Message Digest Algorithm MD5 (Chinese name is Message Digest Algorithm Fifth Edition) is a hash function widely used in the field of computer security and is a relatively commonly used hash algorithm.
There are two methods to achieve this in Java. Let’s talk about the more troublesome one first, the code:
Copy the code code as follows:
public class md5_test {
//MD5 string constant
private final static String[] hexDigits = { "0", "1", "2", "3", "4",
"5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
MessageDigest messageDigest= MessageDigest.getInstance("MD5");
System.out.println(byteArrayToHexString(messageDigest.digest("baidu.com".getBytes())));
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private 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();
}
/** Convert a byte into a string in hexadecimal form*/
private static String byteToHexString(byte b) {
int n = b;
if (n < 0)
n = 256 + n;
int d1 = n / 16;
int d2 = n % 16;
return hexDigits[d1] + hexDigits[d2];
}
}
The following is simple, but you need to import a jar package: commons-codec,
For example, I use this commons-codec-1.4.jar code:
Copy the code code as follows:
import org.apache.commons.codec.digest.DigestUtils;
public class ToMain {
public static void main(String[] args) {
System.out.println(DigestUtils.md5Hex("baidu.com"));
}
}