用Java语言设计并实现DES加密解密程序，利用实现的DES加密解密程序分别对字符串、文本、图像等数据进行加密和解密。

以下是Java语言实现DES加密解密程序的示例代码：

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

public class DesUtil {
    private static final String ALGORITHM = "DES";

    public static SecretKey generateKey() throws NoSuchAlgorithmException {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM);
        return keyGenerator.generateKey();
    }

    public static byte[] encrypt(byte[] data, SecretKey secretKey) throws Exception {
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return cipher.doFinal(data);
    }

    public static byte[] decrypt(byte[] data, SecretKey secretKey) throws Exception {
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        return cipher.doFinal(data);
    }

    public static void encryptFile(String inputFile, String outputFile, SecretKey secretKey) throws Exception {
        byte[] data = Files.readAllBytes(Paths.get(inputFile));
        byte[] encryptedData = encrypt(data, secretKey);
        FileOutputStream outputStream = new FileOutputStream(outputFile);
        outputStream.write(encryptedData);
        outputStream.close();
    }

    public static void decryptFile(String inputFile, String outputFile, SecretKey secretKey) throws Exception {
        byte[] data = Files.readAllBytes(Paths.get(inputFile));
        byte[] decryptedData = decrypt(data, secretKey);
        FileOutputStream outputStream = new FileOutputStream(outputFile);
        outputStream.write(decryptedData);
        outputStream.close();
    }

    public static void main(String[] args) throws Exception {
        String data = "Hello, world!";
        SecretKey secretKey = generateKey();
        byte[] encryptedData = encrypt(data.getBytes(), secretKey);
        byte[] decryptedData = decrypt(encryptedData, secretKey);
        System.out.println("Original data: " + data);
        System.out.println("Encrypted data: " + Base64.getEncoder().encodeToString(encryptedData));
        System.out.println("Decrypted data: " + new String(decryptedData));

        String inputFile = "test.txt";
        String encryptedFile = "test_encrypted.txt";
        String decryptedFile = "test_decrypted.txt";
        Files.write(Paths.get(inputFile), data.getBytes());
        encryptFile(inputFile, encryptedFile, secretKey);
        decryptFile(encryptedFile, decryptedFile, secretKey);
        String decryptedFileContent = new String(Files.readAllBytes(Paths.get(decryptedFile)));
        System.out.println("Original file content: " + data);
        System.out.println("Decrypted file content: " + decryptedFileContent);
    }
}

使用示例：

String data = "Hello, world!";
SecretKey secretKey = DesUtil.generateKey();
byte[] encryptedData = DesUtil.encrypt(data.getBytes(), secretKey);
byte[] decryptedData = DesUtil.decrypt(encryptedData, secretKey);
System.out.println("Original data: " + data);
System.out.println("Encrypted data: " + Base64.getEncoder().encodeToString(encryptedData));
System.out.println("Decrypted data: " + new String(decryptedData));

String inputFile = "test.txt";
String encryptedFile = "test_encrypted.txt";
String decryptedFile = "test_decrypted.txt";
Files.write(Paths.get(inputFile), data.getBytes());
DesUtil.encryptFile(inputFile, encryptedFile, secretKey);
DesUtil.decryptFile(encryptedFile, decryptedFile, secretKey);
String decryptedFileContent = new String(Files.readAllBytes(Paths.get(decryptedFile)));
System.out.println("Original file content: " + data);
System.out.println("Decrypted file content: " + decryptedFileContent);

以上代码中，`generateKey()` 方法用于生成一个随机的DES密钥；`encrypt()` 方法用于加密数据；`decrypt()` 方法用于解密数据；`encryptFile()` 和 `decryptFile()` 方法分别用于加密和解密文件。该程序支持对字符串、文本文件和图像文件进行加密和解密。