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.xtt暗号化アルゴリズムを実行していますが、Javaでのファイルの書き込みと読み取りに関してサポートが必要です。暗号化の一環として、基本的にBase64でエンコードされたバイトを.txtファイルに書き込み、これらの正確なバイトを読み取り、デコードして、復号化プロセスを実行するために使用する必要があります。

.txtファイルに書き込んでいるものとは異なるものを読んでいるようです。基本的に、ファイルに書き込んでいるバイト配列をチェックすると、次のように読み取られます[B@56e5b723が、ファイルを読み取ると、が生成され[B@35a8767ます。

これが私のJavaコンソールに出力された結果です。

***Numbs converted to ByteArray is as follows: [B@56e5b723
Size of NumbsByteArray is: 10

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-x-x-x-x-x WriteByteArrayToFile(byte[] encoded) HAS STARTED -x-x-x-x-x

6,7,8,9,10 has been received as a byte array in WriteByteArrayToFile(byte[] encoded): [B@56e5b723

6,7,8,9,10 IS TO BE WRITTEN TO THE FILE: /Users/anmonari/Desktop/textfiletwo.txt

bs.write(encoded); HAS BEEN CALLED

-x-x-x-x-x WriteByteArrayToFile(byte[] encoded) HAS ENDED -x-x-x-x-x

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-x-x-x-x-x ReadByteArray() HAS STARTED -x-x-x-x-x

fileData read as bytes is: [B@35a8767

Size of fileData is: 10

fileDataString when converted to a string using String object is����������

fileDataString when converted to a string using fileDataStringTwo.toString()[B@35a8767

fileDataString.getBytes(); is: [B@2c6f7ce9

-x-x-x-x-x ReadByteArray() HAS ENDED -x-x-x-x-x***

以下は私のコードです：

package com.writeandreadfromfile;

import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class WriteAndRead {

    public static void main(String j[]) {

        String Numbs = "6,7,8,9,10";

        byte[] NumbsByteArray = Numbs.getBytes();

        System.out.println("Numbs converted to ByteArray is as follows: " + NumbsByteArray);
        System.out.println("Size of NumbsByteArray is: " + NumbsByteArray.length);

        System.out.println("\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");

        WriteByteArrayToFile(NumbsByteArray);

        System.out.println("\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");

        try {
            ReadByteArrayFromFile();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    // Write ByteArray To File
    public static void WriteByteArrayToFile(byte[] NumbsByteArray) {
        System.out.println("\n-x-x-x-x-x WriteByteArrayToFile(byte[] encoded) HAS STARTED -x-x-x-x-x");

        System.out.println("6,7,8,9,10 has been received as a byte array in WriteByteArrayToFile(byte[] encoded): " + NumbsByteArray);

        String fileName = "/Users/anmonari/Desktop/textfiletwo.txt";

        System.out.println("6,7,8,9,10 IS TO BE WRITTEN TO THE FILE: " + fileName);

        BufferedOutputStream bs = null;

        try {

            FileOutputStream fs = new FileOutputStream(new File(fileName));
            bs = new BufferedOutputStream(fs);
            bs.write(NumbsByteArray);
            System.out.println("bs.write(encoded); HAS BEEN CALLED");
            bs.close();
            bs = null;

        } catch (Exception e) {
            e.printStackTrace();
        }

        if (bs != null) try { bs.close(); } catch (Exception e) {}

        System.out.println("-x-x-x-x-x WriteByteArrayToFile(byte[] encoded) HAS ENDED -x-x-x-x-x");
    }

    // Read ByteArray To File
    public static void ReadByteArrayFromFile() throws IOException {
        // Create FileInputStream and feed it the file name
        System.out.println("-x-x-x-x-x ReadByteArray() HAS STARTED -x-x-x-x-x");

        File file;

        try {
            file = new File("/Users/anmonari/Desktop/textfiletwo.txt");

            // Create the object of DataInputStream
            DataInputStream in = new DataInputStream((new FileInputStream(file)));

            byte[] fileData = new byte[(int)file.length()];

            System.out.println("fileData read as bytes is from file: "  + fileData);

            System.out.println("Size of fileData is: " + fileData.length);

            //String fileDataString = in.readLine();

            String fileDataString = new String(fileData);
            System.out.println("fileDataString when converted to a string using String object is"  + fileDataString);

            String fileDataStringTwo = fileData.toString();
            System.out.println("fileDataString when converted to a string using fileDataStringTwo.toString()" + fileDataStringTwo);

            fileDataString.getBytes();
            System.out.println("fileDataString.getBytes(); is: "  + fileDataString.getBytes());

            //Close the input stream
            in.close();

        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        System.out.println("-x-x-x-x-x ReadByteArray() HAS ENDED -x-x-x-x-x");

    }
}

Any assistance regarding how to read from a file the exact byte array you wrote onto a file is appreciated!

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3 に答える 3

1

You're not printing the contents of the byte arrays. You're outputting their type and hashCode (the result of the toString() method on arrays).

To output the contents of a byte array, use

System.out.println(java.util.Arrays.toString(array));
于 2013-03-11T21:12:42.683 に答える
0

You can try bs(fs).flush() which buffered everything which were written out

于 2013-03-11T21:14:27.950 に答える
0

In addition to what Sotirios pointed out (you're not reading from in), you're writing the byte array as text, i.e. "6,7,8,9,10", but then you're calling fileDataString.getBytes();. That gets the bytes of the string, which (assuming UTF-8) will be 0x36 0x2c 0x37 0x2c 0x38 0x2c 0x39 0x2c 0x31 0x30.

If your plan is that the file will be text, you need to parse the string back into a byte array. Maybe something like

String[] numbers = fileDataString.split();
byte[] bytes = new byte[numbers.length];
for (int i = 0; i < numbers.length; i++) {
    bytes[i] = Byte.parseByte(numbers[i]);
}

On the other hand, if you just need to save and restore byte arrays, you'll have a simpler time with just an ObjectOutputStream and ObjectInputStream.

于 2013-03-11T21:27:59.577 に答える