java中加密解密工具类

在工作中经常遇到需要加密、解密的场景。例如用户的手机号等信息，在保存到数据库的过程中，需要对数据进行加密。取出时进行解密。

 

public class DEStool {

    private String sKey;

    public DEStool() {
        //默认构造函数提供默认密钥
        sKey = "des@#$12";
    }

    public DEStool(String securityKey) {
        if (securityKey.length() < 8) {
            throw new IllegalArgumentException("密钥长度至少8位");
        }
        this.sKey = securityKey;
    }

    private Cipher makeCipher() throws Exception{
        return Cipher.getInstance("DES");
    }

    private SecretKey makeKeyFactory() throws Exception{
        SecretKeyFactory des = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = des.generateSecret(new DESKeySpec(sKey.getBytes()));
        return secretKey;
    }

    public String encrypt(String text) throws Exception{
        Cipher cipher = makeCipher();
        SecretKey secretKey = makeKeyFactory();
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return new String(Base64.encodeBase64(cipher.doFinal(text.getBytes())));
    }

    public String decrypt(String text) throws Exception{
        Cipher cipher = makeCipher();
        SecretKey secretKey = makeKeyFactory();
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        return new String(cipher.doFinal(Base64.decodeBase64(text.getBytes())));
    }

    public static void main(String[] args) {
        DEStool tool = new DEStool("nice1234");
        String content = "中国";
        System.out.println("原文内容："+content);
        String encrpt = null;
        try {
            encrpt = tool.encrypt(content);
        } catch (Exception e) {
            e.printStackTrace();
        }

        System.out.println("加密后："+encrpt + ", 长度=" + encrpt.length());

        String descript =null;

        try {
            descript = tool.decrypt(encrpt);
        } catch (Exception e) {
            e.printStackTrace();
        }

        System.out.println("解密后：" + descript);
    }
}