How to get the size of a file in MB (Megabytes)?

Question

I have a zip file on a server.

How can I check if the file size is larger than 27 MB?

File file = new File("U:\intranet_root\intranet\R1112B2.zip");
if (file > 27) {
   //do something
}

Here you get readable file size formatting... http://stackoverflow.com/a/5599842/2408621 — DocFoster, Jul 25 '13 at 10:37

score 180 · Accepted Answer · answered Jan 24 '12 at 16:00

Use the length() method of the File class to return the size of the file in bytes.

// Get file from file name
File file = new File("U:\intranet_root\intranet\R1112B2.zip");

// Get length of file in bytes
long fileSizeInBytes = file.length();
// Convert the bytes to Kilobytes (1 KB = 1024 Bytes)
long fileSizeInKB = fileSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
long fileSizeInMB = fileSizeInKB / 1024;

if (fileSizeInMB > 27) {
  ...
}

You could combine the conversion into one step, but I've tried to fully illustrate the process.

https://jsfiddle.net/darkkyoun/3g71k6ho/16/ I did a fiddle base on your code, so whoever need it, can use the fiddle to test it out — yongchang, Apr 23 '21 at 01:54

score 52 · Answer 2 · edited Jan 24 '12 at 15:57

52

Try following code:

File file = new File("infilename");

// Get the number of bytes in the file
long sizeInBytes = file.length();
//transform in MB
long sizeInMb = sizeInBytes / (1024 * 1024);

edited Jan 24 '12 at 15:57

Radu Murzea

10,424
10
46
69

answered Jan 24 '12 at 15:51

endian

4,681
7
31
54

score 45 · Answer 3 · edited Feb 11 '19 at 13:01

45

Example :

public static String getStringSizeLengthFile(long size) {

    DecimalFormat df = new DecimalFormat("0.00");

    float sizeKb = 1024.0f;
    float sizeMb = sizeKb * sizeKb;
    float sizeGb = sizeMb * sizeKb;
    float sizeTerra = sizeGb * sizeKb;


    if(size < sizeMb)
        return df.format(size / sizeKb)+ " Kb";
    else if(size < sizeGb)
        return df.format(size / sizeMb) + " Mb";
    else if(size < sizeTerra)
        return df.format(size / sizeGb) + " Gb";

    return "";
}

edited Feb 11 '19 at 13:01

Dunedan

6,813
6
38
47

answered Mar 15 '14 at 15:34

Nicolas

4,263
3
18
19

1

Lots of unneeded stuff being done, but I guess it's easier for a newbie to understand. – Buffalo May 22 '19 at 07:10

score 15 · Answer 4 · answered Feb 15 '17 at 14:54

Easiest is by using FileUtils from Apache commons-io.( https://commons.apache.org/proper/commons-io/javadocs/api-2.5/org/apache/commons/io/FileUtils.html )

Returns human readable file size from Bytes to Exabytes , rounding down to the boundary.

File fileObj = new File(filePathString);
String fileSizeReadable = FileUtils.byteCountToDisplaySize(fileObj.length());

// output will be like 56 MB

score 12 · Answer 5 · answered Jan 24 '12 at 15:52

12

file.length() will return you the length in bytes, then you divide that by 1048576, and now you've got megabytes!

answered Jan 24 '12 at 15:52

Luciano

8,402
5
30
56

7

Thanks for this multiplication, This saves me from writing (1024*1024), saved 4 keystrokes!! :D – TapanHP Jan 17 '18 at 15:02

ROMANIA_engineer · Answer 6 · 2016-06-10T09:42:46.740

Since Java 7 you can use java.nio.file.Files.size(Path p).

Path path = Paths.get("C:\\1.txt");

long expectedSizeInMB = 27;
long expectedSizeInBytes = 1024 * 1024 * expectedSizeInMB;

long sizeInBytes = -1;
try {
    sizeInBytes = Files.size(path);
} catch (IOException e) {
    System.err.println("Cannot get the size - " + e);
    return;
}

if (sizeInBytes > expectedSizeInBytes) {
    System.out.println("Bigger than " + expectedSizeInMB + " MB");
} else {
    System.out.println("Not bigger than " + expectedSizeInMB + " MB");
}

score 4 · Answer 7 · answered Jan 24 '12 at 15:53

4

You can retrieve the length of the file with File#length(), which will return a value in bytes, so you need to divide this by 1024*1024 to get its value in mb.

answered Jan 24 '12 at 15:53

Kingamajick

2,247
1
16
19

score 2 · Answer 8 · answered Jan 22 '20 at 18:47

Kotlin Extension Solution

Add these somewhere, then call if (myFile.sizeInMb > 27.0) or whichever you need:

val File.size get() = if (!exists()) 0.0 else length().toDouble()
val File.sizeInKb get() = size / 1024
val File.sizeInMb get() = sizeInKb / 1024
val File.sizeInGb get() = sizeInMb / 1024
val File.sizeInTb get() = sizeInGb / 1024

