Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

public class Main {
    /**
     * Retrieves the value from the byte array for the tag value specified. The
     * array should be of the form Tag - Length - Value triplet.
     * @param tag the tag to retrieve from the byte array
     * @param triplet the byte sequence containing the tag length value form
     * @return the value of the specified tag
     */
    public static byte[] getTagValue(byte tag, byte[] triplet) {

        int index = findTag(tag, triplet);
        if (index == -1) {
            return null;
        }

        index++;
        int length = triplet[index] & 0xFF;

        byte[] result = new byte[length];
        index++;
        System.arraycopy(triplet, index, result, 0, length);

        return result;
    }

    /**
     * Finds the index that starts the tag value pair in the byte array provide.
     * @param tag the tag to look for
     * @param value the byte array to search
     * @return the starting index of the tag or -1 if the tag could not be found
     */
    public static int findTag(byte tag, byte[] value) {
        int length = 0;

        if (value == null) {
            return -1;
        }

        int index = 0;

        while ((index < value.length) && (value[index] != tag)) {
            length = value[index + 1] & 0xFF;
            index += length + 2;
        }

        if (index >= value.length) {
            return -1;
        }

        return index;
    }
}