system.java

一个开源的JAVA虚拟机

/*
    libaegisvm - The Aegis Virtual Machine for executing Java bytecode
    Copyright (C) 2001-2002  Philip W. L. Fong

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

package java.lang;

import aegis.*;
import java.io.*;
import java.util.*;

public final class System {
    public static final InputStream in;
    public static final PrintStream out;
    public static final PrintStream err;
    private static SecurityManager securityManager;
    private static Properties properties;
    static {
	securityManager = null;
	properties = getDefaultProperties();
	in = new FileInputStream(FileDescriptor.in);
	out = new PrintStream(new FileOutputStream(FileDescriptor.out));
	err = new PrintStream(new FileOutputStream(FileDescriptor.err));
    }
    private System() { }
    public static void setIn(InputStream is) {
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPermission(new RuntimePermission("setIO"));
	throw new FeatureNotYetImplementedError();
    }
    public static void setOut(PrintStream os) {
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPermission(new RuntimePermission("setIO"));
	throw new FeatureNotYetImplementedError();
    }
    public static void setErr(PrintStream es) {
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPermission(new RuntimePermission("setIO"));
	throw new FeatureNotYetImplementedError();
    }
    public static void setSecurityManager(SecurityManager s) {
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPermission(new RuntimePermission("setSecurityManager"));
	securityManager = s;
    }
    public static SecurityManager getSecurityManager() {
	return securityManager;
    }
    public static native long currentTimeMillis();
    public static native void arraycopy(Object src,
					int src_position,
					Object dst,
					int dst_position,
					int length);
    public static native int identityHashCode(Object x);
    public static Properties getProperties() {
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPropertiesAccess();
	return properties;
    }
    public static void setProperties(Properties props) {
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPropertiesAccess();
	properties = props;
    }
    public static String getProperty(String key) {
	return getProperty(key, null);
    }
    public static String getProperty(String key, String def) {
	if (key == null)
	    throw new NullPointerException();
	if (key.length() == 0)
	    throw new IllegalArgumentException();
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPropertiesAccess(key);
	if (properties != null)
	    return properties.getProperty(key, def);
	else if (key.equals("java.library.path"))
	    return getLibraryPath();
	else if (key.equals("aegis.library.prefix"))
	    return getLibraryPrefix();
	else if (key.equals("aegis.library.suffix"))
	    return getLibrarySuffix();
	else if (key.equals("path.separator"))
	    return getPathSeparator();
	else if (key.equals("file.separator"))
	    return getFileSeparator();
	else if (key.equals("line.separator"))
	    return getLineSeparator();
	else if (key.equals("os.name"))
	    return getOsName();
	else if (key.equals("os.arch"))
	    return getOsArch();
	else if (key.equals("os.version"))
	    return getOsVersion();
	else if (key.equals("user.name"))
	    return getUserName();
	else if (key.equals("user.home"))
	    return getUserHome();
	else if (key.equals("user.dir"))
	    return getUserDir();
	else if (key.equals("user.language"))
	    return getUserLanguage();
	else if (key.equals("user.region"))
	    return getUserRegion();
	else if (key.equals("user.variant"))
	    return getUserVariant();
	else
	    return def;
    }
    public static String setProperty(String key, String value) {
	if (key == null)
	    throw new NullPointerException();
	if (key.length() == 0)
	    throw new IllegalArgumentException();
	SecurityManager m = getSecurityManager();
	if (m != null)
	    m.checkPermission(new PropertyPermission(key, "write"));
	return (String) properties.setProperty(key, value);
    }
    /**
     * \todo Not implemented yet.
     */
    public static void exit(int status) {
	throw new FeatureNotYetImplementedError();
    }
    public static void gc() {
	Runtime.getRuntime().gc();
    }
    /**
     * \todo Not implemented yet.
     */
    public static void runFinalization() {
	// XXX throw new FeatureNotYetImplementedError();
    }
    public static void load(String filename) {
	if (filename == null)
	    throw new NullPointerException();
	Runtime.load(filename, getCaller(1));
    }
    public static void loadLibrary(String libname) {
	if (libname == null)
	    throw new NullPointerException();
	Runtime.loadLibrary(libname, getCaller(1));
    }
    public static String mapLibraryName(String libname) {
	String prefix = getProperty("aegis.library.prefix");
	String suffix = getProperty("aegis.library.suffix");
	return prefix + libname + suffix;
    }
    /**
     * \todo Should urge Classpath development team to remove
     *       this unnecessary bootstrap dependency.
     */
    private static Properties getDefaultProperties() {
	Properties p = new Properties();
	p.setProperty("java.library.path", getLibraryPath());
	p.setProperty("aegis.library.prefix", getLibraryPrefix());
	p.setProperty("aegis.library.suffix", getLibrarySuffix());
	p.setProperty("path.separator", getPathSeparator());
	p.setProperty("file.separator", getFileSeparator());
	p.setProperty("line.separator", getLineSeparator());
	p.setProperty("os.name", getOsName());
	p.setProperty("os.arch", getOsArch());
	p.setProperty("os.version", getOsVersion());
	p.setProperty("user.name", getUserName());
	p.setProperty("user.home", getUserHome());
	p.setProperty("user.dir", getUserDir());
	p.setProperty("user.language", getUserLanguage());
	p.setProperty("user.region", getUserRegion());
	p.setProperty("user.variant", getUserVariant());

