    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     * Java 14
    120     *
    121     * @since 3.11
    122     */
    123    JAVA_14(14.0f, "14"),
    124
    125    /**
    126     * Java 15
    127     *
    128     * @since 3.11
    129     */
    130    JAVA_15(15.0f, "15"),
    131
    132    /**
    133     * Java 16
    134     *
    135     * @since 3.11
    136     */
    137    JAVA_16(16.0f, "16"),
    138
    139    /**
    140     * The most recent java version. Mainly introduced to avoid to break when a new version of Java is used.
    141     */
    142    JAVA_RECENT(maxVersion(), Float.toString(maxVersion()));
    143
    144    /**
    145     * The float value.
    146     */
    147    private final float value;
    148
    149    /**
    150     * The standard name.
    151     */
    152    private final String name;
    153
    154    /**
    155     * Constructor.
    156     *
    157     * @param value  the float value
    158     * @param name  the standard name, not null
    159     */
    160    JavaVersion(final float value, final String name) {
    161        this.value = value;
    162        this.name = name;
    163    }
    164
    165    //-----------------------------------------------------------------------
    166    /**
    167     * <p>Whether this version of Java is at least the version of Java passed in.</p>
    168     *
    169     * <p>For example:<br>
    170     *  {@code myVersion.atLeast(JavaVersion.JAVA_1_4)}<p>
    171     *
    172     * @param requiredVersion  the version to check against, not null
    173     * @return true if this version is equal to or greater than the specified version
    174     */
    175    public boolean atLeast(final JavaVersion requiredVersion) {
    176        return this.value >= requiredVersion.value;
    177    }
    178
    179    //-----------------------------------------------------------------------
    180    /**
    181     * <p>Whether this version of Java is at most the version of Java passed in.</p>
    182     *
    183     * <p>For example:<br>
    184     *  {@code myVersion.atMost(JavaVersion.JAVA_1_4)}<p>
    185     *
    186     * @param requiredVersion  the version to check against, not null
    187     * @return true if this version is equal to or greater than the specified version
    188     * @since 3.9
    189     */
    190    public boolean atMost(final JavaVersion requiredVersion) {
    191        return this.value <= requiredVersion.value;
    192    }
    193
    194    /**
    195     * Transforms the given string with a Java version number to the
    196     * corresponding constant of this enumeration class. This method is used
    197     * internally.
    198     *
    199     * @param nom the Java version as string
    200     * @return the corresponding enumeration constant or <b>null</b> if the
    201     * version is unknown
    202     */
    203    // helper for static importing
    204    static JavaVersion getJavaVersion(final String nom) {
    205        return get(nom);
    206    }
    207
    208    /**
    209     * Transforms the given string with a Java version number to the
    210     * corresponding constant of this enumeration class. This method is used
    211     * internally.
    212     *
    213     * @param nom the Java version as string
    214     * @return the corresponding enumeration constant or <b>null</b> if the
    215     * version is unknown
    216     */
    217    static JavaVersion get(final String nom) {
    218        if (nom == null) {
    219            return null;
    220        } else if ("0.9".equals(nom)) {
    221            return JAVA_0_9;
    222        } else if ("1.1".equals(nom)) {
    223            return JAVA_1_1;
    224        } else if ("1.2".equals(nom)) {
    225            return JAVA_1_2;
    226        } else if ("1.3".equals(nom)) {
    227            return JAVA_1_3;
    228        } else if ("1.4".equals(nom)) {
    229            return JAVA_1_4;
    230        } else if ("1.5".equals(nom)) {
    231            return JAVA_1_5;
    232        } else if ("1.6".equals(nom)) {
    233            return JAVA_1_6;
    234        } else if ("1.7".equals(nom)) {
    235            return JAVA_1_7;
    236        } else if ("1.8".equals(nom)) {
    237            return JAVA_1_8;
    238        } else if ("9".equals(nom)) {
    239            return JAVA_9;
    240        } else if ("10".equals(nom)) {
    241            return JAVA_10;
    242        } else if ("11".equals(nom)) {
    243            return JAVA_11;
    244        } else if ("12".equals(nom)) {
    245            return JAVA_12;
    246        } else if ("13".equals(nom)) {
    247            return JAVA_13;
    248        } else if ("14".equals(nom)) {
    249            return JAVA_14;
    250        } else if ("15".equals(nom)) {
    251            return JAVA_15;
    252        } else if ("16".equals(nom)) {
    253            return JAVA_16;
    254        }
    255        final float v = toFloatVersion(nom);
    256        if ((v - 1.) < 1.) { // then we need to check decimals > .9
    257            final int firstComma = Math.max(nom.indexOf('.'), nom.indexOf(','));
    258            final int end = Math.max(nom.length(), nom.indexOf(',', firstComma));
    259            if (Float.parseFloat(nom.substring(firstComma + 1, end)) > .9f) {
    260                return JAVA_RECENT;
    261            }
    262        } else if (v > 10) {
    263            return JAVA_RECENT;
    264        }
    265        return null;
    266    }
    267
    268    //-----------------------------------------------------------------------
    269    /**
    270     * <p>The string value is overridden to return the standard name.</p>
    271     *
    272     * <p>For example, {@code "1.5"}.</p>
    273     *
    274     * @return the name, not null
    275     */
    276    @Override
    277    public String toString() {
    278        return name;
    279    }
    280
    281    /**
    282     * Gets the Java Version from the system or 99.0 if the {@code java.specification.version} system property is not set.
    283     *
    284     * @return the value of {@code java.specification.version} system property or 99.0 if it is not set.
    285     */
    286    private static float maxVersion() {
    287        final float v = toFloatVersion(System.getProperty("java.specification.version", "99.0"));
    288        if (v > 0) {
    289            return v;
    290        }
    291        return 99f;
    292    }
    293
    294    /**
    295     * Parses a float value from a String.
    296     *
    297     * @param value the String to parse.
    298     * @return the float value represented by the string or -1 if the given String can not be parsed.
    299     */
    300    private static float toFloatVersion(final String value) {
    301        final int defaultReturnValue = -1;
    302        if (value.contains(".")) {
    303            final String[] toParse = value.split("\\.");
    304            if (toParse.length >= 2) {
    305                return NumberUtils.toFloat(toParse[0] + '.' + toParse[1], defaultReturnValue);
    306            }
    307        } else {
    308            return NumberUtils.toFloat(value, defaultReturnValue);
    309        }
    310        return defaultReturnValue;
    311    }
    312}