com.generallycloud.baseio.common.MD5Token Maven / Gradle / Ivy
/*
* Copyright 2015-2017 GenerallyCloud.com
*
* 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 com.generallycloud.baseio.common;
import java.nio.charset.Charset;
import java.security.MessageDigest;
public class MD5Token {
private static char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
private static MD5Token instance = new MD5Token();
private MD5Token() {
}
public static MD5Token getInstance() {
return instance;
}
public String getShortToken(String value,Charset encoding) {
return encoder(value,encoding).substring(8, 24);
}
public String getLongToken(String value,Charset encoding) {
return encoder(value,encoding).toString();
}
private StringBuilder encoder(String value,Charset encoding) {
if (value == null) {
value = "";
}
MessageDigest md5 = null;
try {
md5 = MessageDigest.getInstance("MD5");
md5.update(value.getBytes(encoding));
} catch (Exception e) {
throw new RuntimeException(e.getMessage(),e);
}
return toHex(md5.digest());
}
private StringBuilder toHex(byte[] bytes) {
StringBuilder str = new StringBuilder(32);
int length = bytes.length;
for (int i = 0; i < length; i++) {
str.append(hexDigits[(bytes[i] & 0xf0) >> 4]);
str.append(hexDigits[bytes[i] & 0x0f]);
}
return str;
}
}