	// Common encoding aliases. See gnu.java.io.EncodingManager.
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-1",
		       "8859_1");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-2",
		       "8859_2");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-3",
		       "8859_3");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-4",
		       "8859_4");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-5",
		       "8859_5");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-6",
		       "8859_6");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-7",
		       "8859_7");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-8",
		       "8859_8");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.ISO-8859-9",
		       "8859_9");
	
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-1",
		       "8859_1");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-2",
		       "8859_2");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-3",
		       "8859_3");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-4",
		       "8859_4");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-5",
		       "8859_5");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-6",
		       "8859_6");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-7",
		       "8859_7");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-8",
		       "8859_8");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-8859-9",
		       "8859_9");
	
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_1",
		       "8859_1");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_2",
		       "8859_2");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_3",
		       "8859_3");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_4",
		       "8859_4");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_5",
		       "8859_5");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_6",
		       "8859_6");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_7",
		       "8859_7");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_8",
		       "8859_8");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso8859_9",
		       "8859_9");
	
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-1",
		       "8859_1");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-2",
		       "8859_2");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-3",
		       "8859_3");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-4",
		       "8859_4");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-5",
		       "8859_5");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-6",
		       "8859_6");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-7",
		       "8859_7");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-8",
		       "8859_8");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.iso-latin-9",
		       "8859_9");
	
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin1",
		       "8859_1");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin2",
		       "8859_2");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin3",
		       "8859_3");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin4",
		       "8859_4");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin5",
		       "8859_5");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin6",
		       "8859_6");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin7",
		       "8859_7");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin8",
		       "8859_8");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.latin9",
		       "8859_9");
	
	p.setProperty ("gnu.java.io.encoding_scheme_alias.UTF-8",
		       "UTF8");
	p.setProperty ("gnu.java.io.encoding_scheme_alias.utf-8",
		       "UTF8");

	return p;
    }
    static native String getLibraryPath();
    static native String getLibraryPrefix();
    static native String getLibrarySuffix();
    static native String getFileSeparator();
    static native String getPathSeparator();
    static native String getLineSeparator();
    static native String getOsName();
    static native String getOsArch();
    static native String getOsVersion();
    static native String getUserName();
    static native String getUserHome();
    static native String getUserDir();
    static native String getUserLanguage();
    static native String getUserRegion();
    static native String getUserVariant();
    static native Class getCaller(int i);
}