/*
* @(#)System.java 1.124 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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.
*
* This program 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 at /legal/license.txt).
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package java.lang;
import java.io.*;
import java.util.Properties;
import java.util.PropertyPermission;
import java.util.StringTokenizer;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.AllPermission;
import sun.net.InetAddressCachePolicy;
//import sun.reflect.Reflection;
import sun.security.util.SecurityConstants;
import com.sun.cdc.config.PackageManager;
import com.sun.cdc.config.DynamicProperties;
import com.sun.cdc.config.PropertyProvider;
/**
* The <code>System</code> class contains several useful class fields
* and methods. It cannot be instantiated.
* <p>
* Among the facilities provided by the <code>System</code> class
* are standard input, standard output, and error output streams;
* access to externally defined "properties"; a means of
* loading files and libraries; and a utility method for quickly
* copying a portion of an array.
*
* @author Arthur van Hoff
* @version 1.114 05/18/01
* @since JDK1.0
*/
public final class System {
/* First thing---register the natives */
/* No need to do this if ROMized
private static native void registerNatives();
static {
registerNatives();
}
*/
/** Don't let anyone instantiate this class */
private System() {
}
/**
* The "standard" input stream. This stream is already
* open and ready to supply input data. Typically this stream
* corresponds to keyboard input or another input source specified by
* the host environment or user.
*/
public final static InputStream in = nullInputStream();
/**
* The "standard" output stream. This stream is already
* open and ready to accept output data. Typically this stream
* corresponds to display output or another output destination
* specified by the host environment or user.
* <p>
* For simple stand-alone Java applications, a typical way to write
* a line of output data is:
* <blockquote><pre>
* System.out.println(data)
* </pre></blockquote>
* <p>
* See the <code>println</code> methods in class <code>PrintStream</code>.
*
* @see java.io.PrintStream#println()
* @see java.io.PrintStream#println(boolean)
* @see java.io.PrintStream#println(char)
* @see java.io.PrintStream#println(char[])
* @see java.io.PrintStream#println(double)
* @see java.io.PrintStream#println(float)
* @see java.io.PrintStream#println(int)
* @see java.io.PrintStream#println(long)
* @see java.io.PrintStream#println(java.lang.Object)
* @see java.io.PrintStream#println(java.lang.String)
*/
public final static PrintStream out = nullPrintStream();
/**
* The "standard" error output stream. This stream is already
* open and ready to accept output data.
* <p>
* Typically this stream corresponds to display output or another
* output destination specified by the host environment or user. By
* convention, this output stream is used to display error messages
* or other information that should come to the immediate attention
* of a user even if the principal output stream, the value of the
* variable <code>out</code>, has been redirected to a file or other
* destination that is typically not continuously monitored.
*/
public final static PrintStream err = nullPrintStream();
/* The security manager for the system.
*/
private static SecurityManager security = null;
/**
* Reassigns the "standard" input stream.
*
* <p>First, if there is a security manager, its <code>checkPermission</code>
* method is called with a <code>RuntimePermission("setIO")</code> permission
* to see if it's ok to reassign the "standard" input stream.
* <p>
*
* @param in the new standard input stream.
*
* @throws SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* reassigning of the standard input stream.
*
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*
* @since JDK1.1
*/
public static void setIn(InputStream in) {
checkIO();
setIn0(in);
}
/**
* Reassigns the "standard" output stream.
*
* <p>First, if there is a security manager, its <code>checkPermission</code>
* method is called with a <code>RuntimePermission("setIO")</code> permission
* to see if it's ok to reassign the "standard" output stream.
*
* @param out the new standard output stream
*
* @throws SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* reassigning of the standard output stream.
*
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*
* @since JDK1.1
*/
public static void setOut(PrintStream out) {
checkIO();
setOut0(out);
}
/**
* Reassigns the "standard" error output stream.
*
* <p>First, if there is a security manager, its <code>checkPermission</code>
* method is called with a <code>RuntimePermission("setIO")</code> permission
* to see if it's ok to reassign the "standard" error output stream.
*
* @param err the new standard error output stream.
*
* @throws SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* reassigning of the standard error output stream.
*
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*
* @since JDK1.1
*/
public static void setErr(PrintStream err) {
checkIO();
setErr0(err);
}
private static void checkIO() {
if (security != null)
security.checkPermission(new RuntimePermission("setIO"));
}
private static native void setIn0(InputStream in);
private static native void setOut0(PrintStream out);
private static native void setErr0(PrintStream err);
/**
* Sets the System security.
