测试简单的Java加密/解密inputFileName不存在

Question

此代码在每个字符后添加数字100

import java.io.*;
import java.io.IOException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class FileEncryptionAndDecryption {
    public static void main(String[] args)
    throws IOException {
        String inputFileName = "DemoFile";
        String encryptedFile = "Encrypted File";
        String decryptedFile = "Decrypted File";
        encryptFile(inputFileName, encryptedFile);
        FileDecryption.decryptFile(encryptedFile, decryptedFile);
    }
    public static void encryptFile(String inputFileName,
        String encryptedFile)
    throws IOException, FileNotFoundException {
        File file1 = new File(inputFileName);

        FileInputStream fis = new FileInputStream(file1);
        FileOutputStream fos = new FileOutputStream(encryptedFile);
        int[] encrypt = {
            100
        };

        DataOutputStream outputFile =
            new DataOutputStream(new FileOutputStream("Encrypt.dat"));

        for (int i = 0; i < encrypt.length; i++)
            fos.write(encrypt[i] + 100);

        System.out.println("Encryption done.");

        outputFile.close();
    }
}

class FileDecryption {
    public static void decryptFile(String inputFileName,
        String encryptedFile)
    throws IOException, FileNotFoundException {
        File file1 = new File(inputFileName);

        FileInputStream fis = new FileInputStream(file1);
        FileOutputStream fos = new FileOutputStream(encryptedFile);
        int[] decrypt = {
            0
        };

        DataInputStream inputFile =
            new DataInputStream(new FileInputStream("Encrypt.dat"));

        for (int i = 0; i < decrypt.length; i--)
            fos.write(decrypt[i] - 100);

        System.out.println("Decryption done.");

        inputFile.close();


 }
}

我需要做什么才能让“演示文件”存在？什么是好的、简单的测试代码？我应该把评论放在哪里？我不想要一大堆不必要的评论，尽管我不知道哪些评论是必要的

Answer 1

要创建演示文件，只需使用文本编辑器，将要加密的文本放入其中：我放入演示文件。将txt文件放入名为的子文件夹中/数据/

/数据/演示文件。txt

abc 

然后输入路径/文件名。代码中的ext：

    String inputFileName = "./data/DemoFile.txt";

此外，下面使用while循环来处理FileInputStream对象，并逐个字符地读取文件来进行加密和解密，我认为这正是您的意图

        public static void main ( String[] args ) throws IOException {
            String inputFileName = "./data/DemoFile.txt";
            String encryptedFile = "./data/Encrypted.txt";
            String decryptedFile = "./data/Decrypted.txt";
            encryptFile                 ( inputFileName, encryptedFile );
            FileDecryption.decryptFile  ( encryptedFile, decryptedFile );
        }

        public static void encryptFile ( String inputFileName, String encryptedFile )
            throws IOException,
            FileNotFoundException {
            File file1 = new File ( inputFileName );

            FileInputStream     fis = new FileInputStream   ( file1 );
            FileOutputStream    fos = new FileOutputStream  ( encryptedFile );
            int[] encrypt = { 100 };

            DataOutputStream outputFile = new DataOutputStream ( new FileOutputStream ( encryptedFile ) );

            //for ( int i = 0; i < encrypt.length; i++ ) { 
            int r;
            while ((r = fis.read()) != -1) {
                char ch = (char) r;
                System.out.println ( "Reading   ["+ ch + "]" );
                fos.write ( ch+encrypt[0] );
                System.out.println ( "Encrypted ["+ ch+encrypt[0] + "]" );
            }

            System.out.println("Encryption done.");

            outputFile.close();
        }
    }

    class FileDecryption {
        public static void decryptFile ( String inputFileName, String encryptedFile )
            throws IOException,
            FileNotFoundException {
            File file1 = new File(inputFileName);

            FileInputStream fis = new FileInputStream(file1);
            FileOutputStream fos = new FileOutputStream(encryptedFile);
            int[] decrypt = { 100 };

            DataInputStream inputFile = new DataInputStream(new FileInputStream(encryptedFile));

            //for ( int i = 0; i < decrypt.length; i  )
            //    fos.write(decrypt[i] - 100);

            int r;
            while ((r = fis.read()) != -1) {
                char ch = (char) (r-decrypt[0]);
                System.out.println ( "Reading   ["+ ch + "]" );
                fos.write ( ch );
                System.out.println ( "Decrypted ["+ (ch) + "]" );
            }

            System.out.println("Decryption done.");
            inputFile.close();

        }
    }

我希望这能回答你的问题。代码应该能帮助你实现目标。。。阿德姆