    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 *      http://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 *
    039 * @version $Revision$
    040 */
    041public class Flags implements Serializable, Cloneable {
    042
    043    private static final long serialVersionUID = 8481587558770237995L;
    044
    045    /**
    046     * Represents the current flag state.
    047     */
    048    private long flags = 0;
    049
    050    /**
    051     * Create a new Flags object.
    052     */
    053    public Flags() {
    054        super();
    055    }
    056
    057    /**
    058     * Initialize a new Flags object with the given flags.
    059     *
    060     * @param flags collection of boolean flags to represent.
    061     */
    062    public Flags(long flags) {
    063        super();
    064        this.flags = flags;
    065    }
    066
    067    /**
    068     * Returns the current flags.
    069     *
    070     * @return collection of boolean flags represented.
    071     */
    072    public long getFlags() {
    073        return this.flags;
    074    }
    075
    076    /**
    077     * Tests whether the given flag is on.  If the flag is not a power of 2
    078     * (ie. 3) this tests whether the combination of flags is on.
    079     *
    080     * @param flag Flag value to check.
    081     *
    082     * @return whether the specified flag value is on.
    083     */
    084    public boolean isOn(long flag) {
    085        return (this.flags & flag) == flag;
    086    }
    087
    088    /**
    089     * Tests whether the given flag is off.  If the flag is not a power of 2
    090     * (ie. 3) this tests whether the combination of flags is off.
    091     *
    092     * @param flag Flag value to check.
    093     *
    094     * @return whether the specified flag value is off.
    095     */
    096    public boolean isOff(long flag) {
    097        return (this.flags & flag) == 0;
    098    }
    099
    100    /**
    101     * Turns on the given flag.  If the flag is not a power of 2 (ie. 3) this
    102     * turns on multiple flags.
    103     *
    104     * @param flag Flag value to turn on.
    105     */
    106    public void turnOn(long flag) {
    107        this.flags |= flag;
    108    }
    109
    110    /**
    111     * Turns off the given flag.  If the flag is not a power of 2 (ie. 3) this
    112     * turns off multiple flags.
    113     *
    114     * @param flag Flag value to turn off.
    115     */
    116    public void turnOff(long flag) {
    117        this.flags &= ~flag;
    118    }
    119
    120    /**
    121     * Turn off all flags.
    122     */
    123    public void turnOffAll() {
    124        this.flags = 0;
    125    }
    126
    127    /**
    128     * Turn off all flags.  This is a synonym for <code>turnOffAll()</code>.
    129     * @since Validator 1.1.1
    130     */
    131    public void clear() {
    132        this.flags = 0;
    133    }
    134
    135    /**
    136     * Turn on all 64 flags.
    137     */
    138    public void turnOnAll() {
    139        this.flags = 0xFFFFFFFFFFFFFFFFl;
    140    }
    141
    142    /**
    143     * Clone this Flags object.
    144     *
    145     * @return a copy of this object.
    146     * @see java.lang.Object#clone()
    147     */
    148    @Override
    149    public Object clone() {
    150        try {
    151            return super.clone();
    152        } catch(CloneNotSupportedException e) {
    153            throw new RuntimeException("Couldn't clone Flags object.");
    154        }
    155    }
    156
    157    /**
    158     * Tests if two Flags objects are in the same state.
    159     * @param obj object being tested
    160     * @see java.lang.Object#equals(java.lang.Object)
    161     *
    162     * @return whether the objects are equal.
    163     */
    164    @Override
    165    public boolean equals(Object obj) {
    166        if (!(obj instanceof Flags)) {
    167            return false;
    168        }
    169
    170        if (obj == this) {
    171            return true;
    172        }
    173
    174        Flags f = (Flags) obj;
    175
    176        return this.flags == f.flags;
    177    }
    178
    179    /**
    180     * The hash code is based on the current state of the flags.
    181     * @see java.lang.Object#hashCode()
    182     *
    183     * @return the hash code for this object.
    184     */
    185    @Override
    186    public int hashCode() {
    187        return (int) this.flags;
    188    }
    189
    190    /**
    191     * Returns a 64 length String with the first flag on the right and the
    192     * 64th flag on the left.  A 1 indicates the flag is on, a 0 means it's
    193     * off.
    194     *
    195     * @return string representation of this object.
    196     */
    197    @Override
    198    public String toString() {
    199        StringBuilder bin = new StringBuilder(Long.toBinaryString(this.flags));
    200        for (int i = 64 - bin.length(); i > 0; i--) { // CHECKSTYLE IGNORE MagicNumber
    201            bin.insert(0, "0");
    202        }
    203        return bin.toString();
    204    }
    205
    206}