https://ant.apache.org/: master POM (The Apache Software Foundation) 
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 *  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
 *
 *      https://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
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 *
 */
package org.apache.tools.ant.util;

import java.util.StringTokenizer;
import java.util.stream.Collectors;
import java.util.stream.IntStream;


Utility class to contain version numbers in "Dewey Decimal"
syntax.  Numbers in the "Dewey Decimal" syntax consist of positive
decimal integers separated by periods ".".  For example, "2.0" or
"1.2.3.4.5.6.7".  This allows an extensible number to be used to
represent major, minor, micro, etc versions.  The version number
must begin with a number.

/**
 * Utility class to contain version numbers in "Dewey Decimal"
 * syntax.  Numbers in the "Dewey Decimal" syntax consist of positive
 * decimal integers separated by periods ".".  For example, "2.0" or
 * "1.2.3.4.5.6.7".  This allows an extensible number to be used to
 * represent major, minor, micro, etc versions.  The version number
 * must begin with a number.
 *
 */
public class DeweyDecimal implements Comparable<DeweyDecimal> {

    
Array of components that make up DeweyDecimal 
/** Array of components that make up DeweyDecimal */
    private final int[] components;

    
Construct a DeweyDecimal from an array of integer components.

Params:
  • components – an array of integer components.
/**
     * Construct a DeweyDecimal from an array of integer components.
     *
     * @param components an array of integer components.
     */
    public DeweyDecimal(final int[] components) {
        this.components = new int[components.length];
        System.arraycopy(components, 0, this.components, 0, components.length);
    }

    
Construct a DeweyDecimal from string in DeweyDecimal format.

Params:
  • string – the string in dewey decimal format
Throws:
/**
     * Construct a DeweyDecimal from string in DeweyDecimal format.
     *
     * @param string the string in dewey decimal format
     * @exception NumberFormatException if string is malformed
     */
    public DeweyDecimal(final String string)
        throws NumberFormatException {
        final StringTokenizer tokenizer = new StringTokenizer(string, ".", true);
        final int size = tokenizer.countTokens();

        components = new int[(size + 1) / 2];

        for (int i = 0; i < components.length; i++) {
            final String component = tokenizer.nextToken();
            if (component.isEmpty()) {
                throw new NumberFormatException("Empty component in string");
            }

            components[i] = Integer.parseInt(component);

            //Strip '.' token
            if (tokenizer.hasMoreTokens()) {
                tokenizer.nextToken();

                //If it ended in a dot, throw an exception
                if (!tokenizer.hasMoreTokens()) {
                    throw new NumberFormatException("DeweyDecimal ended in a '.'");
                }
            }
        }
    }

    
Return number of components in DeweyDecimal.

Returns:the number of components in dewey decimal
/**
     * Return number of components in <code>DeweyDecimal</code>.
     *
     * @return the number of components in dewey decimal
     */
    public int getSize() {
        return components.length;
    }

    
Return the component at specified index.

Params:
  • index – the index of components
Returns:the value of component at index
/**
     * Return the component at specified index.
     *
     * @param index the index of components
     * @return the value of component at index
     */
    public int get(final int index) {
        return components[index];
    }

    
Return true if this DeweyDecimal is
equal to the other DeweyDecimal.

Params:
  • other – the other DeweyDecimal
Returns:true if equal to other DeweyDecimal, false otherwise
/**
     * Return <code>true</code> if this <code>DeweyDecimal</code> is
     * equal to the other <code>DeweyDecimal</code>.
     *
     * @param other the other DeweyDecimal
     * @return true if equal to other DeweyDecimal, false otherwise
     */
    public boolean isEqual(final DeweyDecimal other) {
        final int max = Math.max(other.components.length, components.length);

        for (int i = 0; i < max; i++) {
            final int component1 = (i < components.length) ? components[i] : 0;
            final int component2 = (i < other.components.length) ? other.components[i] : 0;

            if (component2 != component1) {
                return false;
            }
        }

        return true; // Exact match
    }

    
Return true if this DeweyDecimal is
less than the other DeweyDecimal.