If you'd like to make working with a String or Uri easier, try adding these:

fun Uri.asFile(): File = File(toString())

fun String?.asUri(): Uri? {
    try {
        return Uri.parse(this)
    } catch (e: Exception) {
    }
    return null
}

If you'd like to easily display the values as a string, these are simple wrappers. Feel free to customize the default decimals displayed

fun File.sizeStr(): String = size.toString()
fun File.sizeStrInKb(decimals: Int = 0): String = "%.${decimals}f".format(sizeInKb)
fun File.sizeStrInMb(decimals: Int = 0): String = "%.${decimals}f".format(sizeInMb)
fun File.sizeStrInGb(decimals: Int = 0): String = "%.${decimals}f".format(sizeInGb)

fun File.sizeStrWithBytes(): String = sizeStr() + "b"
fun File.sizeStrWithKb(decimals: Int = 0): String = sizeStrInKb(decimals) + "Kb"
fun File.sizeStrWithMb(decimals: Int = 0): String = sizeStrInMb(decimals) + "Mb"
fun File.sizeStrWithGb(decimals: Int = 0): String = sizeStrInGb(decimals) + "Gb"

score 0 · Answer 9 · answered Nov 03 '13 at 06:10

0

public static long sizeOf(File file)

More info on API : http://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/FileUtils.html

answered Nov 03 '13 at 06:10

Balaji Boggaram Ramanarayan

6,419
5
37
43

This method returns File (or directory) size in *bytes*, not in megabytes: http://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/FileUtils.html#sizeOf(java.io.File). In order to get size in megabytes, you still need to divide by 1024 twice. – Scadge May 14 '15 at 10:44

score 0 · Answer 10 · answered Apr 18 '17 at 06:38

You can use substring to get portio of String which is equal to 1 mb:

public static void main(String[] args) {
        // Get length of String in bytes
        String string = "long string";
        long sizeInBytes = string.getBytes().length;
        int oneMb=1024*1024;
        if (sizeInBytes>oneMb) {
          String string1Mb=string.substring(0, oneMb);
        }
    }

score 0 · Answer 11 · answered Nov 11 '19 at 07:55

You can use FileChannel in Java.

FileChannel has the size() method to determine the size of the file.

    String fileName = "D://words.txt";

    Path filePath = Paths.get(fileName);

    FileChannel fileChannel = FileChannel.open(filePath);
    long fileSize = fileChannel.size();

    System.out.format("The size of the file: %d bytes", fileSize);

Or you can determine the file size using Apache Commons' FileUtils' sizeOf() method. If you are using maven, add this to pom.xml file.

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.6</version>
</dependency>

Try the following coding,

    String fileName = "D://words.txt";
    File f = new File(fileName);

    long fileSize = FileUtils.sizeOf(f);        

    System.out.format("The size of the file: %d bytes", fileSize);

These methods will output the size in Bytes. So to get the MB size, you need to divide the file size from (1024*1024).

Now you can simply use the if-else conditions since the size is captured in MB.

score 0 · Answer 12 · answered Jun 05 '20 at 06:42

     String FILE_NAME = "C:\\Ajay\\TEST\\data_996KB.json";
     File file = new File(FILE_NAME);

    if((file.length()) <= (1048576)) {      
        System.out.println("file size is less than 1 mb");
        }else {
            System.out.println("file size is More  than 1 mb");             
        }

Note: 1048576= (1024*1024)=1MB output : file size is less than 1 mb

score 0 · Answer 13 · edited Feb 09 '22 at 15:55

You can do something like this:

public static String getSizeLabel(Integer size) {

    String cnt_size = "0";
    double size_kb = size / 1024;
    double size_mb = size_kb / 1024;
    double size_gb = size_mb / 1024;

    if (Math.floor(size_gb) > 0) {
        try {
            String[] snplit = String.valueOf((size_gb)).split("\\.");
            cnt_size = snplit[0] + "." + snplit[1].substring(0, 2) + "GB";
        } catch (Exception e) {

            cnt_size = String.valueOf(Math.round(size_gb)) + "GB";
        }
    } else if (Math.floor(size_mb) > 0) {
        try {
            String[] snplit = String.valueOf((size_mb)).split("\\.");
            cnt_size = snplit[0] + "." + snplit[1].substring(0, 2) + "MB";

        } catch (Exception e) {

            cnt_size = String.valueOf(Math.round(size_mb)) + "MB";
        }
    } else {
        cnt_size = String.valueOf(Math.round(size_kb)) + "KB";
    }

    return cnt_size;
}

How To use:

Integer filesize = new File("path").length();
getSizeLabel(filesize) // Output  16.02MB

How to get the size of a file in MB (Megabytes)?

13 Answers13

Kotlin Extension Solution

Linked