1 package org.codehaus.mojo.jaxb2.shared;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 /**
23 * Helper to extract the runtime Java version from the System.properties.
24 *
25 * @author <a href="mailto:lj@jguru.se">Lennart Jörelid</a>
26 * @since 2.4
27 */
28 public final class JavaVersion {
29
30 private static final String JAVA_VERSION_PROPERTY = "java.specification.version";
31
32 /**
33 * Retrieves the major java runtime version as an integer.
34 *
35 * @return the major java runtime version as an integer.
36 */
37 public static int getJavaMajorVersion() {
38
39 final String[] versionElements = System.getProperty(JAVA_VERSION_PROPERTY).split("\\.");
40 final int[] versionNumbers = new int[versionElements.length];
41
42 for (int i = 0; i < versionElements.length; i++) {
43 try {
44 versionNumbers[i] = Integer.parseInt(versionElements[i]);
45 } catch (NumberFormatException e) {
46 versionNumbers[i] = 0;
47 }
48 }
49
50 /*
51 Java versions 1 - 8 (i.e. jdk 1.1 through 1.8) yields the structure 1.8
52 Java versions 9 - yields the structure 10
53
54 JDK 10
55 ======
56 [java.specification.version]: 10
57
58 JDK 8
59 =====
60 [java.specification.version]: 1.8
61
62 JDK 7
63 =====
64 [java.specification.version]: 1.7
65 */
66 return versionNumbers[0] == 1 ? versionNumbers[1] : versionNumbers[0];
67 }
68
69 /**
70 * Checks if the runtime java version is JDK 8 or lower.
71 *
72 * @return true if the runtime java version is JDK 8 or lower.
73 */
74 public static boolean isJdk8OrLower() {
75 return getJavaMajorVersion() <= 8;
76 }
77 }