Javaでファイルを16進数に変換する方法

package com.mkyong;

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

public class File2Hex
{
    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"));
    }
}

デモ

ダミーコンテンツを含むファイル

ABCDEFG
12345678
[email protected]#$%^&** ()
Testing only

上記のクラスで処理された後、次のHex値が表示されます:

41 42 43 44 45 46 47 0D 0A 31 32 33 34 35 36 37       ABCDEFG..1234567
38 0D 0A 21 40 23 24 25 5E 26 2A 28 29 0D 0A 54       [email protected]#$%^&** ()..T
65 73 74 69 6E 67 20 6F 6E 6C 79                      esting only

リファレンス

リンク://タグ/ファイル/[ファイル]リンク://タグ/16進数/[16進]リンク://タグ/io/[io]リンク://タグ/java/[java]

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