Byte order mark screws up file reading in Java

Question

I\'m trying to read CSV files using Java. Some of the files may have a byte order mark in the beginning, but not all. When present, the byte order gets read along with the r

Answer 1

NotePad++ is a good tool to convert UTF-8 encoding to UTF-8(BOM) encoding.

https://notepad-plus-plus.org/downloads/

UTF8BOMTester.java

public class UTF8BOMTester {

public static void main(String[] args) throws FileNotFoundException, IOException {
    // TODO Auto-generated method stub
    File file = new File("test.txt");
    boolean same = UTF8BOMInputStream.isSameEncodingType(file);
    System.out.println(same);
    if (same) {
        UTF8BOMInputStream is = new UTF8BOMInputStream(file);
        BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
        System.out.println(br.readLine());
    }

}

static void bytesPrint(byte[] b) {
    for (byte a : b)
        System.out.printf("%x ", a);
}}

UTF8BOMInputStream.java

public class UTF8BOMInputStream extends InputStream {

byte[] SYMBLE_BOM = { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF };
FileInputStream fis;
final boolean isSameEncodingType;
public UTF8BOMInputStream(File file) throws IOException {
    FileInputStream fis=new FileInputStream(file);
    byte[] symble=new byte[3];
    fis.read(symble);
    bytesPrint(symble);
    isSameEncodingType=isSameEncodingType(symble);
    if(isSameEncodingType)
        this.fis=fis;
    else
        this.fis=null;
    
}

@Override
public int read() throws IOException {
    return fis.read();
}

void bytesPrint(byte[] b) {
    for (byte a : b)
        System.out.printf("%x ", a);
}

boolean bytesCompare(byte[] a, byte[] b) {
    if (a.length != b.length)
        return false;

    for (int i = 0; i < a.length; i++) {
        if (a[i] != b[i])
            return false;
    }
    return true;
}
boolean isSameEncodingType(byte[] symble) {
    return bytesCompare(symble,SYMBLE_BOM);
}
public static boolean isSameEncodingType(File file) throws IOException {
    return (new UTF8BOMInputStream(file)).isSameEncodingType;
}