    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.lang3;
    018
    019import org.apache.commons.lang3.math.NumberUtils;
    020
    021/**
    022 * <p>An enum representing all the versions of the Java specification.
    023 * This is intended to mirror available values from the
    024 * <em>java.specification.version</em> System property. </p>
    025 *
    026 * @since 3.0
    027 */
    028public enum JavaVersion {
    029
    030    /**
    031     * The Java version reported by Android. This is not an official Java version number.
    032     */
    033    JAVA_0_9(1.5f, "0.9"),
    034
    035    /**
    036     * Java 1.1.
    037     */
    038    JAVA_1_1(1.1f, "1.1"),
    039
    040    /**
    041     * Java 1.2.
    042     */
    043    JAVA_1_2(1.2f, "1.2"),
    044
    045    /**
    046     * Java 1.3.
    047     */
    048    JAVA_1_3(1.3f, "1.3"),
    049
    050    /**
    051     * Java 1.4.
    052     */
    053    JAVA_1_4(1.4f, "1.4"),
    054
    055    /**
    056     * Java 1.5.
    057     */
    058    JAVA_1_5(1.5f, "1.5"),
    059
    060    /**
    061     * Java 1.6.
    062     */
    063    JAVA_1_6(1.6f, "1.6"),
    064
    065    /**
    066     * Java 1.7.
    067     */
    068    JAVA_1_7(1.7f, "1.7"),
    069
    070    /**
    071     * Java 1.8.
    072     */
    073    JAVA_1_8(1.8f, "1.8"),
    074
    075    /**
    076     * Java 1.9.
    077     *
    078     * @deprecated As of release 3.5, replaced by {@link #JAVA_9}
    079     */
    080    @Deprecated
    081    JAVA_1_9(9.0f, "9"),
    082
    083    /**
    084     * Java 9
    085     *
    086     * @since 3.5
    087     */
    088    JAVA_9(9.0f, "9"),
    089
    090    /**
    091     * Java 10
    092     *
    093     * @since 3.7
    094     */
    095    JAVA_10(10.0f, "10"),
    096
    097    /**
    098     * Java 11
    099     *
    100     * @since 3.8
    101     */
    102    JAVA_11(11.0f, "11"),
    103
    104    /**
    105     * Java 12
    106     *
    107     * @since 3.9
    108     */
    109    JAVA_12(12.0f, "12"),
    110
    111    /**
    112     * Java 13
    113     *
    114     * @since 3.9
    115     */
    116    JAVA_13(13.0f, "13"),
    117
    118    /**
    119     * The most recent java version. Mainly introduced to avoid to break when a new version of Java is used.
    120     */
    121    JAVA_RECENT(maxVersion(), Float.toString(maxVersion()));
    122
    123    /**
    124     * The float value.
    125     */
    126    private final float value;
    127
    128    /**
    129     * The standard name.
    130     */
    131    private final String name;
    132
    133    /**
    134     * Constructor.
    135     *
    136     * @param value  the float value
    137     * @param name  the standard name, not null
    138     */
    139    JavaVersion(final float value, final String name) {
    140        this.value = value;
    141        this.name = name;
    142    }
    143
    144    //-----------------------------------------------------------------------
    145    /**
    146     * <p>Whether this version of Java is at least the version of Java passed in.</p>
    147     *
    148     * <p>For example:<br>
    149     *  {@code myVersion.atLeast(JavaVersion.JAVA_1_4)}<p>
    150     *
    151     * @param requiredVersion  the version to check against, not null
    152     * @return true if this version is equal to or greater than the specified version
    153     */
    154    public boolean atLeast(final JavaVersion requiredVersion) {
    155        return this.value >= requiredVersion.value;
    156    }
    157
    158    //-----------------------------------------------------------------------
    159    /**
    160     * <p>Whether this version of Java is at most the version of Java passed in.</p>
    161     *
    162     * <p>For example:<br>
    163     *  {@code myVersion.atMost(JavaVersion.JAVA_1_4)}<p>
    164     *
    165     * @param requiredVersion  the version to check against, not null
    166     * @return true if this version is equal to or greater than the specified version
    167     * @since 3.9
    168     */
    169    public boolean atMost(final JavaVersion requiredVersion) {
    170        return this.value <= requiredVersion.value;
    171    }
    172
    173    /**
    174     * Transforms the given string with a Java version number to the
    175     * corresponding constant of this enumeration class. This method is used
    176     * internally.
