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}