

    .line 18
    return-void
.end method

4. Decompilation of dex file

joe@satan:~/Downloads/bin$ ./jadx /tmp/demo/DecompilationTest.dex 
16:41:39 INFO  - output directory: DecompilationTest
16:41:39 INFO  - loading ...
16:41:39 INFO  - processing ...
16:41:39 INFO  - done
joe@satan:~/Downloads/bin$ cat DecompilationTest/defpackage/DecompilationTest.java 
package defpackage;

import java.util.Scanner;

public class DecompilationTest {
    public int SomeField = 123;

    public static void main(String[] strArr) {
        new DecompilationTest().SomeMethod();
    }

    public void SomeMethod() {
        System.out.print("Enter a number: ");
        int nextInt = new Scanner(System.in).nextInt();
        System.out.println(String.format("Your number is: %d", new Object[]{Integer.valueOf(nextInt)}));
    }
}

5. Strings on resulting java class file

joe@satan:/tmp/demo$ strings DecompilationTest.class 
	SomeField
<init>
Code
LineNumberTable
main
([Ljava/lang/String;)V
SomeMethod
SourceFile
DecompilationTest.java
DecompilationTest
Enter a number: 
java/util/Scanner
Your number is: %d
java/lang/Object
java/lang/System
Ljava/io/PrintStream;
java/io/PrintStream
print
(Ljava/lang/String;)V
Ljava/io/InputStream;
(Ljava/io/InputStream;)V
nextInt
java/lang/Integer
valueOf
(I)Ljava/lang/Integer;
java/lang/String
format
9(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/String;
println

6. Strings on resulting dex file

joe@satan:/tmp/demo$ strings DecompilationTest.dex
<init>
DecompilationTest.java
Enter a number: 
LDecompilationTest;
Ljava/io/InputStream;
Ljava/io/PrintStream;
Ljava/lang/Integer;
Ljava/lang/Object;
Ljava/lang/String;
Ljava/lang/System;
Ljava/util/Scanner;
	SomeField
SomeMethod
Your number is: %d
[Ljava/lang/Object;
[Ljava/lang/String;
format
main
nextInt
print
println
valueOf