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	/*
	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* 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.lang.reflect.AnnotatedElement;
	import java.io.InputStream;
	import java.util.Enumeration;

	import java.util.StringTokenizer;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.net.URL;
	import java.net.MalformedURLException;
	import java.security.AccessController;
	import java.security.PrivilegedAction;

	import java.util.jar.JarInputStream;
	import java.util.jar.Manifest;
	import java.util.jar.Attributes;
	import java.util.jar.Attributes.Name;
	import java.util.jar.JarException;
	import java.util.Map;
	import java.util.HashMap;
	import java.util.Iterator;

	import sun.net.www.ParseUtil;
	import sun.reflect.CallerSensitive;
	import sun.reflect.Reflection;

	import java.lang.annotation.Annotation;

	/**
	* {@code Package} objects contain version information
	* about the implementation and specification of a Java package.
	* This versioning information is retrieved and made available
	* by the {@link ClassLoader} instance that
	* loaded the class(es). Typically, it is stored in the manifest that is
	* distributed with the classes.
	*
	* <p>The set of classes that make up the package may implement a
	* particular specification and if so the specification title, version number,
	* and vendor strings identify that specification.
	* An application can ask if the package is
	* compatible with a particular version, see the {@link
	* #isCompatibleWith isCompatibleWith}
	* method for details.
	*
	* <p>Specification version numbers use a syntax that consists of nonnegative
	* decimal integers separated by periods ".", for example "2.0" or
	* "1.2.3.4.5.6.7". This allows an extensible number to be used to represent
	* major, minor, micro, etc. versions. The version specification is described
	* by the following formal grammar:
	* <blockquote>
	* <dl>
	* <dt><i>SpecificationVersion:</i>
	* <dd><i>Digits RefinedVersion<sub>opt</sub></i>

	* <dt><i>RefinedVersion:</i>
	* <dd>{@code .} <i>Digits</i>
	* <dd>{@code .} <i>Digits RefinedVersion</i>
	*
	* <dt><i>Digits:</i>
	* <dd><i>Digit</i>
	* <dd><i>Digits</i>
	*
	* <dt><i>Digit:</i>
	* <dd>any character for which {@link Character#isDigit} returns {@code true},
	* e.g. 0, 1, 2, ...
	* </dl>
	* </blockquote>
	*
	* <p>The implementation title, version, and vendor strings identify an
	* implementation and are made available conveniently to enable accurate
	* reporting of the packages involved when a problem occurs. The contents
	* all three implementation strings are vendor specific. The
	* implementation version strings have no specified syntax and should
	* only be compared for equality with desired version identifiers.
	*
	* <p>Within each {@code ClassLoader} instance all classes from the same
	* java package have the same Package object. The static methods allow a package
	* to be found by name or the set of all packages known to the current class
	* loader to be found.
	*
	* @see ClassLoader#definePackage
	*/
	public class Package implements java.lang.reflect.AnnotatedElement {
	/**
	* Return the name of this package.
	*
	* @return The fully-qualified name of this package as defined in section 6.5.3 of
	* <cite>The Java™ Language Specification</cite>,
	* for example, {@code java.lang}
	*/
	public String getName() {
	return pkgName;
	}


	/**
	* Return the title of the specification that this package implements.
	* @return the specification title, null is returned if it is not known.
	*/
	public String getSpecificationTitle() {
	return specTitle;
	}

	/**
	* Returns the version number of the specification
	* that this package implements.
	* This version string must be a sequence of nonnegative decimal
	* integers separated by "."'s and may have leading zeros.
	* When version strings are compared the most significant
	* numbers are compared.
	* @return the specification version, null is returned if it is not known.
	*/
	public String getSpecificationVersion() {
	return specVersion;
	}

	/**
	* Return the name of the organization, vendor,
	* or company that owns and maintains the specification
	* of the classes that implement this package.
	* @return the specification vendor, null is returned if it is not known.
	*/
	public String getSpecificationVendor() {
	return specVendor;
	}

