Java：文件到十六进制？ [英] Java: File to Hex?

问题描述

我在Java中有一个文件

I have a file in Java

FileInputStream in = null;
try{    
in = new FileInputStream("C:\\pic.bmp");
}catch{}

我想转换 pic.bmp 到一个十六进制值的数组，所以我可以编辑并保存为修改后的版本。

I want to convert pic.bmp to an array of hex values so I can edit and save it as a modified version.

有没有一个java类可以做到这一点？

Is there a java class to do this?

推荐答案

你很幸运。几个月前我不得不这样做。这是一个从命令行获取两个参数的简化版本。两个命令行参数都是文件名......第一个是输入文件，第二个是输出文件。输入文件以二进制读取，输出文件以ASCII十六进制写入。希望您可以根据您的需要进行调整。

You're in luck. I had to do this a couple months ago. Here's a dumbed-down version that takes two parameters from the command line. Both comand line parameters are filenames...the first is the input file and the second is the output file. The input file is read in binary and the output file is written as ASCII hex. Hopefully you can just adapt this to your needs.

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;

public class BinToHex
{
    private final static String[] hexSymbols = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

    public final static int BITS_PER_HEX_DIGIT = 4;

    public static String toHexFromByte(final byte b)
    {
        byte leftSymbol = (byte)((b >>> BITS_PER_HEX_DIGIT) & 0x0f);
        byte rightSymbol = (byte)(b & 0x0f);

        return (hexSymbols[leftSymbol] + hexSymbols[rightSymbol]);
    }

    public static String toHexFromBytes(final byte[] bytes)
    {
        if(bytes == null || bytes.length == 0)
        {
            return ("");
        }

        // there are 2 hex digits per byte
        StringBuilder hexBuffer = new StringBuilder(bytes.length * 2);

        // for each byte, convert it to hex and append it to the buffer
        for(int i = 0; i < bytes.length; i++)
        {
            hexBuffer.append(toHexFromByte(bytes[i]));
        }

        return (hexBuffer.toString());
    }

    public static void main(final String[] args) throws IOException
    {
        try
        {
            FileInputStream fis = new FileInputStream(new File(args[0]));
            BufferedWriter fos = new BufferedWriter(new FileWriter(new File(args[1])));

            byte[] bytes = new byte[800];
            int value = 0;
            do
            {
                value = fis.read(bytes);
                fos.write(toHexFromBytes(bytes));

            }while(value != -1);

            fos.flush();
            fos.close();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}

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