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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.shiro.util;
20  
21  /**
22   * Internal helper class used to find the Java/JDK version
23   * that Shiro is operating within, to allow for automatically
24   * adapting to the present platform's capabilities.
25   *
26   * <p>Note that Shiro does not support 1.2 or earlier JVMs - only 1.3 and later.
27   *
28   * <p><em>This class was borrowed and heavily based upon a nearly identical version found in
29   * the <a href="http://www.springframework.org/">Spring Framework</a>, with minor modifications.
30   * The original author names and copyright (Apache 2.0) has been left in place.  A special
31   * thanks to Rod Johnson, Juergen Hoeller, and Rick Evans for making this available.</em>
32   *
33   * @since 0.2
34   */
35  public abstract class JavaEnvironment {
36  
37      /**
38       * Constant identifying the 1.3.x JVM (JDK 1.3).
39       */
40      public static final int JAVA_13 = 0;
41  
42      /**
43       * Constant identifying the 1.4.x JVM (J2SE 1.4).
44       */
45      public static final int JAVA_14 = 1;
46  
47      /**
48       * Constant identifying the 1.5 JVM (Java 5).
49       */
50      public static final int JAVA_15 = 2;
51  
52      /**
53       * Constant identifying the 1.6 JVM (Java 6).
54       */
55      public static final int JAVA_16 = 3;
56  
57      /**
58       * Constant identifying the 1.7 JVM.
59       */
60      public static final int JAVA_17 = 4;
61  
62      /** The virtual machine version, i.e. <code>System.getProperty("java.version");</code>. */
63      private static final String version;
64  
65      /**
66       * The virtual machine <em>major</em> version.  For example, with a <code>version</code> of
67       * <code>1.5.6_10</code>, this would be <code>1.5</code>
68       */
69      private static final int majorVersion;
70  
71      /**
72       * Static code initialization block that sets the
73       * <code>version</code> and <code>majorVersion</code> Class constants
74       * upon initialization.
75       */
76      static {
77          version = System.getProperty("java.version");
78          // version String should look like "1.4.2_10"
79          if (version.indexOf("1.7.") != -1) {
80              majorVersion = JAVA_17;
81          } else if (version.indexOf("1.6.") != -1) {
82              majorVersion = JAVA_16;
83          } else if (version.indexOf("1.5.") != -1) {
84              majorVersion = JAVA_15;
85          } else if (version.indexOf("1.4.") != -1) {
86              majorVersion = JAVA_14;
87          } else {
88              // else leave 1.3 as default (it's either 1.3 or unknown)
89              majorVersion = JAVA_13;
90          }
91      }
92  
93  
94      /**
95       * Return the full Java version string, as returned by
96       * <code>System.getProperty("java.version")</code>.
97       *
98       * @return the full Java version string
99       * @see System#getProperty(String)
100      */
101     public static String getVersion() {
102         return version;
103     }
104 
105     /**
106      * Get the major version code. This means we can do things like
107      * <code>if (getMajorVersion() < JAVA_14)</code>.
108      *
109      * @return a code comparable to the JAVA_XX codes in this class
110      * @see #JAVA_13
111      * @see #JAVA_14
112      * @see #JAVA_15
113      * @see #JAVA_16
114      * @see #JAVA_17
115      */
116     public static int getMajorVersion() {
117         return majorVersion;
118     }
119 
120     /**
121      * Convenience method to determine if the current JVM is at least Java 1.4.
122      *
123      * @return <code>true</code> if the current JVM is at least Java 1.4
124      * @see #getMajorVersion()
125      * @see #JAVA_14
126      * @see #JAVA_15
127      * @see #JAVA_16
128      * @see #JAVA_17
129      */
130     public static boolean isAtLeastVersion14() {
131         return getMajorVersion() >= JAVA_14;
132     }
133 
134     /**
135      * Convenience method to determine if the current JVM is at least
136      * Java 1.5 (Java 5).
137      *
138      * @return <code>true</code> if the current JVM is at least Java 1.5
139      * @see #getMajorVersion()
140      * @see #JAVA_15
141      * @see #JAVA_16
142      * @see #JAVA_17
143      */
144     public static boolean isAtLeastVersion15() {
145         return getMajorVersion() >= JAVA_15;
146     }
147 
148     /**
149      * Convenience method to determine if the current JVM is at least
150      * Java 1.6 (Java 6).
151      *
152      * @return <code>true</code> if the current JVM is at least Java 1.6
153      * @see #getMajorVersion()
154      * @see #JAVA_15
155      * @see #JAVA_16
156      * @see #JAVA_17
157      *
158      * @since 1.2
159      */
160     public static boolean isAtLeastVersion16() {
161         return getMajorVersion() >= JAVA_16;
162     }
163 }