轉載自：http://blog.sina.com.cn/s/blog_667ac0360102ed0w.html

  APP端開發為了省空間，不打算匯入apache-commons的jar包，可以使用JDK自帶的加密演算法； package com.common.util; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; //import org.apache.commons.codec.digest.DigestUtils; ///  // JDK自帶加密演算法  //   // @author iPan  // @version 2014-4-25  // public class MessageDigestUtils { public static String sha1(String text) { MessageDigest md = null; String outStr = null; try { md = MessageDigest.getInstance("SHA-1"); byte[] digest = md.digest(text.getBytes()); outStr = byteToString(digest); } catch (NoSuchAlgorithmException e) { throw new RuntimeException(e); } return outStr; } private static String byteToString(byte[] digest) { StringBuilder buf = new StringBuilder(); for (int i = 0; i < digest.length; i++) { String tempStr = Integer.toHexString(digest[i] & 0xff); if (tempStr.length() == 1) { buf.append("0").append(tempStr); } else { buf.append(tempStr); } } return buf.toString().toLowerCase(); } public static void main(String[] args) { // System.out.println(DigestUtils.sha1Hex("123456")); System.out.println(MessageDigestUtils.sha1("123456")); } }