    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.validator.util;
    018
    019import java.io.Serializable;
    020
    021/**
    022 * Represents a collection of 64 boolean (on/off) flags.  Individual flags
    023 * are represented by powers of 2.  For example,<br>
    024 * Flag 1 = 1<br>
    025 * Flag 2 = 2<br>
    026 * Flag 3 = 4<br>
    027 * Flag 4 = 8<br><br>
    028 * or using shift operator to make numbering easier:<br>
    029 * Flag 1 = 1 &lt;&lt; 0<br>
    030 * Flag 2 = 1 &lt;&lt; 1<br>
    031 * Flag 3 = 1 &lt;&lt; 2<br>
    032 * Flag 4 = 1 &lt;&lt; 3<br>
    033 *
    034 * <p>
    035 * There cannot be a flag with a value of 3 because that represents Flag 1
    036 * and Flag 2 both being on/true.
    037 * </p>
    038 */
    039public class Flags implements Serializable, Cloneable {
    040
    041    private static final long serialVersionUID = 8481587558770237995L;
    042
    043    /**
    044     * Represents the current flag state.
    045     */
    046    private long flags;
    047
    048    /**
    049     * Create a new Flags object.
    050     */
    051    public Flags() {
    052    }
    053
    054    /**
    055     * Initialize a new Flags object with the given flags.
    056     *
    057     * @param flags collection of boolean flags to represent.
    058     */
    059    public Flags(final long flags) {
    060        this.flags = flags;
    061    }
    062
    063    /**
    064     * Turn off all flags.  This is a synonym for {@code turnOffAll()}.
    065     *
    066     * @since 1.1.1
    067     */
    068    public void clear() {
    069        flags = 0;
    070    }
    071
    072    /**
    073     * Clone this Flags object.
    074     *
    075     * @return A copy of this object.
    076     * @see Object#clone()
    077     */
    078    @Override
    079    public Object clone() {
    080        try {
    081            return super.clone();
    082        } catch (final CloneNotSupportedException e) {
    083            throw new UnsupportedOperationException("Couldn't clone Flags object.", e);
    084        }
    085    }
    086
    087    /**
    088     * Tests if two Flags objects are in the same state.
    089     *
    090     * @param obj object being tested
    091     * @see Object#equals(Object)
    092     * @return whether the objects are equal.
    093     */
    094    @Override
    095    public boolean equals(final Object obj) {
    096        if (this == obj) {
    097            return true;
    098        }
    099        if (!(obj instanceof Flags)) {
    100            return false;
    101        }
    102        final Flags other = (Flags) obj;
    103        return flags == other.flags;
    104    }
    105
    106    /**
    107     * Returns the current flags.
    108     *
    109     * @return collection of boolean flags represented.
    110     */
    111    public long getFlags() {
    112        return flags;
    113    }
    114
    115    /**
    116     * The hash code is based on the current state of the flags.
    117     *
    118     * @see Object#hashCode()
    119     * @return The hash code for this object.
    120     */
    121    @Override
    122    public int hashCode() {
    123        return (int) flags;
    124    }
    125
    126    /**
    127     * Tests whether the given flag is off. If the flag is not a power of 2
    128     * (for example, 3) this tests whether the combination of flags is off.
    129     *
    130     * @param flag Flag value to check.
    131     * @return whether the specified flag value is off.
    132     */
    133    public boolean isOff(final long flag) {
    134        return (flags & flag) == 0;
    135    }
    136
    137    /**
    138     * Tests whether the given flag is on. If the flag is not a power of 2
    139     * (for example, 3) this tests whether the combination of flags is on.
    140     *
    141     * @param flag Flag value to check.
    142     * @return whether the specified flag value is on.
    143     */
    144    public boolean isOn(final long flag) {
    145        return (flags & flag) == flag;
    146    }
    147
    148    /**
    149     * Returns a 64 length String with the first flag on the right and the
    150     * 64th flag on the left. A 1 indicates the flag is on, a 0 means it's
    151     * off.
    152     *
    153     * @return string representation of this object.
    154     */
    155    @Override
    156    public String toString() {
    157        final StringBuilder bin = new StringBuilder(Long.toBinaryString(flags));
    158        for (int i = 64 - bin.length(); i > 0; i--) { // CHECKSTYLE IGNORE MagicNumber
    159            bin.insert(0, "0");
    160        }
    161        return bin.toString();
    162    }
    163
    164    /**
    165     * Turns off the given flag. If the flag is not a power of 2 (for example, 3) this
    166     * turns off multiple flags.
    167     *
    168     * @param flag Flag value to turn off.
    169     */
    170    public void turnOff(final long flag) {
    171        flags &= ~flag;
    172    }
    173
    174    /**
    175     * Turn off all flags.
    176     */
    177    public void turnOffAll() {
    178        flags = 0;
    179    }
    180
    181    /**
    182     * Turns on the given flag. If the flag is not a power of 2 (for example, 3) this
    183     * turns on multiple flags.
    184     *
    185     * @param flag Flag value to turn on.
    186     */
    187    public void turnOn(final long flag) {
    188        flags |= flag;
    189    }
    190
    191    /**
    192     * Turn on all 64 flags.
    193     */
    194    public void turnOnAll() {
    195        flags = 0xFFFFFFFFFFFFFFFFL;
    196    }
    197
    198}