On this document we will be showing a java example on how to use the length() method of File Class. This method returns the length of the file denoted by this abstract pathname. The return value is unspecified if this pathname denotes a directory.

Where it is required to distinguish an I/O exception from the case that 0L is returned, or where several attributes of the same file are required at the same time, then the Files.readAttributes method may be used.


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

Method Syntax

public long length()

Method Argument

Data Type Parameter Description

Method Returns

This method returns a long, which denotes the length, in bytes, of the file denoted by this abstract pathname, or 0L if the file does not exist. Some operating systems may return 0L for pathnames denoting system-dependent entities such as devices or pipes.


Requires Java 1.0 and up

Java File length() Example

Below is a java code demonstrates the use of length() method of File class. The example presented might be simple however it shows the behaviour of the length() method of File class. The return value of lastModified() method is a long which we have printed on the console.

Sample Output

Below is the sample output when you run the above example.

java lang File length() example output

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