HexReader.java

package utilities;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;

public class HexReader {

	public static String readEofTag(File file) throws IOException {
		// This method does not work at all
		String eofTag = null;

		InputStream is = new FileInputStream(file);
		int value = 0;

		StringBuilder sbHex = new StringBuilder();
		StringBuilder sbText = new StringBuilder();

		if ((value = is.read()) == -1) {
			// convert to hex value with "X" formatter
			sbHex.append(String.format("%02X ", value));
			// If the character is not convertable, just print a dot symbol "."
			if (!Character.isISOControl(value)) {
				sbText.append((char) value);
			} else {
				sbText.append(".");
			}
		}
		is.close();
		eofTag = sbText.toString();
		return eofTag;
	}

	public static void convertToHex(PrintWriter out, File file) throws IOException {

		/*
		 * TODO: tests show that only the first part of the file is
		 * read/converted. The rest is missing
		 */
		InputStream is = new FileInputStream(file);

		int bytesCounter = 0;
		int value = 0;
		StringBuilder sbHex = new StringBuilder();
		StringBuilder sbText = new StringBuilder();
		StringBuilder sbResult = new StringBuilder();

		while ((value = is.read()) != -1) {
			// convert to hex value with "X" formatter
			sbHex.append(String.format("%02X ", value));

			// If the character is not convertable, just print a dot symbol "."
			if (!Character.isISOControl(value)) {
				sbText.append((char) value);
			} else {
				sbText.append(".");
			}

			// if 16 bytes are read, reset the counter,
			// clear the StringBuilder for formatting purpose only.
			if (bytesCounter == 15) {
				sbResult.append(sbHex).append("      ").append(sbText).append("\n");
				sbHex.setLength(0);
				sbText.setLength(0);
				bytesCounter = 0;
			} else {
				bytesCounter++;
			}
		}

		// if still got content
		if (bytesCounter != 0) {
			// add spaces more formatting purpose only
			for (; bytesCounter < 16; bytesCounter++) {
				// 1 character 3 spaces
				sbHex.append("   ");
			}
			sbResult.append(sbHex).append("      ").append(sbText).append("\n");
		}

		out.print(sbResult);
		is.close();
	}

}