blob: ba6e82af70320f8a865ad946120606c69720c253 [file] [log] [blame]
/*
* Copyright (c) 1995, 2021, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2019, Azul Systems, Inc. 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
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang;
import java.io.*;
import java.math.BigInteger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.List;
import java.util.Optional;
import java.util.StringTokenizer;
import jdk.internal.access.SharedSecrets;
import jdk.internal.loader.NativeLibrary;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
/**
* 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
* runtime can be obtained from the {@code getRuntime} method.
* <p>
* An application cannot create its own instance of this class.
*
* @see java.lang.Runtime#getRuntime()
* @since 1.0
*/
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.
*
* @return the {@code Runtime} object associated with the current
* Java application.
*/
public static Runtime getRuntime() {
return currentRuntime;
}
/** Don't let anyone else instantiate this class */
private Runtime() {}
/**
* Terminates the currently running Java virtual machine by initiating its
* shutdown sequence. This method never returns normally. The argument
* serves as a status code; by convention, a nonzero status code indicates
* abnormal termination.
*
* <p> All registered {@linkplain #addShutdownHook shutdown hooks}, if any,
* are started in some unspecified order and allowed to run concurrently
* until they finish. Once this is done the virtual machine
* {@linkplain #halt halts}.
*
* <p> If this method is invoked after all shutdown hooks have already
* been run and the status is nonzero then this method halts the
* virtual machine with the given status code. Otherwise, this method
* blocks indefinitely.
*
* <p> The {@link System#exit(int) System.exit} method is the
* conventional and convenient means of invoking this method.
*
* @param status
* Termination status. By convention, a nonzero status code
* indicates abnormal termination.
*
* @throws SecurityException
* If a security manager is present and its
* {@link SecurityManager#checkExit checkExit} method does not permit
* exiting with the specified status
*
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkExit(int)
* @see #addShutdownHook
* @see #removeShutdownHook
* @see #halt(int)
*/
public void exit(int status) {
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkExit(status);
}
Shutdown.exit(status);
}
/**
* Registers a new virtual-machine shutdown hook.
*
* <p> The Java virtual machine <i>shuts down</i> in response to two kinds
* of events:
*
* <ul>
*
* <li> The program <i>exits</i> normally, when the last non-daemon
* thread exits or when the {@link #exit exit} (equivalently,
* {@link System#exit(int) System.exit}) method is invoked, or
*
* <li> The virtual machine is <i>terminated</i> in response to a
* user interrupt, such as typing {@code ^C}, or a system-wide event,
* such as user logoff or system shutdown.
*
* </ul>
*
* <p> A <i>shutdown hook</i> is simply an initialized but unstarted
* thread. When the virtual machine begins its shutdown sequence it will
* start all registered shutdown hooks in some unspecified order and let
* them run concurrently. When all the hooks have finished it will then
* halt. Note that daemon threads will continue to run during the shutdown
* sequence, as will non-daemon threads if shutdown was initiated by
* invoking the {@link #exit exit} method.
*
* <p> Once the shutdown sequence has begun it can be stopped only by
* invoking the {@link #halt halt} method, which forcibly
* terminates the virtual machine.
*
* <p> Once the shutdown sequence has begun it is impossible to register a
* new shutdown hook or de-register a previously-registered hook.
* Attempting either of these operations will cause an
* {@link IllegalStateException} to be thrown.
*
* <p> Shutdown hooks run at a delicate time in the life cycle of a virtual
* machine and should therefore be coded defensively. They should, in
* particular, be written to be thread-safe and to avoid deadlocks insofar
* as possible. They should also not rely blindly upon services that may
* have registered their own shutdown hooks and therefore may themselves in
* the process of shutting down. Attempts to use other thread-based
* services such as the AWT event-dispatch thread, for example, may lead to
* deadlocks.
*
* <p> Shutdown hooks should also finish their work quickly. When a
* program invokes {@link #exit exit} the expectation is
* that the virtual machine will promptly shut down and exit. When the
* virtual machine is terminated due to user logoff or system shutdown the
* underlying operating system may only allow a fixed amount of time in
* which to shut down and exit. It is therefore inadvisable to attempt any
* user interaction or to perform a long-running computation in a shutdown
* hook.
*
* <p> Uncaught exceptions are handled in shutdown hooks just as in any
* other thread, by invoking the
* {@link ThreadGroup#uncaughtException uncaughtException} method of the
* thread's {@link ThreadGroup} object. The default implementation of this
* method prints the exception's stack trace to {@link System#err} and
* terminates the thread; it does not cause the virtual machine to exit or
* halt.