	/**
	* Return the title of this package.
	* @return the title of the implementation, null is returned if it is not known.
	*/
	public String getImplementationTitle() {
	return implTitle;
	}

	/**
	* Return the version of this implementation. It consists of any string
	* assigned by the vendor of this implementation and does
	* not have any particular syntax specified or expected by the Java
	* runtime. It may be compared for equality with other
	* package version strings used for this implementation
	* by this vendor for this package.
	* @return the version of the implementation, null is returned if it is not known.
	*/
	public String getImplementationVersion() {
	return implVersion;
	}

	/**
	* Returns the name of the organization,
	* vendor or company that provided this implementation.
	* @return the vendor that implemented this package..
	*/
	public String getImplementationVendor() {
	return implVendor;
	}

	/**
	* Returns true if this package is sealed.
	*
	* @return true if the package is sealed, false otherwise
	*/
	public boolean isSealed() {
	return sealBase != null;
	}

	/**
	* Returns true if this package is sealed with respect to the specified
	* code source url.
	*
	* @param url the code source url
	* @return true if this package is sealed with respect to url
	*/
	public boolean isSealed(URL url) {
	return url.equals(sealBase);
	}

	/**
	* Compare this package's specification version with a
	* desired version. It returns true if
	* this packages specification version number is greater than or equal
	* to the desired version number. <p>
	*
	* Version numbers are compared by sequentially comparing corresponding
	* components of the desired and specification strings.
	* Each component is converted as a decimal integer and the values
	* compared.
	* If the specification value is greater than the desired
	* value true is returned. If the value is less false is returned.
	* If the values are equal the period is skipped and the next pair of
	* components is compared.
	*
	* @param desired the version string of the desired version.
	* @return true if this package's version number is greater
	* than or equal to the desired version number
	*
	* @exception NumberFormatException if the desired or current version
	* is not of the correct dotted form.
	*/
	public boolean isCompatibleWith(String desired)
	throws NumberFormatException
	{
	if (specVersion == null \|\| specVersion.length() < 1) {
	throw new NumberFormatException("Empty version string");
	}

	String [] sa = specVersion.split("\\.", -1);
	int [] si = new int[sa.length];
	for (int i = 0; i < sa.length; i++) {
	si[i] = Integer.parseInt(sa[i]);
	if (si[i] < 0)
	throw NumberFormatException.forInputString("" + si[i]);
	}

	String [] da = desired.split("\\.", -1);
	int [] di = new int[da.length];
	for (int i = 0; i < da.length; i++) {
	di[i] = Integer.parseInt(da[i]);
	if (di[i] < 0)
	throw NumberFormatException.forInputString("" + di[i]);
	}

	int len = Math.max(di.length, si.length);
	for (int i = 0; i < len; i++) {
	int d = (i < di.length ? di[i] : 0);
	int s = (i < si.length ? si[i] : 0);
	if (s < d)
	return false;
	if (s > d)
	return true;
	}
	return true;
	}

	/**
	* Find a package by name in the callers {@code ClassLoader} instance.
	* The callers {@code ClassLoader} instance is used to find the package
	* instance corresponding to the named class. If the callers
	* {@code ClassLoader} instance is null then the set of packages loaded
	* by the system {@code ClassLoader} instance is searched to find the
	* named package. <p>
	*
	* Packages have attributes for versions and specifications only if the class
	* loader created the package instance with the appropriate attributes. Typically,
	* those attributes are defined in the manifests that accompany the classes.
	*
	* @param name a package name, for example, java.lang.
	* @return the package of the requested name. It may be null if no package
	* information is available from the archive or codebase.
	*/
	@CallerSensitive
	public static Package getPackage(String name) {
	ClassLoader l = ClassLoader.getClassLoader(Reflection.getCallerClass());
	if (l != null) {
	return l.getPackage(name);
	} else {
	return getSystemPackage(name);
	}
	}

