Java Utililty Methods File to Byte Array

FileInputStream is = new FileInputStream(f);
byte[] res = new byte[(int) f.length()];
is.read(res);
is.close();
return res;

FileInputStream stream = new FileInputStream(file);
try {
    long length = file.length();
    if (length > Integer.MAX_VALUE)
        throw new IOException("File too big: " + file.getName());
    int ilength = (int) length;
    byte[] bytes = new byte[ilength];
    int alength = stream.read(bytes);
...

try (FileInputStream stream = new FileInputStream(file)) {
    return readBytes(stream, (int) file.length());

if (file == null || !file.exists())
    return null;
try {
    ByteArrayOutputStream out = new ByteArrayOutputStream(4096);
    byte[] tmp = new byte[4096];
    InputStream is = new BufferedInputStream(new FileInputStream(file));
    while (true) {
        int r = is.read(tmp);
...

InputStream in = new FileInputStream(file);
int fileSize = (int) file.length();
if (fileSize > Integer.MAX_VALUE) {
    in.close();
    throw new IOException("File size to large: " + fileSize + " > " + Integer.MAX_VALUE);
byte[] bytes = new byte[fileSize];
int offset = 0;
...

if (file == null || !file.exists()) {
    return null;
ByteArrayOutputStream out = new ByteArrayOutputStream();
FileInputStream in = new FileInputStream(file);
int c = in.read();
while (c != -1) {
    out.write(c);
...

FileInputStream fileInputStream = new FileInputStream(file);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
byte[] bytes = new byte[1024];
int n = 0;
while ((n = fileInputStream.read(bytes)) != -1) {
    byteArrayOutputStream.write(bytes, 0, n);
byteArrayOutputStream.close();
...

if (!file.exists()) {
    throw new FileNotFoundException();
if (file.length() > Integer.MAX_VALUE) {
    throw new IOException("file is too large for single read");
byte[] bytes = new byte[(int) file.length()];
try (FileInputStream fileInputStream = new FileInputStream(file)) {
...

Preconditions.checkNotNull(file);
Preconditions.checkArgument(file.exists());
int size = (int) file.length();
byte[] bytes = new byte[size];
InputStream in = new FileInputStream(file);
try {
    int response = in.read(bytes);
    Preconditions.checkState(response == size);
...

InputStream is = null;
if (file.length() > Integer.MAX_VALUE)
    throw new IOException("File " + file.getAbsolutePath() + " is too large!");
byte[] bytes = new byte[(int) file.length()];
try {
    is = new FileInputStream(file);
    int curr = 0;
    int read;
...