Java MD5加密算法工具类

package util;import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;public class MD5 {
public static String encrypt(String s) {
StringBuffer buf = new StringBuffer();
try {
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(s.getBytes());
byte[] bytes = md5.digest(); for (int i = 0; i < bytes.length; i++) {
int num = bytes[i];
if (num < 0) {
num += 256;
}

// 如果小于16，则加0补齐16进制两位数
if (num < 16) {
buf.append(0);
}
buf.append(Integer.toHexString(num));
}
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return buf.toString();
} public static void main(String[] args) {
String password = "HELLOhi";
System.out.println(encrypt(password));
}}