*
* <p> In rare circumstances the virtual machine may <i>abort</i>, that is,
* stop running without shutting down cleanly. This occurs when the
* virtual machine is terminated externally, for example with the
* {@code SIGKILL} signal on Unix or the {@code TerminateProcess} call on
* Microsoft Windows. The virtual machine may also abort if a native
* method goes awry by, for example, corrupting internal data structures or
* attempting to access nonexistent memory. If the virtual machine aborts
* then no guarantee can be made about whether or not any shutdown hooks
* will be run.
*
* @param hook
* An initialized but unstarted {@link Thread} object
*
* @throws IllegalArgumentException
* If the specified hook has already been registered,
* or if it can be determined that the hook is already running or
* has already been run
*
* @throws IllegalStateException
* If the virtual machine is already in the process
* of shutting down
*
* @throws SecurityException
* If a security manager is present and it denies
* {@link RuntimePermission}("shutdownHooks")
*
* @see #removeShutdownHook
* @see #halt(int)
* @see #exit(int)
* @since 1.3
*/
public void addShutdownHook(Thread hook) {
@SuppressWarnings("removal")
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("shutdownHooks"));
}
ApplicationShutdownHooks.add(hook);
}
/**
* De-registers a previously-registered virtual-machine shutdown hook.
*
* @param hook the hook to remove
* @return {@code true} if the specified hook had previously been
* registered and was successfully de-registered, {@code false}
* otherwise.
*
* @throws IllegalStateException
* If the virtual machine is already in the process of shutting
* down
*
* @throws SecurityException
* If a security manager is present and it denies
* {@link RuntimePermission}("shutdownHooks")
*
* @see #addShutdownHook
* @see #exit(int)
* @since 1.3
*/
public boolean removeShutdownHook(Thread hook) {
@SuppressWarnings("removal")
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("shutdownHooks"));
}
return ApplicationShutdownHooks.remove(hook);
}
/**
* Forcibly terminates the currently running Java virtual machine. This
* method never returns normally.
*
* <p> This method should be used with extreme caution. Unlike the
* {@link #exit exit} method, this method does not cause shutdown
* hooks to be started. If the shutdown sequence has already been
* initiated then this method does not wait for any running
* shutdown hooks to finish their work.
*
* @param status
* Termination status. By convention, a nonzero status code
* indicates abnormal termination. If the {@link Runtime#exit exit}
* (equivalently, {@link System#exit(int) System.exit}) method
* has already been invoked then this status code
* will override the status code passed to that method.
*
* @throws SecurityException
* If a security manager is present and its
* {@link SecurityManager#checkExit checkExit} method
* does not permit an exit with the specified status
*
* @see #exit
* @see #addShutdownHook
* @see #removeShutdownHook
* @since 1.3
*/
public void halt(int status) {
@SuppressWarnings("removal")
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkExit(status);
}
Shutdown.beforeHalt();
Shutdown.halt(status);
}
/**
* Executes the specified string command in a separate process.
*
* <p>This is a convenience method. An invocation of the form
* {@code exec(command)}
* behaves in exactly the same way as the invocation
* {@link #exec(String, String[], File) exec}{@code (command, null, null)}.
*
* @param command a specified system command.
*
* @return A new {@link Process} object for managing the subprocess
*
* @throws SecurityException
* If a security manager exists and its
* {@link SecurityManager#checkExec checkExec}
* method doesn't allow creation of the subprocess
*
* @throws IOException
* If an I/O error occurs
*
* @throws NullPointerException
* If {@code command} is {@code null}
*
* @throws IllegalArgumentException
* If {@code command} is empty
*
* @see #exec(String[], String[], File)
* @see ProcessBuilder
*/
public Process exec(String command) throws IOException {
return exec(command, null, null);
}
/**
* Executes the specified string command in a separate process with the
* specified environment.
*
* <p>This is a convenience method. An invocation of the form
* {@code exec(command, envp)}
* behaves in exactly the same way as the invocation
* {@link #exec(String, String[], File) exec}{@code (command, envp, null)}.
*
* @param command a specified system command.
*
* @param envp array of strings, each element of which
* has environment variable settings in the format
* <i>name</i>=<i>value</i>, or
* {@code null} if the subprocess should inherit
* the environment of the current process.
