Java项目中字符串加密技术源码：

import java.security.MessageDigest;

public class MD5 {
private static final String[] hexDigits = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
"e", "f" };

public static String byteArrayToHexString(byte[] b) {
StringBuffer resultSb = new StringBuffer();
for (int i = 0; i < b.length; ++i)
resultSb.append(byteToHexString(b[i]));

return resultSb.toString();
}

private static String byteToHexString(byte b) {
int n = b;
if (n < 0)
n += 256;
int d1 = n / 16;
int d2 = n % 16;
return hexDigits[d1] + hexDigits[d2];
}

public static String MD5Encode(String origin) {

String resultString = null;
try {
resultString = new String(origin);
MessageDigest md = MessageDigest.getInstance("MD5");
resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
}
catch (java.lang.Exception md) {
}
return resultString + resultString.substring(0, 3).toLowerCase();
}

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.print(MD5Encode("1"));
}
}