Java - File length() Method



Description

The Java File length() returns the length of the file defined by this abstract pathname. The return value is unspecified if this pathname defines a directory.

Declaration

Following is the declaration for java.io.File.length() method −

public long length()

Parameters

NA

Return Value

The method returns length, in bytes, of the file denoted by this abstract pathname.

Exception

SecurityException − If a security manager exists and its SecurityManager.checkRead(java.lang.String) method denies read access to the file

Example 1

The following example shows the usage of Java File length() method. We've created two File references. Then we're creating a File Object using test.txt which is not present in the current directory. Then we've created the file using createNewFile() method. Now using getAbsoluteFile() method, we're getting the file and getting the file length using length() method and printing it.

package com.tutorialspoint;
import java.io.File;
public class FileDemo {
   public static void main(String[] args) {      
      File f = null;
      File f1 = null;
      
      try {
         // create new files
         f = new File("test.txt");
         
         // create new file in the system
         f.createNewFile();
         
         // create new file object from the absolute path
         f1 = f.getAbsoluteFile();
         
         // prints the file length
         System.out.print("File length: "+ f1.length());
         
      } catch(Exception e) {
         // if any error occurs
         e.printStackTrace();
      }
   }
}

Output

Let us compile and run the above program, this will produce the following result −

File length: 0

Example 2

The following example shows the usage of Java File length() method. We've created a File reference. Then we're creating a File Object using F:/test1.txt which is present in the provided directory but is hidden. Now using getAbsoluteFile() method, we're getting the file and printing file length using length() method.

package com.tutorialspoint;
import java.io.File;
public class FileDemo {
   public static void main(String[] args) {      
      File f = null;
      
      try {
         // create new files
         f = new File("F:/test1.txt");         
    
         // get the file
         File f1 = f.getAbsoluteFile();
         
         // prints the file length
         System.out.println("File length: "+f1.length());
         
      } catch(Exception e) {
         // if any error occurs
         e.printStackTrace();
      }
   }
}

Output

Let us compile and run the above program, this will produce the following result −. We're assuming that test.txt contains following content −

This is a sample file.

The output will be as follows −

File length: 22

Example 3

The following example shows the usage of Java File length() method. We've created a File reference. Then we're creating a File Object using F:/test directory which is present in the provided location and is not hidden. Now using getAbsoluteFile() method, we're getting the directory and its length using length() method.

package com.tutorialspoint;
import java.io.File;
public class FileDemo {
   public static void main(String[] args) {      
      File f = null;     
      try {
         
         // create new files
         f = new File("F:/test");         
    
         // get the file
         File f1 = f.getAbsoluteFile();
         
         // prints the directory length
         System.out.println("Directory length: "+f1.length());
         
      } catch(Exception e) {
         // if any error occurs
         e.printStackTrace();
      }
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Directory length: 4096
java_file_class.htm
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