*
* @return A new {@link Process} object for managing the subprocess
*
* @throws SecurityException
* If a security manager exists and its
* {@link SecurityManager#checkExec checkExec}
* method doesn't allow creation of the subprocess
*
* @throws IOException
* If an I/O error occurs
*
* @throws NullPointerException
* If {@code command} is {@code null},
* or one of the elements of {@code envp} is {@code null}
*
* @throws IllegalArgumentException
* If {@code command} is empty
*
* @see #exec(String[], String[], File)
* @see ProcessBuilder
*/
public Process exec(String command, String[] envp) throws IOException {
return exec(command, envp, null);
}
/**
* Executes the specified string command in a separate process with the
* specified environment and working directory.
*
* <p>This is a convenience method. An invocation of the form
* {@code exec(command, envp, dir)}
* behaves in exactly the same way as the invocation
* {@link #exec(String[], String[], File) exec}{@code (cmdarray, envp, dir)},
* where {@code cmdarray} is an array of all the tokens in
* {@code command}.
*
* <p>More precisely, the {@code command} string is broken
* into tokens using a {@link StringTokenizer} created by the call
* {@code new {@link StringTokenizer}(command)} with no
* further modification of the character categories. The tokens
* produced by the tokenizer are then placed in the new string
* array {@code cmdarray}, in the same order.
*
* @param command a specified system command.
*
* @param envp array of strings, each element of which
* has environment variable settings in the format
* <i>name</i>=<i>value</i>, or
* {@code null} if the subprocess should inherit
* the environment of the current process.
*
* @param dir the working directory of the subprocess, or
* {@code null} if the subprocess should inherit
* the working directory of the current process.
*
* @return A new {@link Process} object for managing the subprocess
*
* @throws SecurityException
* If a security manager exists and its
* {@link SecurityManager#checkExec checkExec}
* method doesn't allow creation of the subprocess
*
* @throws IOException
* If an I/O error occurs
*
* @throws NullPointerException
* If {@code command} is {@code null},
* or one of the elements of {@code envp} is {@code null}
*
* @throws IllegalArgumentException
* If {@code command} is empty
*
* @see ProcessBuilder
* @since 1.3
*/
public Process exec(String command, String[] envp, File dir)
throws IOException {
if (command.isEmpty())
throw new IllegalArgumentException("Empty command");
StringTokenizer st = new StringTokenizer(command);
String[] cmdarray = new String[st.countTokens()];
for (int i = 0; st.hasMoreTokens(); i++)
cmdarray[i] = st.nextToken();
return exec(cmdarray, envp, dir);
}
/**
* Executes the specified command and arguments in a separate process.
*
* <p>This is a convenience method. An invocation of the form
* {@code exec(cmdarray)}
* behaves in exactly the same way as the invocation
* {@link #exec(String[], String[], File) exec}{@code (cmdarray, null, null)}.
*
* @param cmdarray array containing the command to call and
* its arguments.
*
* @return A new {@link Process} object for managing the subprocess
*
* @throws SecurityException
* If a security manager exists and its
* {@link SecurityManager#checkExec checkExec}
* method doesn't allow creation of the subprocess
*
* @throws IOException
* If an I/O error occurs
*
* @throws NullPointerException
* If {@code cmdarray} is {@code null},
* or one of the elements of {@code cmdarray} is {@code null}
*
* @throws IndexOutOfBoundsException
* If {@code cmdarray} is an empty array
* (has length {@code 0})
*
* @see ProcessBuilder
*/
public Process exec(String cmdarray[]) throws IOException {
return exec(cmdarray, null, null);
}
/**
* Executes the specified command and arguments in a separate process
* with the specified environment.
*
* <p>This is a convenience method. An invocation of the form
* {@code exec(cmdarray, envp)}
* behaves in exactly the same way as the invocation
* {@link #exec(String[], String[], File) exec}{@code (cmdarray, envp, null)}.
*
* @param cmdarray array containing the command to call and
* its arguments.
*
* @param envp array of strings, each element of which
* has environment variable settings in the format
* <i>name</i>=<i>value</i>, or
* {@code null} if the subprocess should inherit
* the environment of the current process.
