简单易懂的Java MD5加密教程

package com.troy.jpa.util; import java.security.MessageDigest; publicclass MD5Util { privatestaticfinalchar[] DIGITS_LOWER = newchar[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}; //通过MD5进行加密publicstatic String encrpytionByMd5(String data) throws Exception { //获取MD5的摘要 MessageDigest messageDigest = MessageDigest.getInstance("MD5"); //使用指定的直接更新摘要 messageDigest.update(data.getBytes()); //获取计算过后的数据byte[] digest = messageDigest.digest(); //将密文转成32为，输出成字符串returnnew String(encodeHex(digest)); } //字节数据装换privatestaticchar[] encodeHex(byte[] data) { //获取数据字节长度int n = data.length; //a << b 的意思就是a*2的b次方，>>就是除以char[] out = newchar[n << 1]; int i = 0; for(int v = 0; i < n; ++i) { out[v++] = DIGITS_LOWER[(240 & data[i]) >>> 4]; out[v++] = DIGITS_LOWER[15 & data[i]]; } return out; } publicstaticvoid main(String[] args) { try { String data = "123456"; String md5 = encrpytionByMd5(data); System.out.println(md5); } catch (Exception e) { e.printStackTrace(); } } }