如何制作基于IO流技术的简易文件加密小程序？

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效果展示：该程序实现了对文件内容的加密和解密功能。

代码展示：javapackage com.xy;

import java.io.*;import java.util.Objects;import java.util.Scanner;

/** * @author 谢阳 * @version 1.8.0_131 * @date 2023/1/15 23:07 * @description 文件加密应用 */public class FileEncryptionApp { private static final String ALGORITHM=AES; private static final String ENCRYPTION_KEY=your_encryption_key;

public static void main(String[] args) { Scanner scanner=new Scanner(System.in); System.out.println(请选择操作：1. 加密文件 2. 解密文件); int choice=scanner.nextInt(); scanner.nextLine(); // 消耗换行符

if (choice==1) { System.out.println(请输入文件路径：); String filePath=scanner.nextLine(); encryptFile(filePath); } else if (choice==2) { System.out.println(请输入文件路径：); String filePath=scanner.nextLine(); decryptFile(filePath); } else { System.out.println(无效的操作选择！); } }

private static void encryptFile(String filePath) { try { File file=new File(filePath); if (!file.exists()) { System.out.println(文件不存在！); return; }

FileInputStream fis=new FileInputStream(file); ObjectInputStream ois=new ObjectInputStream(new GZIPOutputStream(fis)); String originalContent=(String) ois.readObject(); ois.close();

String encryptedContent=encryptContent(originalContent); saveEncryptedContent(encryptedContent, filePath);

System.out.println(文件加密成功！); } catch (Exception e) { e.printStackTrace(); } }

private static void decryptFile(String filePath) { try { File file=new File(filePath); if (!file.exists()) { System.out.println(文件不存在！); return; }

FileInputStream fis=new FileInputStream(file); ObjectInputStream ois=new ObjectInputStream(new GZIPInputStream(fis)); String encryptedContent=(String) ois.readObject(); ois.close();

String decryptedContent=decryptContent(encryptedContent); saveDecryptedContent(decryptedContent, filePath);

System.out.println(文件解密成功！); } catch (Exception e) { e.printStackTrace(); } }

private static String encryptContent(String content) throws Exception { Cipher cipher=Cipher.getInstance(ALGORITHM); SecretKeySpec keySpec=new SecretKeySpec(ENCRYPTION_KEY.getBytes(), ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE, keySpec); return Base64.getEncoder().encodeToString(cipher.doFinal(content.getBytes())); }

private static String decryptContent(String encryptedContent) throws Exception { Cipher cipher=Cipher.getInstance(ALGORITHM); SecretKeySpec keySpec=new SecretKeySpec(ENCRYPTION_KEY.getBytes(), ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, keySpec); return new String(cipher.doFinal(Base64.getDecoder().decode(encryptedContent))); }

private static void saveEncryptedContent(String content, String filePath) throws IOException { File file=new File(filePath + .enc); try (BufferedWriter writer=new BufferedWriter(new FileWriter(file))) { writer.write(content); } }

private static void saveDecryptedContent(String content, String filePath) throws IOException { File file=new File(filePath + .dec); try (BufferedWriter writer=new BufferedWriter(new FileWriter(file))) { writer.write(content); } }}