*
* @return A new {@link Process} object for managing the subprocess
*
* @throws SecurityException
* If a security manager exists and its
* {@link SecurityManager#checkExec checkExec}
* method doesn't allow creation of the subprocess
*
* @throws IOException
* If an I/O error occurs
*
* @throws NullPointerException
* If {@code cmdarray} is {@code null},
* or one of the elements of {@code cmdarray} is {@code null},
* or one of the elements of {@code envp} is {@code null}
*
* @throws IndexOutOfBoundsException
* If {@code cmdarray} is an empty array
* (has length {@code 0})
*
* @see ProcessBuilder
*/
public Process exec(String[] cmdarray, String[] envp) throws IOException {
return exec(cmdarray, envp, null);
}
/**
* Executes the specified command and arguments in a separate process with
* the specified environment and working directory.
*
* <p>Given an array of strings {@code cmdarray}, representing the
* tokens of a command line, and an array of strings {@code envp},
* representing "environment" variable settings, this method creates
* a new process in which to execute the specified command.
*
* <p>This method checks that {@code cmdarray} is a valid operating
* system command. Which commands are valid is system-dependent,
* but at the very least the command must be a non-empty list of
* non-null strings.
*
* <p>If {@code envp} is {@code null}, the subprocess inherits the
* environment settings of the current process.
*
* <p>A minimal set of system dependent environment variables may
* be required to start a process on some operating systems.
* As a result, the subprocess may inherit additional environment variable
* settings beyond those in the specified environment.
*
* <p>{@link ProcessBuilder#start()} is now the preferred way to
* start a process with a modified environment.
*
* <p>The working directory of the new subprocess is specified by {@code dir}.
* If {@code dir} is {@code null}, the subprocess inherits the
* current working directory of the current process.
*
* <p>If a security manager exists, its
* {@link SecurityManager#checkExec checkExec}
* method is invoked with the first component of the array
* {@code cmdarray} as its argument. This may result in a
* {@link SecurityException} being thrown.
*
* <p>Starting an operating system process is highly system-dependent.
* Among the many things that can go wrong are:
* <ul>
* <li>The operating system program file was not found.
* <li>Access to the program file was denied.
* <li>The working directory does not exist.
* </ul>
*
* <p>In such cases an exception will be thrown. The exact nature
* of the exception is system-dependent, but it will always be a
* subclass of {@link IOException}.
*
* <p>If the operating system does not support the creation of
* processes, an {@link UnsupportedOperationException} will be thrown.
*
*
* @param cmdarray array containing the command to call and
* its arguments.
*
* @param envp array of strings, each element of which
* has environment variable settings in the format
* <i>name</i>=<i>value</i>, or
* {@code null} if the subprocess should inherit
* the environment of the current process.
*
* @param dir the working directory of the subprocess, or
* {@code null} if the subprocess should inherit
* the working directory of the current process.
*
* @return A new {@link Process} object for managing the subprocess
*
* @throws SecurityException
* If a security manager exists and its
* {@link SecurityManager#checkExec checkExec}
* method doesn't allow creation of the subprocess
*
* @throws UnsupportedOperationException
* If the operating system does not support the creation of processes.
*
* @throws IOException
* If an I/O error occurs
*
* @throws NullPointerException
* If {@code cmdarray} is {@code null},
* or one of the elements of {@code cmdarray} is {@code null},
* or one of the elements of {@code envp} is {@code null}
*
* @throws IndexOutOfBoundsException
* If {@code cmdarray} is an empty array
* (has length {@code 0})
*
* @see ProcessBuilder
* @since 1.3
*/
public Process exec(String[] cmdarray, String[] envp, File dir)
throws IOException {
return new ProcessBuilder(cmdarray)
.environment(envp)
.directory(dir)
.start();
}
/**
* Returns the number of processors available to the Java virtual machine.
*
* <p> This value may change during a particular invocation of the virtual
* machine. Applications that are sensitive to the number of available
* processors should therefore occasionally poll this property and adjust
* their resource usage appropriately. </p>
*
* @return the maximum number of processors available to the virtual
* machine; never smaller than one
* @since 1.4
*/
public native int availableProcessors();
/**
* Returns the amount of free memory in the Java Virtual Machine.
* Calling the
* {@code gc} method may result in increasing the value returned
* by {@code freeMemory.}
*
* @return an approximation to the total amount of memory currently
* available for future allocated objects, measured in bytes.
*/
public native long freeMemory();
/**
* Returns the total amount of memory in the Java virtual machine.
* The value returned by this method may vary over time, depending on
* the host environment.
* <p>
* Note that the amount of memory required to hold an object of any
* given type may be implementation-dependent.
