< prev index next >
jdk/src/java.base/share/classes/java/lang/Runtime.java
Print this page
@@ -1,7 +1,7 @@
/*
- * Copyright (c) 1995, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
@@ -24,13 +24,25 @@
*/
package java.lang;
import java.io.*;
+import java.math.BigInteger;
+import java.util.AbstractList;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.util.RandomAccess;
import java.util.StringTokenizer;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
+import sun.security.action.GetPropertyAction;
/**
* Every Java application has a single instance of class
* {@code Runtime} that allows the application to interface with
* the environment in which the application is running. The current
@@ -44,10 +56,12 @@
*/
public class Runtime {
private static final Runtime currentRuntime = new Runtime();
+ private static Version version;
+
/**
* Returns the runtime object associated with the current Java application.
* Most of the methods of class {@code Runtime} are instance
* methods and must be invoked with respect to the current runtime object.
*
@@ -915,6 +929,593 @@
@Deprecated(since="1.1", forRemoval=true)
public OutputStream getLocalizedOutputStream(OutputStream out) {
return out;
}
+ /**
+ * Returns the version of the Java Runtime Environment as a {@link
+ * Runtime.Version}.
+ *
+ * @return the {@link Runtime.Version} of the Java Runtime Environment
+ *
+ * @since 9
+ */
+ public static Version version() {
+ if (version == null) {
+ version = Version.parse(
+ GetPropertyAction.privilegedGetProperty("java.runtime.version"));
+ }
+ return version;
+ }
+
+ /**
+ * A representation of a version string for an implemenation of the
+ * Java SE Platform. A version string contains a version number
+ * optionally followed by pre-release and build information.
+ *
+ * <h2><a name="verNum">Version numbers</a></h2>
+ *
+ * <p> A <em>version number</em>, {@code $VNUM}, is a non-empty sequence
+ * of elements separated by period characters (U+002E). An element is
+ * either zero, or a unsigned integer numeral without leading zeros. The
+ * final element in a version number must not be zero. The format is:
+ * </p>
+ *
+ * <blockquote><pre>
+ * ^[1-9][0-9]*(((\.0)*\.[1-9][0-9]*)*)*$
+ * </pre></blockquote>
+ *
+ * <p> The sequence may be of arbitrary length but the first three
+ * elements are assigned specific meanings, as follows:</p>
+ *
+ * <blockquote><pre>
+ * $MAJOR.$MINOR.$SECURITY
+ * </pre></blockquote>
+ *
+ * <ul>
+ *
+ * <li><p> <a name="major">{@code $MAJOR}</a> --- The major version
+ * number, incremented for a major release that contains significant new
+ * features as specified in a new edition of the Java SE Platform
+ * Specification, <em>e.g.</em>, <a
+ * href="https://jcp.org/en/jsr/detail?id=337">JSR 337</a> for
+ * Java SE 8. Features may be removed in a major release, given
+ * advance notice at least one major release ahead of time, and
+ * incompatible changes may be made when justified. The {@code $MAJOR}
+ * version number of JDK 8 is {@code 8}; the {@code $MAJOR} version
+ * number of JDK 9 is {@code 9}. When {@code $MAJOR} is incremented,
+ * all subsequent elements are removed. </p></li>
+ *
+ * <li><p> <a name="minor">{@code $MINOR}</a> --- The minor version
+ * number, incremented for a minor update release that may contain
+ * compatible bug fixes, revisions to standard APIs mandated by a <a
+ * href="https://jcp.org/en/procedures/jcp2#5.3">Maintenance Release</a>
+ * of the relevant Platform Specification, and implementation features
+ * outside the scope of that Specification such as new JDK-specific APIs,
+ * additional service providers, new garbage collectors, and ports to new
+ * hardware architectures. </p></li>
+ *
+ * <li><p> <a name="security">{@code $SECURITY}</a> --- The security
+ * level, incremented for a security update release that contains critical
+ * fixes including those necessary to improve security. {@code $SECURITY}
+ * is <strong>not</strong> reset when {@code $MINOR} is incremented. A
+ * higher value of {@code $SECURITY} for a given {@code $MAJOR} value,
+ * therefore, always indicates a more secure release, regardless of the
+ * value of {@code $MINOR}. </p></li>
+ *
+ * </ul>
+ *
+ * <p> The fourth and later elements of a version number are free for use
+ * by downstream consumers of this code base. Such a consumer may,
+ * <em>e.g.</em>, use the fourth element to identify patch releases which
+ * contain a small number of critical non-security fixes in addition to
+ * the security fixes in the corresponding security release. </p>
+ *
+ * <p> The version number does not include trailing zero elements;
+ * <em>i.e.</em>, {@code $SECURITY} is omitted if it has the value zero,
+ * and {@code $MINOR} is omitted if both {@code $MINOR} and {@code
+ * $SECURITY} have the value zero. </p>
+ *
+ * <p> The sequence of numerals in a version number is compared to another
+ * such sequence in numerical, pointwise fashion; <em>e.g.</em>, {@code
+ * 9.9.1} is less than {@code 9.10.3}. If one sequence is shorter than
+ * another then the missing elements of the shorter sequence are
+ * considered to be less than the corresponding elements of the longer
+ * sequence; <em>e.g.</em>, {@code 9.1.2} is less than {@code 9.1.2.1}.