Params:
  • other – the other DeweyDecimal
Returns:true if less than other DeweyDecimal, false otherwise
/**
     * Return <code>true</code> if this <code>DeweyDecimal</code> is
     * less than the other <code>DeweyDecimal</code>.
     *
     * @param other the other DeweyDecimal
     * @return true if less than other DeweyDecimal, false otherwise
     */
    public boolean isLessThan(final DeweyDecimal other) {
        return !isGreaterThanOrEqual(other);
    }

    
Return true if this DeweyDecimal is
less than or equal to the other DeweyDecimal.

Params:
  • other – the other DeweyDecimal
Returns:true if less than or equal to other DeweyDecimal, false otherwise
/**
     * Return <code>true</code> if this <code>DeweyDecimal</code> is
     * less than or equal to the other <code>DeweyDecimal</code>.
     *
     * @param other the other DeweyDecimal
     * @return true if less than or equal to other DeweyDecimal, false otherwise
     */
    public boolean isLessThanOrEqual(final DeweyDecimal other) {
        return !isGreaterThan(other);
    }

    
Return true if this DeweyDecimal is
greater than the other DeweyDecimal.

Params:
  • other – the other DeweyDecimal
Returns:true if greater than other DeweyDecimal, false otherwise
/**
     * Return <code>true</code> if this <code>DeweyDecimal</code> is
     * greater than the other <code>DeweyDecimal</code>.
     *
     * @param other the other DeweyDecimal
     * @return true if greater than other DeweyDecimal, false otherwise
     */
    public boolean isGreaterThan(final DeweyDecimal other) {
        final int max = Math.max(other.components.length, components.length);

        for (int i = 0; i < max; i++) {
            final int component1 = (i < components.length) ? components[i] : 0;
            final int component2 = (i < other.components.length) ? other.components[i] : 0;

            if (component2 > component1) {
                return false;
            }
            if (component2 < component1) {
                return true;
            }
        }

        return false; // Exact match
    }

    
Return true if this DeweyDecimal is
greater than or equal to the other DeweyDecimal.

Params:
  • other – the other DeweyDecimal
Returns:true if greater than or equal to other DeweyDecimal, false otherwise
/**
     * Return <code>true</code> if this <code>DeweyDecimal</code> is
     * greater than or equal to the other <code>DeweyDecimal</code>.
     *
     * @param other the other DeweyDecimal
     * @return true if greater than or equal to other DeweyDecimal, false otherwise
     */
    public boolean isGreaterThanOrEqual(final DeweyDecimal other) {
        final int max = Math.max(other.components.length, components.length);

        for (int i = 0; i < max; i++) {
            final int component1 = (i < components.length) ? components[i] : 0;
            final int component2 = (i < other.components.length) ? other.components[i] : 0;

            if (component2 > component1) {
                return false;
            }
            if (component2 < component1) {
                return true;
            }
        }

        return true; // Exact match
    }

    
Return string representation of DeweyDecimal.

Returns:the string representation of DeweyDecimal.
/**
     * Return string representation of <code>DeweyDecimal</code>.
     *
     * @return the string representation of DeweyDecimal.
     */
    @Override public String toString() {
        return IntStream.of(components).mapToObj(Integer::toString)
            .collect(Collectors.joining("."));
    }

    
Compares this DeweyDecimal with another one.

Params:
  • other – another DeweyDecimal to compare with
See Also:
Returns:result
/**
     * Compares this DeweyDecimal with another one.
     *
     * @param other another DeweyDecimal to compare with
     * @return result
     * @see java.lang.Comparable#compareTo(Object)
     */
    @Override
    public int compareTo(DeweyDecimal other) {
        final int max = Math.max(other.components.length, components.length);
        for (int i = 0; i < max; i++) {
            final int component1 = (i < components.length) ? components[i] : 0;
            final int component2 = (i < other.components.length) ? other.components[i] : 0;
            if (component1 != component2) {
                return component1 - component2;
            }
        }
        return 0;
    }

    @Override public int hashCode() {
        return toString().hashCode();
    }

    @Override public boolean equals(Object o) {
        return o instanceof DeweyDecimal && isEqual((DeweyDecimal) o);
    }

}