How to round long number and show it as string in android?

Question

Hi I have a list of files. I want to show file length of each file. I create own method for getting file length and right unit(base value).

Source

public String getFileLength(long lengthBytes){
    Log.i("", 1 + " -- FILE INFO -- " + lengthBytes);
    String lengthString;
    if(lengthBytes<1024){
        Log.i("", 21 + " -- FILE INFO B -- " + lengthBytes);
        lengthString = lengthBytes + " B";
        Log.i("", 22 + " -- FILE INFO B -- " + lengthString);
    } else if (lengthBytes<(1024^2)){
        Log.i("", 31 + " -- FILE INFO KB -- " + lengthBytes);
        //length = String.valueOf(Math.round(i/1024)) + " KB";
        lengthString = lengthBytes/1024 + " KB";
        Log.i("", 32 + " -- FILE INFO KB -- " + lengthString);
    } else if (lengthBytes<(1024^3)){
        Log.i("", 41 + " -- FILE INFO MB -- " + lengthBytes);
        lengthString = lengthBytes/(1024^2) + " MB";
        Log.i("", 42 + " -- FILE INFO MB -- " + lengthBytes);
    } else if (lengthBytes<(1024^4)){
        Log.i("", 51 + " -- FILE INFO GB -- " + lengthBytes);
        lengthString = lengthBytes / (1024 ^ 3) + " GB";
        Log.i("", 52 + " -- FILE INFO GB -- " + lengthBytes);
    } else lengthString = "ERR";

    return lengthString;
}

It shows me in application ERR. I want to debug it so I added a lot of Log.i. What logcat shows me you can see under this sentence.

Logcat shows me this:

06-30 11:50:23.523    1590-1590/info.myapplication15.app I/﹕ 1 -- FILE INFO -- 292303
06-30 11:50:24.253    1590-1590/info.myapplication15.app D/dalvikvm﹕ GC_FOR_ALLOC freed 99K, 5% free 3268K/3436K, paused 58ms, total 65ms
06-30 11:50:24.263    1590-1590/info.myapplication15.app I/dalvikvm-heap﹕ Grow heap (frag case) to 4.330MB for 1127536-byte allocation
06-30 11:50:24.443    1590-1599/info.myapplication15.app D/dalvikvm﹕ GC_FOR_ALLOC freed 6K, 4% free 4362K/4540K, paused 95ms, total 95ms
06-30 11:50:25.503    1590-1590/info.myapplication15.app W/Resources﹕ Converting to string: TypedValue{t=0x12/d=0x0 a=2 r=0x7f070040}
06-30 11:50:25.563    1590-1590/info.myapplication15.app W/Resources﹕ Converting to string: TypedValue{t=0x12/d=0x0 a=2 r=0x7f070041}
06-30 11:50:25.683    1590-1590/info.myapplication15.app W/Resources﹕ Converting to string: TypedValue{t=0x12/d=0x0 a=2 r=0x7f070042}
06-30 11:50:26.103    1590-1590/info.myapplication15.app W/Resources﹕ Converting to string: TypedValue{t=0x12/d=0x0 a=2 r=0x7f070040}
06-30 11:50:26.143    1590-1590/info.myapplication15.app W/Resources﹕ Converting to string: TypedValue{t=0x12/d=0x0 a=2 r=0x7f070041}
06-30 11:50:26.223    1590-1590/info.myapplication15.app W/Resources﹕ Converting to string: TypedValue{t=0x12/d=0x0 a=2 r=0x7f070042}
06-30 11:50:26.753    1590-1590/info.myapplication15.app I/Choreographer﹕ Skipped 180 frames!  The application may be doing too much work on its main thread.

And I want to show string with round number and unit. I read that I should use Math.round(i/1024)

I want (File length is 292303) to show: 285.45 KB

After a quick search, I found this: http://stackoverflow.com/questions/3758606/how-to-convert-byte-size-into-human-readable-format-in-java — OrhanC1, Jun 30 '14 at 16:32

score 1 · Accepted Answer · edited May 23 '17 at 11:57

1

just use the code below:

  public String round(long unrounded) {
    BigDecimal bd = new BigDecimal(unrounded);
    BigDecimal rounded = bd.setScale(1, BigDecimal.ROUND_CEILING);
    return String.valueOf(rounded.longValue()) ;
  }

OR just use Math.ceil() instead of round()..

EDIT:Just use the accepted answer from this link which i provided below..

public static String humanReadableByteCount(long bytes, boolean si) {
 int unit = si ? 1000 : 1024;
 if (bytes < unit) return bytes + " B";
 int exp = (int) (Math.log(bytes) / Math.log(unit));
 String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp-1) + (si ? "" : "i");
 return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
}

edited May 23 '17 at 11:57

Community

1
1

answered Jun 30 '14 at 16:08

Ranjit

5,130
3
30
66

1

after if it doesnt show me my variable... i dont know why... and I wrote what I want. I want to show string with round number and unit (B, KB, MB, GB, ...). – Thomas Edifice Jun 30 '14 at 16:17
just use math.ceil() insted of round().. and check is it helpful for you..\ – Ranjit Jun 30 '14 at 16:28
you think something like this: `lengthBytes = lengthBytes/1024; lengthString = Math.ceil(lengthBytes) + " KB";` – Thomas Edifice Jun 30 '14 at 16:35
check this link..may be it will help you..http://stackoverflow.com/questions/153724/how-to-round-a-number-to-n-decimal-places-in-java – Ranjit Jun 30 '14 at 16:36
maybe I have bug somewhere else? Did you check whole code that i wrote? – Thomas Edifice Jun 30 '14 at 16:37
i think..you have to check the link as OrhanC1 suggested..http://stackoverflow.com/questions/3758606/how-to-convert-byte-size-into-human-readable-format-in-java – Ranjit Jun 30 '14 at 16:42
bug will be there: `if(lengthBytes<1024){` but what is bad with this – Thomas Edifice Jun 30 '14 at 16:44
yes this code is helpful for me... it solve my problems... thank you – Thomas Edifice Jun 30 '14 at 16:47

How to round long number and show it as string in android?

1 Answers1