+ * </p>
+ *
+ * <h2><a name="verStr">Version strings</a></h2>
+ *
+ * <p> A <em>version string</em>, {@code $VSTR}, consists of a version
+ * number {@code $VNUM}, as described above, optionally followed by
+ * pre-release and build information, in the format </p>
+ *
+ * <blockquote><pre>
+ * $VNUM(-$PRE)?(\+($BUILD)?(-$OPT)?)?
+ * </pre></blockquote>
+ *
+ * <p> where: </p>
+ *
+ * <ul>
+ *
+ * <li><p> <a name="pre">{@code $PRE}</a>, matching {@code ([a-zA-Z0-9]+)}
+ * --- A pre-release identifier. Typically {@code ea}, for a
+ * potentially unstable early-access release under active development,
+ * or {@code internal}, for an internal developer build.
+ *
+ * <li><p> <a name="build">{@code $BUILD}</a>, matching {@code
+ * (0|[1-9][0-9]*)} --- The build number, incremented for each promoted
+ * build. {@code $BUILD} is reset to {@code 1} when any portion of {@code
+ * $VNUM} is incremented. </p>
+ *
+ * <li><p> <a name="opt">{@code $OPT}</a>, matching {@code
+ * ([-a-zA-Z0-9\.]+)} --- Additional build information, if desired. In
+ * the case of an {@code internal} build this will often contain the date
+ * and time of the build. </p>
+ *
+ * </ul>
+ *
+ * <p> A version number {@code 10-ea} matches {@code $VNUM = "10"} and
+ * {@code $PRE = "ea"}. The version number {@code 10+-ea} matches
+ * {@code $VNUM = "10"} and {@code $OPT = "ea"}. </p>
+ *
+ * <p> When comparing two version strings, the value of {@code $OPT}, if
+ * present, may or may not be significant depending on the chosen
+ * comparison method. The comparison methods {@link #compareTo(Version)
+ * compareTo()} and {@link #compareToIgnoreOpt(Version)
+ * compareToIgnoreOpt()} should be used consistently with the
+ * corresponding methods {@link #equals(Object) equals()} and {@link
+ * #equalsIgnoreOpt(Object) equalsIgnoreOpt()}. </p>
+ *
+ * <p> A <em>short version string</em>, {@code $SVSTR}, often useful in
+ * less formal contexts, is a version number optionally followed by a
+ * pre-release identifier:
+ *
+ * <blockquote><pre>
+ * $VNUM(-$PRE)?
+ * </pre></blockquote>
+ *
+ * @since 9
+ */
+ public static class Version
+ implements Comparable<Version>
+ {
+ private final List<Integer> version;
+ private final Optional<String> pre;
+ private final Optional<Integer> build;
+ private final Optional<String> optional;
+
+
+ // $VNUM(-$PRE)?(\+($BUILD)?(\-$OPT)?)?
+ // RE limits the format of version strings
+ // ([1-9][0-9]*(?:(?:\.0)*\.[1-9][0-9]*)*)(?:-([a-zA-Z0-9]+))?(?:(\+)(0|[1-9][0-9]*)?)?(?:-([-a-zA-Z0-9.]+))?
