MD5加密工具类

//MD5加密操作是最典型、最常用的技术之一，在很多网络数据传输、参数传递开发当中均会有所涉及，故工具之。

import java.security.MessageDigest;

public class MD5 {
    private MessageDigest md5 = null;

    public MD5() {
        try {
            md5 = MessageDigest.getInstance("MD5");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // MD5加码。32位
    public String MD5(String inStr) {
        char[] charArray = inStr.toCharArray();
        byte[] byteArray = new byte[charArray.length];

        for (int i = 0; i < charArray.length; i++)
            byteArray[i] = (byte) charArray[i];

        byte[] md5Bytes = md5.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();

        for (int i = 0; i < md5Bytes.length; i++) {
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16)
                hexValue.append("0");
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString().toUpperCase();
    }

    // MD5加码。32位
    public String MD5_Normal(String inStr) {
        char[] charArray = inStr.toCharArray();
        byte[] byteArray = new byte[charArray.length];

        for (int i = 0; i < charArray.length; i++)
            byteArray[i] = (byte) charArray[i];

        byte[] md5Bytes = md5.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();

        for (int i = 0; i < md5Bytes.length; i++) {
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16)
                hexValue.append("0");
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString();
    }

    // 可逆的加密算法
    public static String KL(String inStr) {
        // String s = new String(inStr);
        char[] a = inStr.toCharArray();
        for (int i = 0; i < a.length; i++) {
            a[i] = (char) (a[i] ^ ‘t‘);
        }
        String s = new String(a);
        return s;
    }

    // 加密后解密
    public static String JM(String inStr) {
        char[] a = inStr.toCharArray();
        for (int i = 0; i < a.length; i++) {
            a[i] = (char) (a[i] ^ ‘t‘);
        }
        String k = new String(a);
        return k;
    }

    // 测试主函数
    public static void main(String args[]) throws Exception {
        MD5 md5 = new MD5();
        // conac编办H3mnoa83Eb3T
        System.out.println(md5.MD5(new String("this is a string"
                .getBytes("utf-8"), "iso8859-1")));
    }
}