md5 加密 demo

import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class MD5Example { public static void main(String[] args) { String input = "Hello World"; String md5Hash = getMD5(input); System.out.println("原文：" + input); System.out.println("MD5：" + md5Hash); } public static String getMD5(String input) { try { // 1. 获取 MD5 算法实例 MessageDigest md = MessageDigest.getInstance("MD5"); // 2. 计算哈希值（字节数组） byte[] hashBytes = md.digest(input.getBytes()); // 3. 将字节数组转换为十六进制字符串 StringBuilder sb = new StringBuilder(); for (byte b : hashBytes) { sb.append(String.format("%02x", b)); } return sb.toString(); } catch (NoSuchAlgorithmException e) { throw new RuntimeException("MD5算法不存在", e); } } }