com.jkoolcloud.tnt4j.streams.utils.Range.java Source code

Introduction

Here is the source code for com.jkoolcloud.tnt4j.streams.utils.Range.java

Source

/*
 * Copyright 2014-2017 JKOOL, LLC.
 *
 * 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.jkoolcloud.tnt4j.streams.utils;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;

/**
 * Base class defining numeric range.
 *
 * @version $Revision: 1 $
 *
 * @see DoubleRange
 * @see IntRange
 */
public abstract class Range<T extends Number> {
    /**
     * Constant defining number minus sign RegEx.
     */
    public static final String NEGATIVE_REGEX = "-?"; // NON-NLS
    /**
     * Constant defining integer number RegEx.
     */
    public static final String INT_REGEX = "(\\d)+"; // NON-NLS
    /**
     * Constant defining double number RegEx.
     */
    public static final String DOUBLE_REGEX = INT_REGEX + "(\\.)?(\\d)*"; // NON-NLS

    /**
     * Constant for range separator.
     */
    public static final String RANGE_SEPARATOR = ":"; // NON-NLS

    private T from;
    private T to;

    /**
     * Constructs a new Range.
     * 
     * @param from
     *            range lower bound
     * @param to
     *            range upper bound
     */
    protected Range(T from, T to) {
        this.from = from;
        this.to = to;
    }

    /**
     * Returns range lower bound.
     *
     * @return range lower bound
     */
    public T getFrom() {
        return from;
    }

    /**
     * Returns range upper bound.
     *
     * @return range upper bound
     */
    public T getTo() {
        return to;
    }

    /**
     * Checks if number value is in range bounds inclusive.
     *
     * @param num
     *            number value to check
     * @return flag indicating number is in range bounds inclusive
     */
    public abstract boolean inRange(T num);

    @Override
    public String toString() {
        return String.valueOf(from) + RANGE_SEPARATOR + String.valueOf(to);
    }

    @Override
    public int hashCode() {
        int result = from.hashCode();
        result = 31 * result + to.hashCode();
        return result;
    }

    /**
     * Parses string defining range values. Range definition separator is '{@value #RANGE_SEPARATOR}'.
     * 
     * @param rangeStr
     *            range definition string to parse
     * @param pattern
     *            RegEx pattern to use
     * @return string array where first element defines range lower bound and second element defines upper bound
     * @throws Exception
     *             if range string can't be parsed
     */
    protected static String[] parseRange(String rangeStr, Pattern pattern) throws Exception {
        String cs = StringUtils.trimToNull(rangeStr);
        if (StringUtils.isEmpty(cs)) {
            throw new IllegalArgumentException(
                    StreamsResources.getString(StreamsResources.RESOURCE_BUNDLE_NAME, "Range.range.string.empty"));
        }
        int rCharIdx = cs.indexOf(RANGE_SEPARATOR);

        String[] numStrs = new String[2];
        int si = 0;
        Matcher m = pattern.matcher(cs);
        while (m.find()) {
            String g = m.group();
            if (StringUtils.isNotEmpty(g)) {
                numStrs[si++] = g;
            }
            m.end();
        }

        String fromStr = null;
        String toStr = null;

        if (rCharIdx == -1) { // no range separator symbol found - unary range
            fromStr = numStrs.length > 0 ? numStrs[0] : null;
            toStr = fromStr;
        } else {
            if (rCharIdx == 0) { // unbound low range
                toStr = numStrs.length > 0 ? numStrs[0] : null;
            } else if (rCharIdx == cs.length()) { // unbound high range
                fromStr = numStrs.length > 0 ? numStrs[0] : null;
            } else { // bounded range
                fromStr = numStrs.length > 0 ? numStrs[0] : null;
                toStr = numStrs.length > 1 ? numStrs[1] : null;
            }
        }

        numStrs[0] = fromStr;
        numStrs[1] = toStr;

        return numStrs;
    }
}