FileToHex.java

/*
 * Created on 13-3-29
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 * 
 * Copyright @2013 the original author or authors.
 */
package ch18io.file;

/**
 * Description of this file.
 *
 * @author XiongNeng
 * @version 1.0
 * @since 13-3-29
 */

import java.io.*;

public class FileToHex {
    public static void convertToHex(PrintStream out, File file) throws IOException {
        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 chracater 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();
    }

    public static void main(String[] args) throws IOException {
        //display output to console
        convertToHex(System.out, new File("c:/file.txt"));

        //write the output into a file
        convertToHex(new PrintStream("c:/file.hex"), new File("c:/file.txt"));
    }
}