*
* @return the total amount of memory currently available for current
* and future objects, measured in bytes.
*/
public native long totalMemory();
/**
* Returns the maximum amount of memory that the Java virtual machine
* will attempt to use. If there is no inherent limit then the value
* {@link java.lang.Long#MAX_VALUE} will be returned.
*
* @return the maximum amount of memory that the virtual machine will
* attempt to use, measured in bytes
* @since 1.4
*/
public native long maxMemory();
/**
* Runs the garbage collector in the Java Virtual Machine.
* <p>
* Calling this method suggests that the Java Virtual Machine
* expend effort toward recycling unused objects in order to
* make the memory they currently occupy available for reuse
* by the Java Virtual Machine.
* When control returns from the method call, the Java Virtual Machine
* has made a best effort to reclaim space from all unused objects.
* There is no guarantee that this effort will recycle any particular
* number of unused objects, reclaim any particular amount of space, or
* complete at any particular time, if at all, before the method returns or ever.
* <p>
* The name {@code gc} stands for "garbage
* collector". The Java Virtual Machine performs this recycling
* process automatically as needed, in a separate thread, even if the
* {@code gc} method is not invoked explicitly.
* <p>
* The method {@link System#gc()} is the conventional and convenient
* means of invoking this method.
*/
public native void gc();
/**
* Runs the finalization methods of any objects pending finalization.
* Calling this method suggests that the Java virtual machine expend
* effort toward running the {@code finalize} methods of objects
* that have been found to be discarded but whose {@code finalize}
* methods have not yet been run. When control returns from the
* method call, the virtual machine has made a best effort to
* complete all outstanding finalizations.
* <p>
* The virtual machine performs the finalization process
* automatically as needed, in a separate thread, if the
* {@code runFinalization} method is not invoked explicitly.
* <p>
* The method {@link System#runFinalization()} is the conventional
* and convenient means of invoking this method.
*
* @see java.lang.Object#finalize()
*/
public void runFinalization() {
SharedSecrets.getJavaLangRefAccess().runFinalization();
}
/**
* Loads the native library specified by the filename argument. The filename
* argument must be an absolute path name.
* (for example
* {@code Runtime.getRuntime().load("/home/avh/lib/libX11.so");}).
*
* If the filename argument, when stripped of any platform-specific library
* prefix, path, and file extension, indicates a library whose name is,
* for example, L, and a native library called L is statically linked
* with the VM, then the JNI_OnLoad_L function exported by the library
* is invoked rather than attempting to load a dynamic library.
* A filename matching the argument does not have to exist in the file
* system.
* See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
* for more details.
*
* Otherwise, the filename argument is mapped to a native library image in
* an implementation-dependent manner.
* <p>
* First, if there is a security manager, its {@code checkLink}
* method is called with the {@code filename} as its argument.
* This may result in a security exception.
* <p>
* This is similar to the method {@link #loadLibrary(String)}, but it
* accepts a general file name as an argument rather than just a library
* name, allowing any file of native code to be loaded.
* <p>
* The method {@link System#load(String)} is the conventional and
* convenient means of invoking this method.
*
* @param filename the file to load.
* @throws SecurityException if a security manager exists and its
* {@code checkLink} method doesn't allow
* loading of the specified dynamic library
* @throws UnsatisfiedLinkError if either the filename is not an
* absolute path name, the native library is not statically
* linked with the VM, or the library cannot be mapped to
* a native library image by the host system.
* @throws NullPointerException if {@code filename} is
* {@code null}
* @see java.lang.Runtime#getRuntime()
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkLink(java.lang.String)
*/
@CallerSensitive
public void load(String filename) {
load0(Reflection.getCallerClass(), filename);
}
void load0(Class<?> fromClass, String filename) {
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkLink(filename);
}
File file = new File(filename);
if (!file.isAbsolute()) {
throw new UnsatisfiedLinkError(
"Expecting an absolute path of the library: " + filename);
}
ClassLoader.loadLibrary(fromClass, file);
}
/**
* Loads the native library specified by the {@code libname}
* argument. The {@code libname} argument must not contain any platform
* specific prefix, file extension or path. If a native library
* called {@code libname} is statically linked with the VM, then the
* JNI_OnLoad_{@code libname} function exported by the library is invoked.
* See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
* for more details.
*
* Otherwise, the libname argument is loaded from a system library
* location and mapped to a native library image in an
* implementation-dependent manner.