*
* <p> If there is a security manager already installed, this method first
* calls the security manager's <code>checkPermission</code> method
* with a <code>RuntimePermission("setSecurityManager")</code>
* permission to ensure it's ok to replace the existing
* security manager.
* This may result in throwing a <code>SecurityException</code>.
*
* <p> Otherwise, the argument is established as the current
* security manager. If the argument is <code>null</code> and no
* security manager has been established, then no action is taken and
* the method simply returns.
*
* @param s the security manager.
* @exception SecurityException if the security manager has already
* been set and its <code>checkPermission</code> method
* doesn't allow it to be replaced.
* @see #getSecurityManager
* @see SecurityManager#checkPermission
* @see java.lang.RuntimePermission
*/
public static
void setSecurityManager(final SecurityManager s) {
try {
s.checkPackageAccess("java.lang");
} catch (Exception e) {
// no-op
}
setSecurityManager0(s);
}
private static synchronized
void setSecurityManager0(final SecurityManager s) {
if (security != null) {
// ask the currently installed security manager if we
// can replace it.
security.checkPermission(new RuntimePermission
("setSecurityManager"));
}
if ((s != null) && (s.getClass().getClassLoader() != null)) {
// New security manager class is not on bootstrap classpath.
// Cause policy to get initialized before we install the new
// security manager, in order to prevent infinite loops when
// trying to initialize the policy (which usually involves
// accessing some security and/or system properties, which in turn
// calls the installed security manager's checkPermission method
// which will loop infinitely if there is a non-system class
// (in this case: the new security manager class) on the stack).
AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
s.getClass().getProtectionDomain().implies
(SecurityConstants.ALL_PERMISSION);
return null;
}
});
}
security = s;
InetAddressCachePolicy.setIfNotSet(InetAddressCachePolicy.FOREVER);
}
/**
* Gets the system security interface.
*
* @return if a security manager has already been established for the
* current application, then that security manager is returned;
* otherwise, <code>null</code> is returned.
* @see #setSecurityManager
*/
public static SecurityManager getSecurityManager() {
return security;
}
/**
* Returns the current time in milliseconds. Note that
* while the unit of time of the return value is a millisecond,
* the granularity of the value depends on the underlying
* operating system and may be larger. For example, many
* operating systems measure time in units of tens of
* milliseconds.
*
* <p> See the description of the class <code>Date</code> for
* a discussion of slight discrepancies that may arise between
* "computer time" and coordinated universal time (UTC).
*
* @return the difference, measured in milliseconds, between
* the current time and midnight, January 1, 1970 UTC.
* @see java.util.Date
*/
public static native long currentTimeMillis();
/**
* Copies an array from the specified source array, beginning at the
* specified position, to the specified position of the destination array.
* A subsequence of array components are copied from the source
* array referenced by <code>src</code> to the destination array
* referenced by <code>dest</code>. The number of components copied is
* equal to the <code>length</code> argument. The components at
* positions <code>srcPos</code> through
* <code>srcPos+length-1</code> in the source array are copied into
* positions <code>destPos</code> through
* <code>destPos+length-1</code>, respectively, of the destination
* array.
* <p>
* If the <code>src</code> and <code>dest</code> arguments refer to the
* same array object, then the copying is performed as if the
* components at positions <code>srcPos</code> through
* <code>srcPos+length-1</code> were first copied to a temporary
* array with <code>length</code> components and then the contents of
* the temporary array were copied into positions
* <code>destPos</code> through <code>destPos+length-1</code> of the
* destination array.
* <p>
* If <code>dest</code> is <code>null</code>, then a
* <code>NullPointerException</code> is thrown.
* <p>
* If <code>src</code> is <code>null</code>, then a
* <code>NullPointerException</code> is thrown and the destination
* array is not modified.
* <p>
* Otherwise, if any of the following is true, an
* <code>ArrayStoreException</code> is thrown and the destination is
* not modified:
* <ul>
* <li>The <code>src</code> argument refers to an object that is not an
* array.
* <li>The <code>dest</code> argument refers to an object that is not an
* array.
* <li>The <code>src</code> argument and <code>dest</code> argument refer
* to arrays whose component types are different primitive types.
* <li>The <code>src</code> argument refers to an array with a primitive
* component type and the <code>dest</code> argument refers to an array
* with a reference component type.
