md5算法

package common; /** * MD5加密 * @author ellison */ import java.math.*; import java.security.*; import java.security.spec.*; public class MD5 { char hexChars[] ={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'}; public String convert32(String str){ try { byte[] bytes = str.getBytes(); //实例化一个messageDigest类的对象，如果采用SHA加密，可以将MD5转换成SHA MessageDigest md = MessageDigest.getInstance("MD5"); md.update(bytes); //获取加密后的摘要digest bytes = md.digest(); int j = bytes.length; char[] chars = new char[j * 2]; int k = 0; for (int i = 0; i < bytes.length; i++) { byte b = bytes[i]; chars[k++] = hexChars[b>>>4&0xf]; chars[k++] = hexChars[b&0xf]; } return new String(chars); } catch (Exception e) { return null; } } //获取16位的MD5加密数据 public String convert16(String s){ String ns = convert32(s).substring(8,24); return ns; } }