MD5 加密 参数加密解密

import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Calendar;

public class Md5Utils {

public static void main(String[] args) {
// 请求参数加密
String verifyCode = "transType=C000&custId=custId";
String queryString = "transType=C000&custId=custId" + "&verifyCode="
+ getVerifyCode(MD5_SEED, verifyCode);
System.out.println(queryString);

// 返回参数加解密
String enc = encode(verifyCode);
String dec = decode(enc);
System.out.println(enc);
System.out.println(dec);

}

private static final String key0 = "aaaaaaa";
private static final Charset charset = Charset.forName("UTF-8");
private static byte[] keyBytes = key0.getBytes(charset);

// 加密
public static String encode(String enc) {
byte[] b = enc.getBytes(charset);
for (int i = 0, size = b.length; i < size; i++) {
for (byte keyBytes0 : keyBytes) {
b[i] = (byte) (b[i] ^ keyBytes0);
}
}
return new String(b);
}

// 解密
public static String decode(String dec) {
byte[] e = dec.getBytes(charset);
byte[] dee = e;
for (int i = 0, size = e.length; i < size; i++) {
for (byte keyBytes0 : keyBytes) {
e[i] = (byte) (dee[i] ^ keyBytes0);
}
}
return new String(e);
}

/***********************************************************************/
/**
* 文忠接口需要的秘钥
*/
private static final String MD5_SEED = "bbbbbbbbkeykey";

private static String getVerifyCode(String md5, String verifyCode) {
return getMD5Value(md5 + getCurrentDate() + verifyCode);
}

private static String getCurrentDate() {
StringBuffer buffer = new StringBuffer();
Calendar now = Calendar.getInstance();
String monthValue = null;
String dayValue = null;

int year = now.get(Calendar.YEAR);
int month = now.get(Calendar.MONTH) + 1;
int DAY_OF_MONTH = now.get(Calendar.DAY_OF_MONTH);
if (month < 10) {
monthValue = "0" + String.valueOf(month);
} else {
monthValue = String.valueOf(month);
}
if (DAY_OF_MONTH < 10) {
dayValue = "0" + String.valueOf(DAY_OF_MONTH);
} else {
dayValue = String.valueOf(DAY_OF_MONTH);
}
return buffer.append(year).append(monthValue).append(dayValue)
.toString();
}

private static String getMD5Value(String preValue) {
String resultString = null;
if (preValue != null && preValue.length() != 0) {
try {
MessageDigest md = MessageDigest.getInstance("MD5");
resultString = byteToString(md.digest(preValue.getBytes()));

} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
}
return resultString;
}

// 转换字节数组为16进制字串
private static String byteToString(byte[] bByte) {
StringBuffer sBuffer = new StringBuffer();
for (int i = 0; i < bByte.length; i++) {
sBuffer.append(byteToArrayString(bByte[i]));
}
return sBuffer.toString();
}

// 返回形式为数字跟字符串
private static String byteToArrayString(byte bByte) {
int iRet = bByte;
if (iRet < 0) {
iRet += 256;
}
int iD1 = iRet / 16;
int iD2 = iRet % 16;
return strDigits[iD1] + strDigits[iD2];
}

// 全局数组
private final static String[] strDigits = { "0", "1", "2", "3", "4", "5",
"6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };

}