* <li>The <code>src</code> argument refers to an array with a reference
* component type and the <code>dest</code> argument refers to an array
* with a primitive component type.
* </ul>
* <p>
* Otherwise, if any of the following is true, an
* <code>IndexOutOfBoundsException</code> is
* thrown and the destination is not modified:
* <ul>
* <li>The <code>srcPos</code> argument is negative.
* <li>The <code>destPos</code> argument is negative.
* <li>The <code>length</code> argument is negative.
* <li><code>srcPos+length</code> is greater than
* <code>src.length</code>, the length of the source array.
* <li><code>destPos+length</code> is greater than
* <code>dest.length</code>, the length of the destination array.
* </ul>
* <p>
* Otherwise, if any actual component of the source array from
* position <code>srcPos</code> through
* <code>srcPos+length-1</code> cannot be converted to the component
* type of the destination array by assignment conversion, an
* <code>ArrayStoreException</code> is thrown. In this case, let
* <b><i>k</i></b> be the smallest nonnegative integer less than
* length such that <code>src[srcPos+</code><i>k</i><code>]</code>
* cannot be converted to the component type of the destination
* array; when the exception is thrown, source array components from
* positions <code>srcPos</code> through
* <code>srcPos+</code><i>k</i><code>-1</code>
* will already have been copied to destination array positions
* <code>destPos</code> through
* <code>destPos+</code><i>k</I><code>-1</code> and no other
* positions of the destination array will have been modified.
* (Because of the restrictions already itemized, this
* paragraph effectively applies only to the situation where both
* arrays have component types that are reference types.)
*
* @param src the source array.
* @param srcPos starting position in the source array.
* @param dest the destination array.
* @param destPos starting position in the destination data.
* @param length the number of array elements to be copied.
* @exception IndexOutOfBoundsException if copying would cause
* access of data outside array bounds.
* @exception ArrayStoreException if an element in the <code>src</code>
* array could not be stored into the <code>dest</code> array
* because of a type mismatch.
* @exception NullPointerException if either <code>src</code> or
* <code>dest</code> is <code>null</code>.
*/
public static native void arraycopy(Object src, int srcPos,
Object dest, int destPos,
int length);
/**
* Returns the same hash code for the given object as
* would be returned by the default method hashCode(),
* whether or not the given object's class overrides
* hashCode().
* The hash code for the null reference is zero.
*
* @param x object for which the hashCode is to be calculated
* @return the hashCode
* @since JDK1.1
*/
public static native int identityHashCode(Object x);
/**
* System properties. The following properties are guaranteed to be defined:
* <dl>
* <dt>java.version <dd>Java version number
* <dt>java.vendor <dd>Java vendor specific string
* <dt>java.vendor.url <dd>Java vendor URL
* <dt>java.home <dd>Java installation directory
* <dt>java.class.version <dd>Java class version number
* <dt>java.class.path <dd>Java classpath
* <dt>os.name <dd>Operating System Name
* <dt>os.arch <dd>Operating System Architecture
* <dt>os.version <dd>Operating System Version
* <dt>file.separator <dd>File separator ("/" on Unix)
* <dt>path.separator <dd>Path separator (":" on Unix)
* <dt>line.separator <dd>Line separator ("\n" on Unix)
* <dt>user.name <dd>User account name
* <dt>user.home <dd>User home directory
* <dt>user.dir <dd>User's current working directory
* </dl>
*/
private static Properties props;
private static native Properties initProperties(Properties props);
/**
* CLDC/MIDP properties.
* microedition.platform
* microedition.endocing
* microedition.configuration
* microedition.profiles
* microedition.locale
*/
private static Properties midpProps;
private static native Properties initCldcMidpProperties(Properties midpProps);
/**
* Determines the current system properties.
* <p>
* First, if there is a security manager, its
* <code>checkPropertiesAccess</code> method is called with no
* arguments. This may result in a security exception.