* <p>
* First, if there is a security manager, its {@code checkLink}
* method is called with the {@code libname} as its argument.
* This may result in a security exception.
* <p>
* The method {@link System#loadLibrary(String)} is the conventional
* and convenient means of invoking this method. If native
* methods are to be used in the implementation of a class, a standard
* strategy is to put the native code in a library file (call it
* {@code LibFile}) and then to put a static initializer:
* <blockquote><pre>
* static { System.loadLibrary("LibFile"); }
* </pre></blockquote>
* within the class declaration. When the class is loaded and
* initialized, the necessary native code implementation for the native
* methods will then be loaded as well.
* <p>
* If this method is called more than once with the same library
* name, the second and subsequent calls are ignored.
*
* @param libname the name of the library.
* @throws SecurityException if a security manager exists and its
* {@code checkLink} method doesn't allow
* loading of the specified dynamic library
* @throws UnsatisfiedLinkError if either the libname argument
* contains a file path, the native library is not statically
* linked with the VM, or the library cannot be mapped to a
* native library image by the host system.
* @throws NullPointerException if {@code libname} is
* {@code null}
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkLink(java.lang.String)
*/
@CallerSensitive
public void loadLibrary(String libname) {
loadLibrary0(Reflection.getCallerClass(), libname);
}
void loadLibrary0(Class<?> fromClass, String libname) {
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkLink(libname);
}
if (libname.indexOf((int)File.separatorChar) != -1) {
throw new UnsatisfiedLinkError(
"Directory separator should not appear in library name: " + libname);
}
ClassLoader.loadLibrary(fromClass, libname);
}
/**
* Returns the version of the Java Runtime Environment as a {@link Version}.
*
* @return the {@link Version} of the Java Runtime Environment
*
* @since 9
*/
public static Version version() {
var v = version;
if (v == null) {
v = new Version(VersionProps.versionNumbers(),
VersionProps.pre(), VersionProps.build(),
VersionProps.optional());
version = v;
}
return v;
}
/**
* A representation of a version string for an implementation of the
* Java&nbsp;SE Platform. A version string consists of a version number
* optionally followed by pre-release and build information.
*
* <h2><a id="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 an unsigned integer numeral without leading zeros. The final
* element in a version number must not be zero. When an element is
* incremented, all subsequent elements are removed. 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 four elements
* are assigned specific meanings, as follows:</p>
*
* <blockquote><pre>
* $FEATURE.$INTERIM.$UPDATE.$PATCH
* </pre></blockquote>
*
* <ul>
*
* <li><p> <a id="FEATURE">{@code $FEATURE}</a> &#x2014; The
* feature-release counter, incremented for every feature release
* regardless of release content. Features may be added in a feature
* release; they may also be removed, if advance notice was given at least
* one feature release ahead of time. Incompatible changes may be made
* when justified. </p></li>
*
* <li><p> <a id="INTERIM">{@code $INTERIM}</a> &#x2014; The
* interim-release counter, incremented for non-feature releases that
* contain compatible bug fixes and enhancements but no incompatible
* changes, no feature removals, and no changes to standard APIs.
* </p></li>
*
* <li><p> <a id="UPDATE">{@code $UPDATE}</a> &#x2014; The update-release
* counter, incremented for compatible update releases that fix security
* issues, regressions, and bugs in newer features. </p></li>
*
* <li><p> <a id="PATCH">{@code $PATCH}</a> &#x2014; The emergency
* patch-release counter, incremented only when it's necessary to produce
* an emergency release to fix a critical issue. </p></li>
*
* </ul>
*
* <p> The fifth and later elements of a version number are free for use by
* platform implementors, to identify implementor-specific patch
* releases. </p>
*
* <p> A version number never has trailing zero elements. If an element
* and all those that follow it logically have the value zero then all of
* them are omitted. </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
* 10.0.4} is less than {@code 10.1.2}. 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 10.0.2} is less than {@code 10.0.2.1}. </p>
*
* <h2><a id="verStr">Version strings</a></h2>
*
* <p> A <em>version string</em>, {@code $VSTR}, is a version number {@code
* $VNUM}, as described above, optionally followed by pre-release and build
* information, in one of the following formats: </p>
*
* <blockquote><pre>
* $VNUM(-$PRE)?\+$BUILD(-$OPT)?
* $VNUM-$PRE(-$OPT)?
* $VNUM(\+-$OPT)?
