java8 des加密(效率高)

一般常用的是DES/CBC/PKCS5Padding

注意:我这里的des加密,最后都经过了base64编码, 是否需要看你的需求

import javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.Key;
import java.util.Base64;

public class DESUtil {

    /**
     * 偏移变量，固定占8位字节
     */
    //private final static String IV_PARAMETER = "12345678";

    private final static byte[] IV_DEFAULT = {1, 1, 1, 1, 1, 1, 1, 1};
    /**
     * 密钥算法
     */
    private static final String ALGORITHM = "DES";
    /**
     * 加密/解密算法-工作模式-填充模式
     */
    private static final String CIPHER_ALGORITHM = "DES/CBC/PKCS5Padding";
    /**
     * 默认编码
     */
    private static final String CHARSET = "utf-8";

    /**
     * 生成key
     *
     * @param password
     * @return
     * @throws Exception
     */
    private static Key generateKey(String password) throws Exception {
        DESKeySpec dks = new DESKeySpec(password.getBytes(CHARSET));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
        return keyFactory.generateSecret(dks);
    }

    /**
     * DES加密字符串
     *
     * @param password 加密密码，长度不能够小于8位
     * @param data     待加密字符串
     * @return 加密后内容
     */
    public static String encrypt(String password, String data) {
        if (password == null || password.length() < 8) {
            throw new RuntimeException("加密失败，key不能小于8位");
        }
        if (data == null)
            return null;
        try {
            Key secretKey = generateKey(password);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
            IvParameterSpec iv = new IvParameterSpec(IV_DEFAULT);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
            byte[] bytes = cipher.doFinal(data.getBytes(CHARSET));
            //JDK1.8及以上可直接使用Base64，JDK1.7及以下可以使用BASE64Encoder,或者使用Apache的common
            //Android平台可以使用android.util.Base64
            return new String(Base64.getEncoder().encode(bytes));
        } catch (Exception e) {
            e.printStackTrace();
            return data;
        }
    }

    /**
     * DES解密字符串
     * @param password 解密密码，长度不能够小于8位
     * @param data     待解密字符串
     * @return 解密后内容
     */
    public static String decrypt(String password, String data) {
        if (password == null || password.length() < 8) {
            throw new RuntimeException("加密失败，password不能小于8位");
        }
        if (data == null) {
            return "";
        }
        try {
            //先Base64解码
            byte[] text = Base64.getDecoder().decode(data.getBytes(CHARSET));
            Key secretKey = generateKey(password);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
            IvParameterSpec iv = new IvParameterSpec(IV_DEFAULT);
            cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
            byte[] original = cipher.doFinal(text);
            return new String(original,CHARSET);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }


    /**
     * DES加密文件
     *
     * @param srcFile  待加密的文件
     * @param destFile 加密后存放的文件路径
     * @return 加密后的文件路径
     */
    public static String encryptFile(String password, String srcFile, String destFile) {
        try {
            byte[] bytes = Files.readAllBytes(Paths.get(srcFile));
            Key secretKey = generateKey(password);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
            IvParameterSpec iv = new IvParameterSpec(IV_DEFAULT);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
            //byte[] cip = cipher.doFinal(bytes);
            //base64加密
            byte[] encodes = Base64.getEncoder().encode(cipher.doFinal(bytes));
            //写文件
            Files.write(Paths.get(destFile),encodes);
            System.out.println("文件加密完成.目标路径->"+destFile);
            return destFile;
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    /**
     * DES解密文件
     * @param srcFile  已加密的文件
     * @param destFile 解密后存放的文件路径
     * @return 解密后的文件路径
     */
    public static String decryptFile2(String password, String srcFile, String destFile) {
        if (password == null || password.length() < 8) {
            throw new RuntimeException("加密失败，password不能小于8位");
        }

        try {
            //先base64解密,这里的如果是27M文件,大概需要2分钟左右,很慢,不推荐使用这种方式
            InputStream inWrap = Base64.getDecoder().wrap(new FileInputStream(srcFile));
            File file = new File(destFile);
            if (!file.exists()) {
                file.getParentFile().mkdirs();
                file.createNewFile();
            }
            IvParameterSpec iv = new IvParameterSpec(IV_DEFAULT);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
            cipher.init(Cipher.DECRYPT_MODE, generateKey(password), iv);
            //InputStream is = new FileInputStream(srcFile);
            OutputStream out = new FileOutputStream(destFile);
            CipherOutputStream cos = new CipherOutputStream(out, cipher);
            byte[] buffer = new byte[1024 * 2];
            int r;
            while ((r = inWrap.read(buffer)) >= 0) {
                cos.write(buffer, 0, r);
            }
            cos.close();
            inWrap.close();
            out.close();
            System.out.println("解密完成,目标路径->"+destFile);
            return destFile;
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }


    /**
     * DES解密文件
     * 效率很高，27M文件1.149s，推荐
     * @param srcFile  已加密的文件
     * @param destFile 解密后存放的文件路径
     * @return 解密后的文件路径
     */
    public static String decryptFile(String password, String srcFile, String destFile) {
        if (password == null || password.length() < 8) {
            throw new RuntimeException("加密失败，password不能小于8位");
        }
        try {
         /*   File file = new File(destFile);
            if (!file.exists()) {
                file.getParentFile().mkdirs();
                file.createNewFile();
            }*/
            //先Base64解码
            byte[] src = Files.readAllBytes(Paths.get(srcFile));
            byte[] text = Base64.getDecoder().decode(src);
            Key secretKey = generateKey(password);
            Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
            IvParameterSpec iv = new IvParameterSpec(IV_DEFAULT);
            cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
            //byte[] original = cipher.doFinal(text);
            //写文件
            Files.write(Paths.get(destFile),cipher.doFinal(text));
            System.out.println("解密完成,目标路径->"+destFile);
            return destFile;
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }
    }