* <p>
* The current set of system properties for use by the
* {@link #getProperty(String)} method is returned as a
* <code>Properties</code> object. If there is no current set of
* system properties, a set of system properties is first created and
* initialized. This set of system properties always includes values
* for the following keys:
* <table summary="Shows property keys and associated values">
* <tr><th>Key</th>
* <th>Description of Associated Value</th></tr>
* <tr><td><code>java.version</code></td>
* <td>Java Runtime Environment version</td></tr>
* <tr><td><code>java.vendor</code></td>
* <td>Java Runtime Environment vendor</td></tr
* <tr><td><code>java.vendor.url</code></td>
* <td>Java vendor URL</td></tr>
* <tr><td><code>java.home</code></td>
* <td>Java installation directory</td></tr>
* <tr><td><code>java.vm.specification.version</code></td>
* <td>Java Virtual Machine specification version</td></tr>
* <tr><td><code>java.vm.specification.vendor</code></td>
* <td>Java Virtual Machine specification vendor</td></tr>
* <tr><td><code>java.vm.specification.name</code></td>
* <td>Java Virtual Machine specification name</td></tr>
* <tr><td><code>java.vm.version</code></td>
* <td>Java Virtual Machine implementation version</td></tr>
* <tr><td><code>java.vm.vendor</code></td>
* <td>Java Virtual Machine implementation vendor</td></tr>
* <tr><td><code>java.vm.name</code></td>
* <td>Java Virtual Machine implementation name</td></tr>
* <tr><td><code>java.specification.version</code></td>
* <td>Java Runtime Environment specification version</td></tr>
* <tr><td><code>java.specification.vendor</code></td>
* <td>Java Runtime Environment specification vendor</td></tr>
* <tr><td><code>java.specification.name</code></td>
* <td>Java Runtime Environment specification name</td></tr>
* <tr><td><code>java.class.version</code></td>
* <td>Java class format version number</td></tr>
* <tr><td><code>java.class.path</code></td>
* <td>Java class path</td></tr>
* <tr><td><code>java.library.path</code></td>
* <td>List of paths to search when loading libraries</td></tr>
* <tr><td><code>java.io.tmpdir</code></td>
* <td>Default temp file path</td></tr>
* <tr><td><code>java.compiler</code></td>
* <td>Name of JIT compiler to use</td></tr>
* <tr><td><code>java.ext.dirs</code></td>
* <td>Path of extension directory or directories</td></tr>
* <tr><td><code>os.name</code></td>
* <td>Operating system name</td></tr>
* <tr><td><code>os.arch</code></td>
* <td>Operating system architecture</td></tr>
* <tr><td><code>os.version</code></td>
* <td>Operating system version</td></tr>
* <tr><td><code>file.separator</code></td>
* <td>File separator ("/" on UNIX)</td></tr>
* <tr><td><code>path.separator</code></td>
* <td>Path separator (":" on UNIX)</td></tr>
* <tr><td><code>line.separator</code></td>
* <td>Line separator ("\n" on UNIX)</td></tr>
* <tr><td><code>user.name</code></td>
* <td>User's account name</td></tr>
* <tr><td><code>user.home</code></td>
* <td>User's home directory</td></tr>
* <tr><td><code>user.dir</code></td>
* <td>User's current working directory</td></tr>
* </table>
* <p>
* Multiple paths in a system property value are separated by the path
* separator character of the platform.
* <p>
* Note that even if the security manager does not permit the
* <code>getProperties</code> operation, it may choose to permit the
* {@link #getProperty(String)} operation.
*
* @return the system properties
* @exception SecurityException if a security manager exists and its
* <code>checkPropertiesAccess</code> method doesn't allow access
* to the system properties.
* @see #setProperties
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkPropertiesAccess()
* @see java.util.Properties
*/
public static Properties getProperties() {
if (security != null) {
security.checkPropertiesAccess();
}
/*
* If there are dynamic properties, resolve them all and
* add to the returned properties.
*/
DynamicProperties.addSnapshot(props);
return props;
}
/**
* Sets the system properties to the <code>Properties</code>
* argument.
* <p>
* First, if there is a security manager, its
* <code>checkPropertiesAccess</code> method is called with no
* arguments. This may result in a security exception.
* <p>
* The argument becomes the current set of system properties for use
* by the {@link #getProperty(String)} method. If the argument is
* <code>null</code>, then the current set of system properties is
* forgotten.
*
* @param props the new system properties.
* @exception SecurityException if a security manager exists and its
* <code>checkPropertiesAccess</code> method doesn't allow access
* to the system properties.
* @see #getProperties
* @see java.util.Properties
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkPropertiesAccess()
*/
public static void setProperties(Properties props) {
if (security != null) {
security.checkPropertiesAccess();
}
if (props == null) {
props = new Properties();
initProperties(props);
}
System.props = props;
}
/**
* Gets the system property indicated by the specified key.