+
+ private static final String VNUM
+ = "(?<VNUM>[1-9][0-9]*(?:(?:\\.0)*\\.[1-9][0-9]*)*)";
+ private static final String VNUM_GROUP = "VNUM";
+
+ private static final String PRE = "(?:-(?<PRE>[a-zA-Z0-9]+))?";
+ private static final String PRE_GROUP = "PRE";
+
+ private static final String BUILD
+ = "(?:(?<PLUS>\\+)(?<BUILD>0|[1-9][0-9]*)?)?";
+ private static final String PLUS_GROUP = "PLUS";
+ private static final String BUILD_GROUP = "BUILD";
+
+ private static final String OPT = "(?:-(?<OPT>[-a-zA-Z0-9.]+))?";
+ private static final String OPT_GROUP = "OPT";
+
+ private static final String VSTR_FORMAT
+ = "^" + VNUM + PRE + BUILD + OPT + "$";
+ private static final Pattern VSTR_PATTERN = Pattern.compile(VSTR_FORMAT);
+
+ /**
+ * Constructs a valid <a href="verStr">version string</a> containing
+ * a <a href="#verNum">version number</a> followed by pre-release and
+ * build information.
+ *
+ * @param s
+ * A string to be interpreted as a version
+ *
+ * @throws IllegalArgumentException
+ * If the given string cannot be interpreted as a valid
+ * version
+ *
+ * @throws NullPointerException
+ * If {@code s} is {@code null}
+ *
+ * @throws NumberFormatException
+ * If an element of the version number or the build number
+ * cannot be represented as an {@link Integer}
+ */
+ private Version(String s) {
+ if (s == null)
+ throw new NullPointerException();
+
+ Matcher m = VSTR_PATTERN.matcher(s);
+ if (!m.matches())
+ throw new IllegalArgumentException("Invalid version string: '"
+ + s + "'");
+
+ // $VNUM is a dot-separated list of integers of arbitrary length
+ List<Integer> list = new ArrayList<>();
+ for (String i : m.group(VNUM_GROUP).split("\\."))
+ list.add(Integer.parseInt(i));
+ version = Collections.unmodifiableList(list);
+
+ pre = Optional.ofNullable(m.group(PRE_GROUP));
+
+ String b = m.group(BUILD_GROUP);
+ // $BUILD is an integer
+ build = (b == null)
+ ? Optional.<Integer>empty()
+ : Optional.ofNullable(Integer.parseInt(b));
+
+ optional = Optional.ofNullable(m.group(OPT_GROUP));
+
+ // empty '+'
+ if ((m.group(PLUS_GROUP) != null) && !build.isPresent()) {
+ if (optional.isPresent()) {
+ if (pre.isPresent())
+ throw new IllegalArgumentException("'+' found with"
+ + " pre-release and optional components:'" + s
+ + "'");
+ } else {
+ throw new IllegalArgumentException("'+' found with neither"
+ + " build or optional components: '" + s + "'");
+ }
+ }
+ }
+
+ /**
+ * Parses the given string as a valid <a
+ * href="#verStr">version string</a> containing a <a
+ * href="#verNum">version number</a> followed by pre-release and
+ * build information.
+ *
+ * @param s
+ * A string to interpret as a version
+ *
+ * @throws IllegalArgumentException
+ * If the given string cannot be interpreted as a valid
+ * version
+ *
+ * @throws NullPointerException
+ * If the given string is {@code null}
+ *
+ * @throws NumberFormatException
+ * If an element of the version number or the build number
+ * cannot be represented as an {@link Integer}
+ *
+ * @return This version
+ */
+ public static Version parse(String s) {
+ return new Version(s);
+ }
+
+ /**
+ * Returns the <a href="#major">major</a> version number.
+ *
+ * @return The major version number
+ */
+ public int major() {
+ return version.get(0);
+ }
+
+ /**
+ * Returns the <a href="#minor">minor</a> version number or zero if it
+ * was not set.
+ *
+ * @return The minor version number or zero if it was not set
+ */
+ public int minor() {
+ return (version.size() > 1 ? version.get(1) : 0);
+ }
+
+ /**
+ * Returns the <a href="#security">security</a> version number or zero
+ * if it was not set.
