Java Utililty Methods Is Text File

try {
    byte[] buf = new byte[512];
    FileInputStream in = new FileInputStream(file);
    int len = in.read(buf);
    in.close();
    if (len == 0)
        return true;
    int numNonTextChars = 0;
...

try (BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream(file))) {
    int count = 0;
    int val = bufferedInputStream.read();
    while ((count < MAX_NB_BINARY_BYTES) && (val >= 0)) {
        if (val == 0) {
            return false;
        count++;
...

if (!f.isFile()) {
    return false;
final String name = f.getName();
final int lastDotIdx = name.lastIndexOf('.');
if (lastDotIdx < 0) {
    return false;
final String extension = name.substring(lastDotIdx + 1);
switch (extension) {
case "buildinfo":
case "html":
case "css":
case "js":
case "svg":
case "txt":
case "xml":
    return true;
case "map":
    return name.endsWith(".css.map") || name.endsWith(".js.map");
return false;

if (!f.isFile())
    return false;
BufferedReader br = null;
try {
    FileReader fr = new FileReader(f);
    br = new BufferedReader(fr);
    int l = (int) f.length();
    if (l > length)
...

boolean check = false;
String fileName = file.getName();
int lastDot = fileName.lastIndexOf('.');
if (lastDot != -1) {
    String extension = fileName.substring(lastDot + 1);
    check = asciiFileExtensions.contains(extension);
return check;
...

return isTextFile(file, 1024);