如何在Java中处理Zip文件的加密解密

在Java中处理ZIP文件的加密和解密，可以使用java.util.zip包中的类和方法

1. 导入所需的库：

import java.io.*;
import java.util.zip.*;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

2. 创建一个方法来生成加密密钥：

public static SecretKeySpec generateEncryptionKey(String key) {
    try {
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        byte[] hash = md.digest(key.getBytes());
        return new SecretKeySpec(hash, "AES");
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

3. 创建一个方法来加密ZIP文件：

public static void encryptZipFile(String zipFilePath, String outputZipFile, SecretKeySpec key) {
    try {
        FileInputStream fis = new FileInputStream(zipFilePath);
        ZipInputStream zis = new ZipInputStream(fis);
        ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(outputZipFile));

        ZipEntry ze;
        while ((ze = zis.getNextEntry()) != null) {
            zos.putNextEntry();

            byte[] buffer = new byte[1024];
            int len;
            while ((len = zis.read(buffer)) > 0) {
                Cipher cipher = Cipher.getInstance("AES");
                cipher.init(Cipher.ENCRYPT_MODE, key);
                byte[] encryptedBytes = cipher.doFinal(buffer, 0, len);
                zos.write(encryptedBytes);
            }

            zos.closeEntry();
            zis.closeEntry();
        }

        zis.close();
        zos.close();
        fis.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

4. 创建一个方法来解密ZIP文件：

public static void decryptZipFile(String zipFilePath, String outputZipFile, SecretKeySpec key) {
    try {
        FileInputStream fis = new FileInputStream(zipFilePath);
        ZipInputStream zis = new ZipInputStream(fis);
        ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(outputZipFile));

        ZipEntry ze;
        while ((ze = zis.getNextEntry()) != null) {
            zos.putNextEntry();

            byte[] buffer = new byte[1024];
            int len;
            while ((len = zis.read(buffer)) > 0) {
                Cipher cipher = Cipher.getInstance("AES");
                cipher.init(Cipher.DECRYPT_MODE, key);
                byte[] decryptedBytes = cipher.doFinal(buffer, 0, len);
                zos.write(decryptedBytes);
            }

            zos.closeEntry();
            zis.closeEntry();
        }

        zis.close();
        zos.close();
        fis.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

5. 使用这些方法加密和解密ZIP文件：

public static void main(String[] args) {
    String zipFilePath = "path/to/your/input.zip";
    String encryptedZipFile = "path/to/your/encrypted.zip";
    String decryptedZipFile = "path/to/your/decrypted.zip";
    String key = "yourEncryptionKey16bytes"; // 16 bytes for AES-128, 24 bytes for AES-192, 32 bytes for AES-256

    SecretKeySpec keySpec = generateEncryptionKey(key);

    // Encrypt the ZIP file
    encryptZipFile(zipFilePath, encryptedZipFile, keySpec);

    // Decrypt the ZIP file
    decryptZipFile(encryptedZipFile, decryptedZipFile, keySpec);
}

请注意，这个示例使用了AES加密算法。你可以根据需要选择其他加密算法。同时，确保密钥长度与所选加密算法相匹配。例如，对于AES-128，密钥长度应为16字节，对于AES-192，密钥长度应为24字节，对于AES-256，密钥长度应为32字节。