* <p>
* First, if there is a security manager, its
* <code>checkPropertyAccess</code> method is called with the key as
* its argument. This may result in a SecurityException.
* <p>
* If there is no current set of system properties, a set of system
* properties is first created and initialized in the same manner as
* for the <code>getProperties</code> method.
*
* @param key the name of the system property.
* @return the string value of the system property,
* or <code>null</code> if there is no property with that key.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPropertyAccess</code> method doesn't allow
* access to the specified system property.
* @exception NullPointerException if <code>key</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #setProperty
* @see java.lang.SecurityException
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperties()
*/
public static String getProperty(String key) {
if (key == null) {
throw new NullPointerException("key can't be null");
}
if (key.equals("")) {
throw new IllegalArgumentException("key can't be empty");
}
if (security != null) {
security.checkPropertyAccess(key);
}
/* Check for the property provider first */
PropertyProvider provider = DynamicProperties.get(key);
if (provider != null) {
return provider.getValue(key, false);
}
/*
* MIDP Property Support
*
* Allow MIDP properties to override base properties in a MIDP
* context.
*/
if (sun.misc.CVM.isMIDPContext()) {
String prop = midpProps.getProperty(key);
if (prop != null) {
return prop;
}
}
return props.getProperty(key);
}
/**
* Gets the system property indicated by the specified key.
* <p>
* First, if there is a security manager, its
* <code>checkPropertyAccess</code> method is called with the
* <code>key</code> as its argument.
* <p>
* If there is no current set of system properties, a set of system
* properties is first created and initialized in the same manner as
* for the <code>getProperties</code> method.
*
* @param key the name of the system property.
* @param def a default value.
* @return the string value of the system property,
* or the default value if there is no property with that key.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPropertyAccess</code> method doesn't allow
* access to the specified system property.
* @exception NullPointerException if <code>key</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #setProperty
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
* @see java.lang.System#getProperties()
*/
public static String getProperty(String key, String def) {
if (key == null) {
throw new NullPointerException("key can't be null");
}
if (key.equals("")) {
throw new IllegalArgumentException("key can't be empty");
}
if (security != null) {
security.checkPropertyAccess(key);
}
/* Check for the property provider first */
PropertyProvider provider = DynamicProperties.get(key);
if (provider != null) {
String value = provider.getValue(key, false);
if (value == null) {
return def;
}
return value;
}
return props.getProperty(key, def);
}
/**
* Sets the system property indicated by the specified key.
* <p>
* First, if a security manager exists, its
* <code>SecurityManager.checkPermission</code> method
* is called with a <code>PropertyPermission(key, "write")</code>
* permission. This may result in a SecurityException being thrown.
* If no exception is thrown, the specified property is set to the given
* value.
* <p>
*
* @param key the name of the system property.
* @param value the value of the system property.
* @return the previous value of the system property,
* or <code>null</code> if it did not have one.
*
* @exception SecurityException if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* setting of the specified property.
* @exception NullPointerException if <code>key</code> is
* <code>null</code>.
* @exception IllegalArgumentException if <code>key</code> is empty.
* @see #getProperty
* @see java.lang.System#getProperty(java.lang.String)
* @see java.lang.System#getProperty(java.lang.String, java.lang.String)
* @see java.util.PropertyPermission
* @see SecurityManager#checkPermission
* @since 1.2
*/
public static String setProperty(String key, String value) {
if (key == null) {
throw new NullPointerException("key can't be null");
}
if (key.equals("")) {
throw new IllegalArgumentException("key can't be empty");
}
if (security != null)
security.checkPermission(new PropertyPermission(key,
SecurityConstants.PROPERTY_WRITE_ACTION));
/* Need to set the property in 'midpProps' to allow
* midlets to see properties set by the -D command line
* arugments.
*/
midpProps.setProperty(key, value);
return (String) props.setProperty(key, value);
}
/**
* Gets an environment variable. An environment variable is a
* system-dependent external variable that has a string value.
*
* deprecated The preferred way to extract system-dependent information
* is the system properties of the
* <code>java.lang.System.getProperty</code> methods and the
* corresponding <code>get</code><em>TypeName</em> methods of
* the <code>Boolean</code>, <code>Integer</code>, and
* <code>Long</code> primitive types. For example:
* <blockquote><pre>
* String classPath = System.getProperty("java.class.path",".");
* <br>
* if (Boolean.getBoolean("myapp.exper.mode"))
* enableExpertCommands();
* </pre></blockquote>
*
* param name of the environment variable
* return the value of the variable, or <code>null</code> if the variable
* is not defined.
