Java Utililty Methods File to Byte Array

ByteArrayOutputStream ous = null;
InputStream ios = null;
try {
    byte[] buffer = new byte[BYTE_BUFFER];
    ous = new ByteArrayOutputStream();
    ios = new FileInputStream(file);
    int read = 0;
    while ((read = ios.read(buffer)) != -1) {
...

byte[] res = null;
try {
    File f = new File(file);
    FileInputStream fin = new FileInputStream(f);
    res = new byte[fin.available()];
    int b = fin.read(res);
    if (b != res.length) {
        return null;
...

File f = new File(filename);
if (!f.exists()) {
    throw new FileNotFoundException(filename);
ByteArrayOutputStream bos = new ByteArrayOutputStream((int) f.length());
BufferedInputStream in = null;
try {
    in = new BufferedInputStream(new FileInputStream(f));
...

File f = new File(filename);
long len = f.length();
if (len >= (1L << 32))
    throw new RuntimeException("File " + filename + " is larger than 2^32 bytes: " + len);
BufferedInputStream is = new BufferedInputStream(new FileInputStream(f));
int int_len = (int) len;
byte b[] = new byte[int_len];
int totalBytesRead = 0;
...

byte[] result = null;
try {
    ByteArrayOutputStream bos = new ByteArrayOutputStream(2048);
    byte[] buff = new byte[2048];
    FileInputStream fis = new FileInputStream(fileName);
    while (true) {
        int len = fis.read(buff);
        if (len == -1) {
...

File f = new File(filename);
byte[] bytes = null;
if (f.exists()) {
    try {
        bytes = getBytesFromFile(f);
    } catch (Exception e) {
        System.out.println("getBytesFromFile() exception: " + e);
return bytes;

File file = new File(filepath);
InputStream is = new FileInputStream(file);
long length = file.length();
byte[] bytes = new byte[(int) length];
int offset = 0;
int numRead = 0;
while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
    offset += numRead;
...

return getBytesFromFile(new File(filePath));

FileInputStream inputStream = null;
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try {
    inputStream = new FileInputStream(file);
    int read = 0;
    byte[] buffer = new byte[4096];
    while ((read = inputStream.read(buffer)) != -1) {
        outputStream.write(buffer, 0, read);
...