001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019 package org.apache.shiro.util;
020
021 /**
022 * Internal helper class used to find the Java/JDK version
023 * that Shiro is operating within, to allow for automatically
024 * adapting to the present platform's capabilities.
025 *
026 * <p>Note that Shiro does not support 1.2 or earlier JVMs - only 1.3 and later.
027 *
028 * <p><em>This class was borrowed and heavily based upon a nearly identical version found in
029 * the <a href="http://www.springframework.org/">Spring Framework</a>, with minor modifications.
030 * The original author names and copyright (Apache 2.0) has been left in place. A special
031 * thanks to Rod Johnson, Juergen Hoeller, and Rick Evans for making this available.</em>
032 *
033 * @author Rod Johnson
034 * @author Juergen Hoeller
035 * @author Rick Evans
036 * @author Les Hazlewood
037 * @since 0.2
038 */
039 public abstract class JavaEnvironment {
040
041 /**
042 * Constant identifying the 1.3.x JVM (JDK 1.3).
043 */
044 public static final int JAVA_13 = 0;
045
046 /**
047 * Constant identifying the 1.4.x JVM (J2SE 1.4).
048 */
049 public static final int JAVA_14 = 1;
050
051 /**
052 * Constant identifying the 1.5 JVM (Java 5).
053 */
054 public static final int JAVA_15 = 2;
055
056 /**
057 * Constant identifying the 1.6 JVM (Java 6).
058 */
059 public static final int JAVA_16 = 3;
060
061 /**
062 * Constant identifying the 1.7 JVM.
063 */
064 public static final int JAVA_17 = 4;
065
066 /** The virtual machine version, i.e. <code>System.getProperty("java.version");</code>. */
067 private static final String version;
068
069 /**
070 * The virtual machine <em>major</em> version. For example, with a <code>version</code> of
071 * <code>1.5.6_10</code>, this would be <code>1.5</code>
072 */
073 private static final int majorVersion;
074
075 /**
076 * Static code initialization block that sets the
077 * <code>version</code> and <code>majorVersion</code> Class constants
078 * upon initialization.
079 */
080 static {
081 version = System.getProperty("java.version");
082 // version String should look like "1.4.2_10"
083 if (version.indexOf("1.7.") != -1) {
084 majorVersion = JAVA_17;
085 } else if (version.indexOf("1.6.") != -1) {
086 majorVersion = JAVA_16;
087 } else if (version.indexOf("1.5.") != -1) {
088 majorVersion = JAVA_15;
089 } else if (version.indexOf("1.4.") != -1) {
090 majorVersion = JAVA_14;
091 } else {
092 // else leave 1.3 as default (it's either 1.3 or unknown)
093 majorVersion = JAVA_13;
094 }
095 }
096
097
098 /**
099 * Return the full Java version string, as returned by
100 * <code>System.getProperty("java.version")</code>.
101 *
102 * @return the full Java version string
103 * @see System#getProperty(String)
104 */
105 public static String getVersion() {
106 return version;
107 }
108
109 /**
110 * Get the major version code. This means we can do things like
111 * <code>if (getMajorVersion() < JAVA_14)</code>.
112 *
113 * @return a code comparable to the JAVA_XX codes in this class
114 * @see #JAVA_13
115 * @see #JAVA_14
116 * @see #JAVA_15
117 * @see #JAVA_16
118 * @see #JAVA_17
119 */
120 public static int getMajorVersion() {
121 return majorVersion;
122 }
123
124 /**
125 * Convenience method to determine if the current JVM is at least Java 1.4.
126 *
127 * @return <code>true</code> if the current JVM is at least Java 1.4
128 * @see #getMajorVersion()
129 * @see #JAVA_14
130 * @see #JAVA_15
131 * @see #JAVA_16
132 * @see #JAVA_17
133 */
134 public static boolean isAtLeastVersion14() {
135 return getMajorVersion() >= JAVA_14;
136 }
137
138 /**
139 * Convenience method to determine if the current JVM is at least
140 * Java 1.5 (Java 5).
141 *
142 * @return <code>true</code> if the current JVM is at least Java 1.5
143 * @see #getMajorVersion()
144 * @see #JAVA_15
145 * @see #JAVA_16
146 * @see #JAVA_17
147 */
148 public static boolean isAtLeastVersion15() {
149 return getMajorVersion() >= JAVA_15;
150 }
151 }