* see java.lang.Boolean#getBoolean(java.lang.String)
* see java.lang.Integer#getInteger(java.lang.String)
* see java.lang.Integer#getInteger(java.lang.String, int)
* see java.lang.Integer#getInteger(java.lang.String, java.lang.Integer)
* see java.lang.Long#getLong(java.lang.String)
* see java.lang.Long#getLong(java.lang.String, long)
* see java.lang.Long#getLong(java.lang.String, java.lang.Long)
* see java.lang.System#getProperties()
* see java.lang.System#getProperty(java.lang.String)
* see java.lang.System#getProperty(java.lang.String, java.lang.String)
*
public static String getenv(String name) {
throw new Error("getenv no longer supported, use properties and -D instead: " + name);
}
*/
/**
* Terminates the currently running Java Virtual Machine. The
* argument serves as a status code; by convention, a nonzero status
* code indicates abnormal termination.
* <p>
* This method calls the <code>exit</code> method in class
* <code>Runtime</code>. This method never returns normally.
* <p>
* The call <code>System.exit(n)</code> is effectively equivalent to
* the call:
* <blockquote><pre>
* Runtime.getRuntime().exit(n)
* </pre></blockquote>
* <p>
* If process model exists, System.exit() must rely on the process
* exiting to release resources.
* <p>
* If process model does not exist, and a security manager exists,
* the security manager by default must prohibit calls to System.exit()
* by throwing SecurityException. Otherwise, the system will hang
* indefinitely when called,
* <p>
* @param status exit status.
* @throws SecurityException
* if a security manager exists and its <code>checkExit</code>
* method doesn't allow exit with the specified status.
* @see java.lang.Runtime#exit(int)
*/
public static void exit(int status) {
Runtime.getRuntime().exit(status);
}
/**
* Runs the garbage collector.
* <p>
* Calling the <code>gc</code> method suggests that the Java Virtual
* Machine expend effort toward recycling unused objects in order to
* make the memory they currently occupy available for quick reuse.
* When control returns from the method call, the Java Virtual
* Machine has made a best effort to reclaim space from all discarded
* objects.
* <p>
* The call <code>System.gc()</code> is effectively equivalent to the
* call:
* <blockquote><pre>
* Runtime.getRuntime().gc()
* </pre></blockquote>
*
* @see java.lang.Runtime#gc()
*/
public static void gc() {
if (sun.misc.CVM.callerIsMidlet()) {
sun.misc.CVM.gc();
} else {
Runtime.getRuntime().gc();
}
}
/**
* Runs the finalization methods of any objects pending finalization.
* <p>
* Calling this method suggests that the Java Virtual Machine expend
* effort toward running the <code>finalize</code> methods of objects
* that have been found to be discarded but whose <code>finalize</code>
* methods have not yet been run. When control returns from the
* method call, the Java Virtual Machine has made a best effort to
* complete all outstanding finalizations.
* <p>
* The call <code>System.runFinalization()</code> is effectively
* equivalent to the call:
* <blockquote><pre>
* Runtime.getRuntime().runFinalization()
* </pre></blockquote>
*
* @see java.lang.Runtime#runFinalization()
*/
public static void runFinalization() {
Runtime.getRuntime().runFinalization();
}
/**
* Enable or disable finalization on exit; doing so specifies that the
* finalizers of all objects that have finalizers that have not yet been
* automatically invoked are to be run before the Java runtime exits.
* By default, finalization on exit is disabled.
*
* <p>If there is a security manager,
* its <code>checkExit</code> method is first called
* with 0 as its argument to ensure the exit is allowed.
* This could result in a SecurityException.
*
* deprecated This method is inherently unsafe. It may result in
* finalizers being called on live objects while other threads are
* concurrently manipulating those objects, resulting in erratic
* behavior or deadlock.
* param value indicating enabling or disabling of finalization
* throws SecurityException
* if a security manager exists and its <code>checkExit</code>
* method doesn't allow the exit.
*
* see java.lang.Runtime#exit(int)
* see java.lang.Runtime#gc()
* see java.lang.SecurityManager#checkExit(int)
* since JDK1.1
*
public static void runFinalizersOnExit(boolean value) {
Runtime.getRuntime().runFinalizersOnExit(value);
}
*/
/**
* Loads a code file with the specified filename from the local file
* system as a dynamic library. The filename
* argument must be a complete path name.
