de.marcreichelt.webp_backport

Class FileSignatureChecker

java.lang.Object

de.marcreichelt.webp_backport.FileSignatureChecker

public class FileSignatureChecker
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
FileSignatureChecker()

Method Summary

Modifier and Type	Method and Description
static boolean	checkForRIFF(byte[] data) Check if a given byte array has a signature that starts with 'RIFF'
static boolean	checkForWebP(byte[] image) Check if a given byte array has the necessary WebP signature in the beginning of its content.
static boolean	containsAt(byte[] haystack, byte[] needle, int offset) Check if a byte array contains another byte array that is equal or smaller in size
static boolean	startsWith(byte[] haystack, byte[] needle) Check if a byte array starts with the same bytes as another byte array that is however smaller than the first one.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileSignatureChecker

public FileSignatureChecker()

Method Detail

checkForWebP

public static boolean checkForWebP(byte[] image)

Check if a given byte array has the necessary WebP signature in the beginning of its content. The signature is 'RIFFxxxxWEBP' where 'xxxx' is the file size.

Parameters:

image - the byte array to check

Returns:

true if the byte array has the WebP signature else false

checkForRIFF

public static boolean checkForRIFF(byte[] data)

Check if a given byte array has a signature that starts with 'RIFF'

Parameters:

data - the byte array to check

Returns:

true if the byte array starts with RIFF else false

startsWith

public static boolean startsWith(byte[] haystack,
                                 byte[] needle)

Check if a byte array starts with the same bytes as another byte array that is however smaller than the first one.

Parameters:

haystack - e.g. {-1, -40, -1, -32, ........}

needle - e.g. {-1, -40, -1, -32}

Returns:

true if haystack starts with the same bytes as needle

containsAt

public static boolean containsAt(byte[] haystack,
                                 byte[] needle,
                                 int offset)

Check if a byte array contains another byte array that is equal or smaller in size

Parameters:

haystack - e.g. {..., -1, -40, -1, -32, ...}

needle - e.g. {-1, -40, -1, -32}

offset - the index where needle should be starting in haystack

Returns:

true if needle is contained in haystack starting at index offset