+ *
+ * @return The security version number or zero if it was not set
+ */
+ public int security() {
+ return (version.size() > 2 ? version.get(2) : 0);
+ }
+
+ /**
+ * Returns an unmodifiable {@link java.util.List List} of the
+ * integer numerals contained in the <a href="#verNum">version
+ * number</a>. The {@code List} always contains at least one
+ * element corresponding to the <a href="#major">major version
+ * number</a>.
+ *
+ * @return An unmodifiable list of the integer numerals
+ * contained in the version number
+ */
+ public List<Integer> version() {
+ return version;
+ }
+
+ /**
+ * Returns the optional <a href="#pre">pre-release</a> information.
+ *
+ * @return The optional pre-release information as a String
+ */
+ public Optional<String> pre() {
+ return pre;
+ }
+
+ /**
+ * Returns the <a href="#build">build number</a>.
+ *
+ * @return The optional build number.
+ */
+ public Optional<Integer> build() {
+ return build;
+ }
+
+ /**
+ * Returns <a href="#opt">optional</a> additional identifying build
+ * information.
+ *
+ * @return Additional build information as a String
+ */
+ public Optional<String> optional() {
+ return optional;
+ }
+
+ /**
+ * Compares this version to another.
+ *
+ * <p> Each of the components in the <a href="#verStr">version</a> is
+ * compared in the follow order of precedence: version numbers,
+ * pre-release identifiers, build numbers, optional build information.
+ * </p>
+ *
+ * <p> Comparison begins by examining the sequence of version numbers.
+ * If one sequence is shorter than another, then the missing elements
+ * of the shorter sequence are considered to be less than the
+ * corresponding elements of the longer sequence. </p>
+ *
+ * <p> A version with a pre-release identifier is always considered to
+ * be less than a version without one. Pre-release identifiers are
+ * compared numerically when they consist only of digits, and
+ * lexicographically otherwise. Numeric identifiers are considered to
+ * be less than non-numeric identifiers. </p>
+ *
+ * <p> A version without a build number is always less than one with a
+ * build number; otherwise build numbers are compared numerically. </p>
+ *
+ * <p> The optional build information is compared lexicographically.
+ * During this comparison, a version with optional build information is
+ * considered to be greater than a version without one. </p>
+ *
+ * <p> A version is not comparable to any other type of object.
+ *
+ * @param ob
+ * The object to be compared
+ *
+ * @return A negative integer, zero, or a positive integer if this
+ * {@code Version} is less than, equal to, or greater than the
+ * given {@code Version}
+ *
+ * @throws NullPointerException
+ * If the given object is {@code null}
+ */
+ @Override
+ public int compareTo(Version ob) {
+ return compare(ob, false);
+ }
+
+ /**
+ * Compares this version to another disregarding optional build
+ * information.
+ *
+ * <p> Two versions are compared by examining the version string as
+ * described in {@link #compareTo(Version)} with the exception that the
+ * optional build information is always ignored. </p>
+ *
+ * <p> A version is not comparable to any other type of object.
+ *
+ * @param ob
+ * The object to be compared
+ *
+ * @return A negative integer, zero, or a positive integer if this
+ * {@code Version} is less than, equal to, or greater than the
+ * given {@code Version}
+ *
+ * @throws NullPointerException
+ * If the given object is {@code null}
+ */
+ public int compareToIgnoreOpt(Version ob) {
+ return compare(ob, true);
+ }
+
+ private int compare(Version ob, boolean ignoreOpt) {
+ if (ob == null)
+ throw new NullPointerException("Invalid argument");
+
+ int ret = compareVersion(ob);
+ if (ret != 0)
+ return ret;
+
+ ret = comparePre(ob);
+ if (ret != 0)
+ return ret;
+
+ ret = compareBuild(ob);
+ if (ret != 0)
+ return ret;
+
+ if (!ignoreOpt)
+ return compareOpt(ob);
+
+ return 0;
+ }
+
