poi/poi/src/main/java/org/apache/poi/util/RandomSingleton.java

/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You 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 org.apache.poi.util;

import java.security.SecureRandom;

/*
If it is important that the generated Random numbers not be guessable,
you MUST NOT create a new Random for each random number; the values are too easily guessable.

You should strongly consider using a java.security.SecureRandom instead
(and avoid allocating a new SecureRandom for each random number needed).
*/

public class RandomSingleton {
    private static final SecureRandom INSTANCE = new SecureRandom();

    public static SecureRandom getInstance() {
        return INSTANCE;
    }
}