com.feilong.core.Alphabet.java Source code

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Here is the source code for com.feilong.core.Alphabet.java

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/*
 * Copyright (C) 2008 feilong
 *
 * 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.feilong.core;

/**
 * ?.
 *
 * @author <a href="http://feitianbenyue.iteye.com/">feilong</a>
 * @see <a href="http://algs4.cs.princeton.edu/50strings/Alphabet.java.html">Alphabet.java</a>
 * @since 1.5.3
 */
public final class Alphabet {

    /** The decimal alphabet { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }. */
    public static final String DECIMAL = "0123456789";

    /** ??The lowercase alphabet { a, b, c, ..., z }. */
    public static final String LOWERCASE = "abcdefghijklmnopqrstuvwxyz";

    /** ? The uppercase alphabet { A, B, C, ..., Z }. */
    public static final String UPPERCASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    /**
     * ?.
     * 
     * @see org.apache.commons.lang3.RandomStringUtils#randomAlphanumeric(int)
     */
    public static final String DECIMAL_AND_LETTERS = UPPERCASE + LOWERCASE + DECIMAL;

    /**
     * ??,?.
     * 
     * <p>
     * ???,{@link com.feilong.core.util.RandomUtil#createRandomFromString(String, int)}
     * </p>
     * 
     * <p>
     * /?:
     * </p>
     * 
     * <ul>
     * <li> 1  ? l</li>
     * <li> 0  ? o</li>
     * </ul>
     * 
     * <p>
     *  :23456789abcdefghijkmnpqrstuvwxyz
     * </p>
     * 
     * @see com.feilong.core.util.RandomUtil#createRandomFromString(String, int)
     * @see com.feilong.core.util.RandomUtil#createRandomFromString(String, int, int)
     */
    public static final String DECIMAL_AND_LOWERCASE_LETTERS_DISTINGUISHABLE = "23456789abcdefghijkmnpqrstuvwxyz";

    /** Don't let anyone instantiate this class. */
    private Alphabet() {
        //AssertionError?. ?????. ???.
        //see Effective Java 2nd
        throw new AssertionError("No " + getClass().getName() + " instances for you!");
    }
}