package com.coderising.jvm.loader;
import java.util.Arrays;
import com.coderising.jvm.util.Util;
public class ByteCodeIterator {
byte[] codes;
int pos = 0;
public ByteCodeIterator(byte[] codes) {
this.codes = codes;
}
public String nextU4ToHexString() {
return Util.byteToHexString(new byte[]{codes[pos++],codes[pos++],codes[pos++],codes[pos++]});
}
public int nextU1ToInt() {
return Util.byteToInt(new byte[]{codes[pos++]});
}
public int nextU2ToInt() {
return Util.byteToInt(new byte[]{codes[pos++],codes[pos++]});
}
public int nextU4ToInt() {
return Util.byteToInt(new byte[]{codes[pos++],codes[pos++],codes[pos++],codes[pos++]});
}
public byte[] getBytes(int length) {
if(pos + length >= codes.length){
throw new ArrayIndexOutOfBoundsException();
}
byte[] data = Arrays.copyOfRange(codes, pos, pos+length);
pos = pos + length;
return data;
}
public String nextUxToHexString(int len) {
byte[] temp = new byte[len];
for(int i = 0; i < len; i++){
temp[i] = codes[pos++];
}
return Util.byteToHexString(temp).toLowerCase();
}
public void back(int i) {
pos -= i;
}
}