content: package site.alanliang.geekblog.utils;
  
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  
  /**
   * Created by limi on 2017/10/15.
   */
  public class MD5Util {
  
      /**
       * MD5加密类
       *
       * @param str 要加密的字符串
       * @return 加密后的字符串
       */
      public static String code(String str) {
          try {
              MessageDigest md = MessageDigest.getInstance("MD5");
              md.update(str.getBytes());
              byte[] byteDigest = md.digest();
              int i;
              StringBuffer buf = new StringBuffer("");
              for (int offset = 0; offset < byteDigest.length; offset++) {
                  i = byteDigest[offset];
                  if (i < 0)
                      i += 256;
                  if (i < 16)
                      buf.append("0");
                  buf.append(Integer.toHexString(i));
              }
              //32位加密
              return buf.toString();
              // 16位的加密
              //return buf.toString().substring(8, 24);
          } catch (NoSuchAlgorithmException e) {
              e.printStackTrace();
              return null;
          }
  
      }
  }
  