Java实现文件加解密,并使用AES算法
时间: 2024-04-09 09:31:35 浏览: 21
当然!以下是使用AES算法实现文件加密和解密的Java代码示例:
```java
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class FileEncryptionDecryption {
private static final String ALGORITHM = "AES";
public static void encryptFile(String inputFile, String outputFile, String key) throws IOException {
try {
SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM);
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
FileInputStream inputStream = new FileInputStream(inputFile);
FileOutputStream outputStream = new FileOutputStream(outputFile);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
byte[] output = cipher.update(buffer, 0, bytesRead);
if (output != null) {
outputStream.write(output);
}
}
byte[] output = cipher.doFinal();
if (output != null) {
outputStream.write(output);
}
inputStream.close();
outputStream.flush();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void decryptFile(String inputFile, String outputFile, String key) throws IOException {
try {
SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM);
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, secretKey);
FileInputStream inputStream = new FileInputStream(inputFile);
FileOutputStream outputStream = new FileOutputStream(outputFile);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
byte[] output = cipher.update(buffer, 0, bytesRead);
if (output != null) {
outputStream.write(output);
}
}
byte[] output = cipher.doFinal();
if (output != null) {
outputStream.write(output);
}
inputStream.close();
outputStream.flush();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
String inputFile = "plaintext.txt";
String encryptedFile = "encrypted.txt";
String decryptedFile = "decrypted.txt";
String key = "mySecretKey";
try {
encryptFile(inputFile, encryptedFile, key);
System.out.println("File encrypted successfully.");
decryptFile(encryptedFile, decryptedFile, key);
System.out.println("File decrypted successfully.");
} catch (IOException e) {
e.printStackTrace();
}
}
}
```
在这个示例中,我们添加了一个`decryptFile`方法来实现文件解密。它与`encryptFile`方法类似,只是在`Cipher`对象的初始化中使用了`Cipher.DECRYPT_MODE`模式。
请注意,为了简化示例,我们使用相同的密钥来进行加密和解密。在实际应用中,你可能需要更安全的密钥管理和分发机制。另外,为了使代码更健壮,你可能还需要处理异常、使用合适的缓冲区大小等。