/**
* Copyright (c) 2011-2012, James Zhan 詹波 (jfinal@126.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.jfinal.plugin.auth;
import java.security.SecureRandom;
import java.util.Random;
import javax.servlet.http.HttpServletRequest;
/**
* TODO 考虑改名为 SessionIdBuilder
*/
public class AccessTokenBuilder {
private static Random random;
private static boolean weakRandom;
private static int hashCode = new AccessTokenBuilder().hashCode();
private AccessTokenBuilder() {
try {
// This operation may block on some systems with low entropy. See
// this page for workaround suggestions:
// http://docs.codehaus.org/display/JETTY/Connectors+slow+to+startup
// System.out.println("Init SecureRandom.");
random = new SecureRandom();
weakRandom = false;
} catch (Exception e) {
random = new Random();
weakRandom = true;
System.err.println("Could not generate SecureRandom for accessToken randomness");
}
}
public static String getAccessToken(HttpServletRequest request) {
String accessToken = null;
while (accessToken == null || accessToken.length() == 0) {
long r0 = weakRandom ? (hashCode ^ Runtime.getRuntime().freeMemory() ^ random.nextInt() ^ (((long)request.hashCode()) << 32)) : random.nextLong();
long r1 = random.nextLong();
if (r0 < 0) r0 = -r0;
if (r1 < 0) r1 = -r1;
accessToken = Long.toString(r0, 36) + Long.toString(r1, 36);
}
return accessToken;
}
}