* </pre></blockquote>
*
* <p> where: </p>
*
* <ul>
*
* <li><p> <a id="pre">{@code $PRE}</a>, matching {@code ([a-zA-Z0-9]+)}
* &#x2014; 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. </p></li>
*
* <li><p> <a id="build">{@code $BUILD}</a>, matching {@code
* (0|[1-9][0-9]*)} &#x2014; 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>
*
* <li><p> <a id="opt">{@code $OPT}</a>, matching {@code ([-a-zA-Z0-9.]+)}
* &#x2014; 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></li>
*
* </ul>
*
* <p> A version string {@code 10-ea} matches {@code $VNUM = "10"} and
* {@code $PRE = "ea"}. The version string {@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 #compareToIgnoreOptional(Version)
* compareToIgnoreOptional()} should be used consistently with the
* corresponding methods {@link #equals(Object) equals()} and {@link
* #equalsIgnoreOptional(Object) equalsIgnoreOptional()}. </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:</p>
*
* <blockquote><pre>
* $VNUM(-$PRE)?
* </pre></blockquote>
*
* <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
* class; programmers should treat instances that are
* {@linkplain #equals(Object) equal} as interchangeable and should not
* use instances for synchronization, or unpredictable behavior may
* occur. For example, in a future release, synchronization may fail.</p>
*
* @since 9
*/
@jdk.internal.ValueBased
public static final 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;
/*
* List of version number components passed to this constructor MUST
* be at least unmodifiable (ideally immutable). In the case of an
* unmodifiable list, the caller MUST hand the list over to this
* constructor and never change the underlying list.
*/
private Version(List<Integer> unmodifiableListOfVersions,
Optional<String> pre,
Optional<Integer> build,
Optional<String> optional)
{
this.version = unmodifiableListOfVersions;
this.pre = pre;
this.build = build;
this.optional = optional;
}
/**
* 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 The Version of the given string
*/
public static Version parse(String s) {
if (s == null)
throw new NullPointerException();
// Shortcut to avoid initializing VersionPattern when creating
// feature-version constants during startup
if (isSimpleNumber(s)) {
return new Version(List.of(Integer.parseInt(s)),
Optional.empty(), Optional.empty(), Optional.empty());
}
Matcher m = VersionPattern.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
String[] split = m.group(VersionPattern.VNUM_GROUP).split("\\.");
Integer[] version = new Integer[split.length];
for (int i = 0; i < split.length; i++) {
version[i] = Integer.parseInt(split[i]);
}
Optional<String> pre = Optional.ofNullable(
m.group(VersionPattern.PRE_GROUP));
String b = m.group(VersionPattern.BUILD_GROUP);
// $BUILD is an integer
Optional<Integer> build = (b == null)
? Optional.empty()
: Optional.of(Integer.parseInt(b));
Optional<String> optional = Optional.ofNullable(
m.group(VersionPattern.OPT_GROUP));
// empty '+'
if (!build.isPresent()) {
if (m.group(VersionPattern.PLUS_GROUP) != null) {
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 + "'");
}
} else {
if (optional.isPresent() && !pre.isPresent()) {
throw new IllegalArgumentException("optional component"
+ " must be preceded by a pre-release component"
+ " or '+': '" + s + "'");
}
}
}
return new Version(List.of(version), pre, build, optional);
}
private static boolean isSimpleNumber(String s) {
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
char lowerBound = (i > 0) ? '0' : '1';
if (c < lowerBound || c > '9') {
return false;
}
}
return true;
}
/**
* Returns the value of the <a href="#FEATURE">feature</a> element of
* the version number.
*
* @return The value of the feature element
*
* @since 10
*/
public int feature() {
return version.get(0);
}
/**
* Returns the value of the <a href="#INTERIM">interim</a> element of
* the version number, or zero if it is absent.
*
* @return The value of the interim element, or zero
*
* @since 10
*/
public int interim() {
return (version.size() > 1 ? version.get(1) : 0);
}
/**
* Returns the value of the <a href="#UPDATE">update</a> element of the
* version number, or zero if it is absent.
*
* @return The value of the update element, or zero
*
* @since 10
*/
public int update() {
return (version.size() > 2 ? version.get(2) : 0);
}
/**
* Returns the value of the <a href="#PATCH">patch</a> element of the
* version number, or zero if it is absent.
*
* @return The value of the patch element, or zero
*
* @since 10
*/
public int patch() {
return (version.size() > 3 ? version.get(3) : 0);
}
/**
* Returns the value of the major element of the version number.