* <p>
* The call <code>System.load(name)</code> is effectively equivalent
* to the call:
* <blockquote><pre>
* Runtime.getRuntime().load(name)
* </pre></blockquote>
*
* @param filename the file to load.
* @exception SecurityException if a security manager exists and its
* <code>checkLink</code> method doesn't allow
* loading of the specified dynamic library
* @exception UnsatisfiedLinkError if the file does not exist.
* @see java.lang.Runtime#load(java.lang.String)
* @see java.lang.SecurityManager#checkLink(java.lang.String)
*/
public static void load(String filename) {
Runtime.getRuntime().load0(getCallerClass(), filename);
}
/**
* Loads the system library specified by the <code>libname</code>
* argument. The manner in which a library name is mapped to the
* actual system library is system dependent.
* <p>
* The call <code>System.loadLibrary(name)</code> is effectively
* equivalent to the call
* <blockquote><pre>
* Runtime.getRuntime().loadLibrary(name)
* </pre></blockquote>
*
* @param libname the name of the library.
* @exception SecurityException if a security manager exists and its
* <code>checkLink</code> method doesn't allow
* loading of the specified dynamic library
* @exception UnsatisfiedLinkError if the library does not exist.
* @see java.lang.Runtime#loadLibrary(java.lang.String)
* @see java.lang.SecurityManager#checkLink(java.lang.String)
*/
public static void loadLibrary(String libname) {
Runtime.getRuntime().loadLibrary0(getCallerClass(), libname);
}
/**
* Maps a library name into a platform-specific string representing
* a native library.
*
* @param libname the name of the library.
* @return a platform-dependent native library name.
* @see java.lang.System#loadLibrary(java.lang.String)
* @see java.lang.ClassLoader#findLibrary(java.lang.String)
* @since 1.2
*/
public static native String mapLibraryName(String libname);
/**
* The following two methods exist because in, out, and err must be
* initialized to null. The compiler, however, cannot be permitted to
* inline access to them, since they are later set to more sensible values
* by initializeSystemClass().
*/
private static InputStream nullInputStream() throws NullPointerException {
if (currentTimeMillis() > 0)
return null;
throw new NullPointerException();
}
private static PrintStream nullPrintStream() throws NullPointerException {
if (currentTimeMillis() > 0)
return null;
throw new NullPointerException();
}
/**
* Initialize the system class. Called after thread initialization.
*/
private static void initializeSystemClass() throws ClassNotFoundException {
props = new Properties();
initProperties(props);
midpProps = new Properties();
initCldcMidpProperties(midpProps);
sun.misc.Version.init();
FileInputStream fdIn = new FileInputStream(FileDescriptor.in);
FileOutputStream fdOut = new FileOutputStream(FileDescriptor.out);
FileOutputStream fdErr = new FileOutputStream(FileDescriptor.err);
setIn0(new BufferedInputStream(fdIn));
setOut0(new PrintStream(new BufferedOutputStream(fdOut, 128), true));
setErr0(new PrintStream(new BufferedOutputStream(fdErr, 128), true));
// dynamic properties initialization (should be moved to more
// appropriate place when we have dynamic package loading implemented)
PackageManager.init();
// Load the zip library now in order to keep java.util.zip.ZipFile
// from trying to use itself to load this library later.
// CVM statically loads zip
//loadLibrary("zip");
// Currently File.deleteOnExit is built on JVM_Exit, which is a
// separate mechanism from shutdown hooks. Unfortunately in order to
// work properly JVM_Exit implicitly requires that Java signal
// handlers be set up for HUP, TERM, and INT (where available). If
// File.deleteOnExit were implemented in terms of shutdown hooks this
// call to Terminator.setup() could be removed.
Terminator.setup();
// Set the maximum amount of direct memory. This value is controlled
// by the vm option -XX:MaxDirectMemorySize=<size>. This method acts
// as an initializer only if it is called before sun.misc.VM.booted().
// Subsystems that are invoked during initialization can invoke
// sun.misc.VM.isBooted() in order to avoid doing things that should
// wait until the application class loader has been set up.
}
/* returns the class of the caller. */
//static Class getCallerClass() {
// NOTE use of more generic Reflection.getCallerClass()
// return Reflection.getCallerClass(3);
//}
static native Class getCallerClass();
}