+ private int compareVersion(Version ob) {
+ int size = version.size();
+ int oSize = ob.version().size();
+ int min = Math.min(size, oSize);
+ for (int i = 0; i < min; i++) {
+ Integer val = version.get(i);
+ Integer oVal = ob.version().get(i);
+ if (val != oVal)
+ return val - oVal;
+ }
+ if (size != oSize)
+ return size - oSize;
+ return 0;
+ }
+
+ private int comparePre(Version ob) {
+ Optional<String> oPre = ob.pre();
+ if (!pre.isPresent()) {
+ if (oPre.isPresent())
+ return 1;
+ } else {
+ if (!oPre.isPresent())
+ return -1;
+ String val = pre.get();
+ String oVal = oPre.get();
+ if (val.matches("\\d+")) {
+ return (oVal.matches("\\d+")
+ ? (new BigInteger(val)).compareTo(new BigInteger(oVal))
+ : -1);
+ } else {
+ return (oVal.matches("\\d+")
+ ? 1
+ : val.compareTo(oVal));
+ }
+ }
+ return 0;
+ }
+
+ private int compareBuild(Version ob) {
+ Optional<Integer> oBuild = ob.build();
+ if (oBuild.isPresent()) {
+ return (build.isPresent()
+ ? build.get().compareTo(oBuild.get())
+ : 1);
+ } else if (build.isPresent()) {
+ return -1;
+ }
+ return 0;
+ }
+
+ private int compareOpt(Version ob) {
+ Optional<String> oOpt = ob.optional();
+ if (!optional.isPresent()) {
+ if (oOpt.isPresent())
+ return -1;
+ } else {
+ if (!oOpt.isPresent())
+ return 1;
+ return optional.get().compareTo(oOpt.get());
+ }
+ return 0;
+ }
+
+ /**
+ * Returns a string representation of this version.
+ *
+ * @return The version string
+ */
+ @Override
+ public String toString() {
+ StringBuilder sb
+ = new StringBuilder(version.stream()
+ .map(Object::toString)
+ .collect(Collectors.joining(".")));
+
+ pre.ifPresent(v -> sb.append("-").append(v));
+
+ if (build.isPresent()) {
+ sb.append("+").append(build.get());
+ if (optional.isPresent())
+ sb.append("-").append(optional.get());
+ } else {
+ if (optional.isPresent()) {
+ sb.append(pre.isPresent() ? "-" : "+-");
+ sb.append(optional.get());
+ }
+ }
+
+ return sb.toString();
+ }
+
+ /**
+ * Determines whether this {@code Version} is equal to another object.
+ *
+ * <p> Two {@code Version}s are equal if and only if they represent the
+ * same version string.
+ *
+ * <p> This method satisfies the general contract of the {@link
+ * Object#equals(Object) Object.equals} method. </p>
+ *
+ * @param ob
+ * The object to which this {@code Version} is to be compared
+ *
+ * @return {@code true} if, and only if, the given object is a {@code
+ * Version} that is identical to this {@code Version}
+ *
+ */
+ @Override
+ public boolean equals(Object ob) {
+ boolean ret = equalsIgnoreOpt(ob);
+ if (!ret)
+ return false;
+
+ Version that = (Version)ob;
+ return (this.optional().equals(that.optional()));
+ }
+
+ /**
+ * Determines whether this {@code Version} is equal to another
+ * disregarding optional build information.
+ *
+ * <p> Two {@code Version}s are equal if and only if they represent the
+ * same version string disregarding the optional build information.
+ *
+ * @param ob
+ * The object to which this {@code Version} is to be compared
+ *
+ * @return {@code true} if, and only if, the given object is a {@code
+ * Version} that is identical to this {@code Version}
+ * ignoring the optinal build information
+ *
+ */
+ public boolean equalsIgnoreOpt(Object ob) {
+ if (this == ob)
+ return true;
+ if (!(ob instanceof Version))
+ return false;
+
+ Version that = (Version)ob;
+ return (this.version().equals(that.version())
+ && this.pre().equals(that.pre())
+ && this.build().equals(that.build()));
+ }
+
+ /**
+ * Returns the hash code of this version.
+ *
+ * <p> This method satisfies the general contract of the {@link
+ * Object#hashCode Object.hashCode} method.
+ *
+ * @return The hashcode of this version
+ */
+ @Override
+ public int hashCode() {
+ int h = 1;
+ int p = 17;
+
+ h = p * h + version.hashCode();
+ h = p * h + pre.hashCode();
+ h = p * h + build.hashCode();
+ h = p * h + optional.hashCode();
+
+ return h;
+ }
+ }
+
}
< prev index next >