*
* @deprecated As of Java&nbsp;SE 10, the first element of a version
* number is not the major-release number but the feature-release
* counter, incremented for every time-based release. Use the {@link
* #feature()} method in preference to this method. For compatibility,
* this method returns the value of the <a href="#FEATURE">feature</a>
* element.
*
* @return The value of the feature element
*/
@Deprecated(since = "10")
public int major() {
return feature();
}
/**
* Returns the value of the minor element of the version number, or
* zero if it is absent.
*
* @deprecated As of Java&nbsp;SE 10, the second element of a version
* number is not the minor-release number but the interim-release
* counter, incremented for every interim release. Use the {@link
* #interim()} method in preference to this method. For compatibility,
* this method returns the value of the <a href="#INTERIM">interim</a>
* element, or zero if it is absent.
*
* @return The value of the interim element, or zero
*/
@Deprecated(since = "10")
public int minor() {
return interim();
}
/**
* Returns the value of the security element of the version number, or
* zero if it is absent.
*
* @deprecated As of Java&nbsp;SE 10, the third element of a version
* number is not the security level but the update-release counter,
* incremented for every update release. Use the {@link #update()}
* method in preference to this method. For compatibility, this method
* returns the value of the <a href="#UPDATE">update</a> element, or
* zero if it is absent.
*
* @return The value of the update element, or zero
*/
@Deprecated(since = "10")
public int security() {
return update();
}
/**
* Returns an unmodifiable {@link java.util.List List} of the integers
* represented in the <a href="#verNum">version number</a>.
* The {@code List} always contains at least one element corresponding to
* the <a href="#FEATURE">feature version number</a>.
*
* @return An unmodifiable list of the integers
* represented 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 following 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>
*
* @param obj
* 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 obj) {
return compare(obj, 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> This method provides ordering which is consistent with
* {@code equalsIgnoreOptional()}. </p>
*
* @param obj
* 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 compareToIgnoreOptional(Version obj) {
return compare(obj, true);
}
private int compare(Version obj, boolean ignoreOpt) {
if (obj == null)
throw new NullPointerException();
int ret = compareVersion(obj);
if (ret != 0)
return ret;
ret = comparePre(obj);
if (ret != 0)
return ret;
ret = compareBuild(obj);
if (ret != 0)
return ret;
if (!ignoreOpt)
return compareOptional(obj);
return 0;
}
private int compareVersion(Version obj) {
int size = version.size();
int oSize = obj.version().size();
int min = Math.min(size, oSize);
for (int i = 0; i < min; i++) {
int val = version.get(i);
int oVal = obj.version().get(i);
if (val != oVal)
return val - oVal;
}
return size - oSize;
}
private int comparePre(Version obj) {
Optional<String> oPre = obj.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 obj) {
Optional<Integer> oBuild = obj.build();
if (oBuild.isPresent()) {
return (build.isPresent()
? build.get().compareTo(oBuild.get())
: -1);
} else if (build.isPresent()) {
return 1;
}
return 0;
}
private int compareOptional(Version obj) {
Optional<String> oOpt = obj.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.
*
* @param obj
* 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 obj) {
boolean ret = equalsIgnoreOptional(obj);
if (!ret)
return false;
Version that = (Version)obj;
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 obj
* 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 optional build information
*
*/
public boolean equalsIgnoreOptional(Object obj) {
if (this == obj)
return true;
return (obj instanceof Version that)
&& (this.version().equals(that.version())
&& this.pre().equals(that.pre())
&& this.build().equals(that.build()));
}
/**
* Returns the hash code of this version.
*
* @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;
}
}
private static class VersionPattern {
// $VNUM(-$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 PRE = "(?:-(?<PRE>[a-zA-Z0-9]+))?";
private static final String BUILD
= "(?:(?<PLUS>\\+)(?<BUILD>0|[1-9][0-9]*)?)?";
private static final String OPT = "(?:-(?<OPT>[-a-zA-Z0-9.]+))?";
private static final String VSTR_FORMAT = VNUM + PRE + BUILD + OPT;
static final Pattern VSTR_PATTERN = Pattern.compile(VSTR_FORMAT);
static final String VNUM_GROUP = "VNUM";
static final String PRE_GROUP = "PRE";
static final String PLUS_GROUP = "PLUS";
static final String BUILD_GROUP = "BUILD";
static final String OPT_GROUP = "OPT";
}
}