Initializing byte array in java

Question

I have a below snippet which works perfectly in Grrovy, now am trying to convert it to java but am getting

protected String[] extractText(byte[] fileData) {
 //Remove the BOM if present
 if (fileData.length > 3 && fileData[0..2] == [0xEF, 0xBB, 0xBF] as byte[])
 {
 fileData = fileData[3..fileData.length-1]
 }
 // method implemaentation
}

I tried changing it as below but am getting Incompatible operand types byte and byte[] compiler error

 byte[] array= { (byte)0xEF, (byte)0xBB, (byte)0xBF };
fileData.length > 3 && fileData[0..2] == array

I've never worked with byte arrays, Could anyone please help me with this?

• wypieprz: Your array variable is initialized properly. Now try to compare it with fileData. Please take look at: how to compare the Java Byte[] array?

Answer 1

I used a ByteArrayInputStream and System.arraycopy to do the job:

package bom;
import java.io.ByteArrayInputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Bom {
 public static void main(String[] args) {
 try {
 new Bom().go();
 } catch (Exception ex) {
 Logger.getLogger(Bom.class.getName()).log(Level.SEVERE, null, ex);
 }
 }
 private void go() throws Exception {
 //create data with BOM header:
 byte[] byteArrayBom = {(byte) 0xEF, (byte) 0xBB, (byte) 0xBF, 65, 66, 67};
 ByteArrayInputStream bais = new ByteArrayInputStream(byteArrayBom);
 if (byteArrayBom.length >= 3) {
 //read the first 3 bytes to detect BOM header:
 int b00 = bais.read();
 int b01 = bais.read();
 int b02 = bais.read();
 if (b00 == 239 && b01 == 187 && b02 == 191) { 
 //BOM detected. create new byte[] for bytes without BOM:
 byte[] contentWithoutBom = new byte[byteArrayBom.length - 3];
 //copy byte array without the first 3 bytes:
 System.arraycopy(byteArrayBom, 3, contentWithoutBom, 0, byteArrayBom.length - 3);
 //let's see what we have:
 System.out.println(new String(contentWithoutBom)); //ABC
 for (int i = 0; i < contentWithoutBom.length; i++) {
 System.out.println(contentWithoutBom[i]); //65, 66 67
 }
 }
 }
 }
}