    177     *
    178     * @param nom the Java version as string
    179     * @return the corresponding enumeration constant or <b>null</b> if the
    180     * version is unknown
    181     */
    182    // helper for static importing
    183    static JavaVersion getJavaVersion(final String nom) {
    184        return get(nom);
    185    }
    186
    187    /**
    188     * Transforms the given string with a Java version number to the
    189     * corresponding constant of this enumeration class. This method is used
    190     * internally.
    191     *
    192     * @param nom the Java version as string
    193     * @return the corresponding enumeration constant or <b>null</b> if the
    194     * version is unknown
    195     */
    196    static JavaVersion get(final String nom) {
    197        if (nom == null) {
    198            return null;
    199        } else if ("0.9".equals(nom)) {
    200            return JAVA_0_9;
    201        } else if ("1.1".equals(nom)) {
    202            return JAVA_1_1;
    203        } else if ("1.2".equals(nom)) {
    204            return JAVA_1_2;
    205        } else if ("1.3".equals(nom)) {
    206            return JAVA_1_3;
    207        } else if ("1.4".equals(nom)) {
    208            return JAVA_1_4;
    209        } else if ("1.5".equals(nom)) {
    210            return JAVA_1_5;
    211        } else if ("1.6".equals(nom)) {
    212            return JAVA_1_6;
    213        } else if ("1.7".equals(nom)) {
    214            return JAVA_1_7;
    215        } else if ("1.8".equals(nom)) {
    216            return JAVA_1_8;
    217        } else if ("9".equals(nom)) {
    218            return JAVA_9;
    219        } else if ("10".equals(nom)) {
    220            return JAVA_10;
    221        } else if ("11".equals(nom)) {
    222            return JAVA_11;
    223        } else if ("12".equals(nom)) {
    224            return JAVA_12;
    225        } else if ("13".equals(nom)) {
    226            return JAVA_13;
    227        }
    228        final float v = toFloatVersion(nom);
    229        if ((v - 1.) < 1.) { // then we need to check decimals > .9
    230            final int firstComma = Math.max(nom.indexOf('.'), nom.indexOf(','));
    231            final int end = Math.max(nom.length(), nom.indexOf(',', firstComma));
    232            if (Float.parseFloat(nom.substring(firstComma + 1, end)) > .9f) {
    233                return JAVA_RECENT;
    234            }
    235        } else if (v > 10) {
    236            return JAVA_RECENT;
    237        }
    238        return null;
    239    }
    240
    241    //-----------------------------------------------------------------------
    242    /**
    243     * <p>The string value is overridden to return the standard name.</p>
    244     *
    245     * <p>For example, {@code "1.5"}.</p>
    246     *
    247     * @return the name, not null
    248     */
    249    @Override
    250    public String toString() {
    251        return name;
    252    }
    253
    254    /**
    255     * Gets the Java Version from the system or 99.0 if the {@code java.specification.version} system property is not set.
    256     *
    257     * @return the value of {@code java.specification.version} system property or 99.0 if it is not set.
    258     */
    259    private static float maxVersion() {
    260        final float v = toFloatVersion(System.getProperty("java.specification.version", "99.0"));
    261        if (v > 0) {
    262            return v;
    263        }
    264        return 99f;
    265    }
    266
    267    /**
    268     * Parses a float value from a String.
    269     *
    270     * @param value the String to parse.
    271     * @return the float value represented by the string or -1 if the given String can not be parsed.
    272     */
    273    private static float toFloatVersion(final String value) {
    274        final int defaultReturnValue = -1;
    275        if (value.contains(".")) {
    276            final String[] toParse = value.split("\\.");
    277            if (toParse.length >= 2) {
    278                return NumberUtils.toFloat(toParse[0] + '.' + toParse[1], defaultReturnValue);
    279            }
    280        } else {
    281            return NumberUtils.toFloat(value, defaultReturnValue);
    282        }
    283        return defaultReturnValue;
    284    }
    285}