ApiUtils.java

/*
 * Copyright (C) 2013 Simon Vig Therkildsen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.simonvt.cathode.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public final class ApiUtils {

  private static final char[] DIGITS = {
      '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f',
  };

  private ApiUtils() {
  }

  public static String getSha(String string) {
    return getSha(string, "UTF-8");
  }

  public static String getSha(String string, String encoding) {
    try {
      byte[] sha = MessageDigest.getInstance("SHA").digest(string.getBytes(encoding));
      return new String(encodeHex(sha));
    } catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
    } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
    }

    return string;
  }

  private static char[] encodeHex(byte[] data) {
    int l = data.length;
    char[] out = new char[l << 1];

    for (int i = 0, j = 0; i < l; i++) {
      out[j++] = DIGITS[(0xF0 & data[i]) >>> 4];
      out[j++] = DIGITS[0x0F & data[i]];
    }
    return out;
  }
}