效果展示

代码展示

package com.xy; import java.io.*; import java.util.Objects; import java.util.Scanner; /** * @author 谢阳 * @version 1.8.0_131 * @date 2023/1/15 23:07 * @description */ public class FileEncryptionApp { private static final byte[] IS_CODED = new byte[4]; // 默认解密校验码 private static Integer mode; // 模式选择 1 加密 2解密 private static Scanner scanner = new Scanner(System.in); private static String destName; static { IS_CODED[0] = 2; IS_CODED[1] = 0; IS_CODED[2] = 2; IS_CODED[3] = 3; } public static void main(String[] args) throws IOException { showMenu(); } /** * 菜单展示 * * @throws IOException */ private static void showMenu() throws IOException { boolean loop = true; while (loop) { System.out.println("----------------文件加密、解密小程序---------------"); System.out.println("\t\t\t\t\t1 文件加密"); System.out.println("\t\t\t\t\t2 文件解密"); System.out.println("\t\t\t\t\t3 退出"); System.out.println("-----------------------------------------------"); System.out.print("请输入您的选择:"); char key = scanner.next().charAt(0); switch (key) { case '1': System.out.print("请输入需加密文件路径:"); String enCodePath = scanner.next(); System.out.print("请输入文件的加密密码:"); String enCodePassword = scanner.next(); System.out.println(enCode(enCodePath, enCodePassword) ? "加密成功,文件路径为:" + destName : "加密失败"); break; case '2': System.out.print("请输入需解密文件路径:"); String unCodePath = scanner.next(); System.out.print("请输入文件的解密密码:"); String unCodePassword = scanner.next(); System.out.println(unCode(unCodePath, unCodePassword) ? "解密成功,文件路径为:" + destName : "解密失败"); break; case '3': System.out.println("退出程序成功,欢迎您的再次使用~"); loop = false; break; default: System.out.println("您的输入有误,请重新输入:)"); } } } /** * 文件加密 * * @param path 文件路径 * @param password 加密文件密钥 * @return 是否加密成功 （true/false） */ private static boolean enCode(String path, String password) throws IOException { if (!checkPathAndPassword(path, password)) { return false; } // 加密后的文件名 destName = path.substring(0, path.lastIndexOf(".")) + "-coded" + path.substring(path.lastIndexOf(".")); try ( BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path)); BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destName)) ) { bos.write(IS_CODED);// 写入默认加密密钥 byte[] passwordBytes = password.getBytes(); for (int i = 0; i < passwordBytes.length; i++) { passwordBytes[i] ^= password.hashCode(); } bos.write(passwordBytes); // 写入用户加密密钥 byte[] buf = new byte[1024]; int len; int keyHash = password.hashCode(); // 加密hash值 long length = new File(path).length() % 10; // 文件长度 while ((len = bis.read(buf)) != -1) { // 加密 for (int i = 0; i < len; i++) { //buf[i] ^= keyHash; buf[i] = (byte) ((buf[i] ^ keyHash) + length); } bos.write(buf, 0, len); } } return true; } /** * 文件解密 * * @param path 文件路径 * @param password 解密文件密钥 * @return 是否解密成功 （true/false) */ private static boolean unCode(String path, String password) throws IOException { if (!checkPathAndPassword(path, password)) { return false; } if (new File(path).length() < IS_CODED.length + password.getBytes().length) { System.out.println("该文件不属于加密文件"); return false; } // 解密后的文件名 destName = path.substring(0, path.lastIndexOf(".")) + "-unCode" + path.substring(path.lastIndexOf(".")); try ( BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path)); ) { // 验证默认密钥和用户密钥是否正确 if (!checkCodeAndPassword(bis, password)) { return false; } byte[] buf = new byte[1024]; int len; int keyHash = password.hashCode(); // 解密hash值 // 长度为上一次文件长度 long length = (new File(path).length() - password.getBytes().length - IS_CODED.length) % 10; try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destName))) { while ((len = bis.read(buf)) != -1) { // 解密 for (int i = 0; i < len; i++) { //buf[i] ^= keyHash; buf[i] = (byte) ((buf[i] - length) ^ keyHash); } bos.write(buf, 0, len); } } } return true; } /** * 验证默认密钥和用户密钥是否正确 * * @param bis * @param password 用户密码 * @return ture/false */ private static boolean checkCodeAndPassword(BufferedInputStream bis, String password) throws IOException { byte[] codedKey = new byte[IS_CODED.length]; // 默认加密密钥 bis.read(codedKey); // 验证默认密钥 for (int i = 0; i < IS_CODED.length; i++) { if (codedKey[i] != IS_CODED[i]) { System.out.println("该文件不属于加密文件"); return false; } } // 验证用户密钥 byte[] passwordBytes = password.getBytes(); byte[] pas = new byte[passwordBytes.length]; bis.read(pas); for (int i = 0; i < passwordBytes.length; i++) { if (pas[i] != (byte) (passwordBytes[i] ^ password.hashCode())) { System.out.println("文件解密密码错误"); return false; } } return true; } /** * 文件、文件路径、密钥检测 * * @param path 文件路径 * @param password 密钥 * @return 文件是否存在（true/false） */ private static boolean checkPathAndPassword(String path, String password) { if (Objects.isNull(path)) { System.out.println("文件路径不能为空"); return false; } if (Objects.isNull(password)) { System.out.println("用户密钥不能为空"); return false; } File file = new File(path); if (!file.exists()) { System.out.println("该路径不在在,请检查文件路径是否存在"); return false; } if (!file.isFile()) { System.out.println("该路径不是文件,请输入文件名"); return false; } if (!file.getName().contains(".")) { System.out.println("不知此该文件格式"); return false; } return true; } }