Java Utililty Methods FileInputStream Read

return readFile(new File(filename));

String fileContents = "";
File file = new File(filename);
if (!file.exists() || !file.isFile())
    throw new IllegalArgumentException();
try (FileInputStream stream = new FileInputStream(file)) {
    byte[] fileBytes = new byte[(int) file.length()];
    stream.read(fileBytes, 0, (int) file.length());
    fileContents = new String(fileBytes);
...

FileInputStream fis = null;
ObjectInputStream ois = null;
Object o = null;
try {
    fis = new FileInputStream(DATA_DIR + filename);
    ois = new ObjectInputStream(fis);
    try {
        o = ois.readObject();
...

try {
    File file = new File(fileName);
    BufferedInputStream stream = new BufferedInputStream(new FileInputStream(file));
    byte[] bytes = new byte[(int) file.length()];
    stream.read(bytes);
    return new String(bytes);
} catch (Exception e) {
    throw new RuntimeException(e);
...

File file = new File(fileName);
return readFile(file, charset);

byte[] data = new byte[0];
FileInputStream fileInputStream = null;
try {
    File file = new File(filePath);
    fileInputStream = new FileInputStream(new File(filePath));
    data = new byte[(int) file.length()];
    fileInputStream.read(data);
} finally {
...

FileInputStream fis = new FileInputStream(new File(filePath));
byte[] bytes = new byte[fis.available()];
fis.read(bytes);
fis.close();
return bytes;

ByteArrayOutputStream baos = new ByteArrayOutputStream();
FileInputStream fis = new FileInputStream(new File(filePath));
byte[] buffer = new byte[1024];
int cant = fis.read(buffer);
while (cant > 0) {
    baos.write(buffer, 0, cant);
    cant = fis.read(buffer);
fis.close();
return baos.toByteArray();

File file = new File(filePath);
FileInputStream fin = new FileInputStream(file);
ByteArrayOutputStream bs = new ByteArrayOutputStream();
while (true) {
    int content = fin.read();
    if (content == -1) {
        String content1 = new String(bs.toByteArray(), "UTF-8");
        fin.close();
...

File infoFile = new File(filePath);
byte[] result = null;
if (infoFile.exists()) {
    result = new byte[(int) infoFile.length()];
    try {
        FileInputStream fis = new FileInputStream(infoFile);
        fis.read(result);
        fis.close();
...