	/**
	* Get all the packages currently known for the caller's {@code ClassLoader}
	* instance. Those packages correspond to classes loaded via or accessible by
	* name to that {@code ClassLoader} instance. If the caller's
	* {@code ClassLoader} instance is the bootstrap {@code ClassLoader}
	* instance, which may be represented by {@code null} in some implementations,
	* only packages corresponding to classes loaded by the bootstrap
	* {@code ClassLoader} instance will be returned.
	*
	* @return a new array of packages known to the callers {@code ClassLoader}
	* instance. An zero length array is returned if none are known.
	*/
	@CallerSensitive
	public static Package[] getPackages() {
	ClassLoader l = ClassLoader.getClassLoader(Reflection.getCallerClass());
	if (l != null) {
	return l.getPackages();
	} else {
	return getSystemPackages();
	}
	}

	/**
	* Get the package for the specified class.
	* The class's class loader is used to find the package instance
	* corresponding to the specified class. If the class loader
	* is the bootstrap class loader, which may be represented by
	* {@code null} in some implementations, then the set of packages
	* loaded by the bootstrap class loader is searched to find the package.
	* <p>
	* Packages have attributes for versions and specifications only
	* if the class loader created the package
	* instance with the appropriate attributes. Typically those
	* attributes are defined in the manifests that accompany
	* the classes.
	*
	* @param c the class to get the package of.
	* @return the package of the class. It may be null if no package
	* information is available from the archive or codebase. */
	static Package getPackage(Class<?> c) {
	String name = c.getName();
	int i = name.lastIndexOf('.');
	if (i != -1) {
	name = name.substring(0, i);
	ClassLoader cl = c.getClassLoader();
	if (cl != null) {
	return cl.getPackage(name);
	} else {
	return getSystemPackage(name);
	}
	} else {
	return null;
	}
	}

	/**
	* Return the hash code computed from the package name.
	* @return the hash code computed from the package name.
	*/
	public int hashCode(){
	return pkgName.hashCode();
	}

	/**
	* Returns the string representation of this Package.
	* Its value is the string "package " and the package name.
	* If the package title is defined it is appended.
	* If the package version is defined it is appended.
	* @return the string representation of the package.
	*/
	public String toString() {
	String spec = specTitle;
	String ver = specVersion;
	if (spec != null && spec.length() > 0)
	spec = ", " + spec;
	else
	spec = "";
	if (ver != null && ver.length() > 0)
	ver = ", version " + ver;
	else
	ver = "";
	return "package " + pkgName + spec + ver;
	}

	private Class<?> getPackageInfo() {
	if (packageInfo == null) {
	try {
	packageInfo = Class.forName(pkgName + ".package-info", false, loader);
	} catch (ClassNotFoundException ex) {
	// store a proxy for the package info that has no annotations
	class PackageInfoProxy {}
	packageInfo = PackageInfoProxy.class;
	}
	}
	return packageInfo;
	}

	/**
	* @throws NullPointerException {@inheritDoc}
	* @since 1.5
	*/
	public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
	return getPackageInfo().getAnnotation(annotationClass);
	}

	/**
	* {@inheritDoc}
	* @throws NullPointerException {@inheritDoc}
	* @since 1.5
	*/
	@Override
	public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
	return AnnotatedElement.super.isAnnotationPresent(annotationClass);
	}

	/**
	* @throws NullPointerException {@inheritDoc}
	* @since 1.8
	*/
	@Override
	public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
	return getPackageInfo().getAnnotationsByType(annotationClass);
	}

	/**
	* @since 1.5
	*/
	public Annotation[] getAnnotations() {
	return getPackageInfo().getAnnotations();
	}

	/**
	* @throws NullPointerException {@inheritDoc}
	* @since 1.8
	*/
	@Override
	public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
	return getPackageInfo().getDeclaredAnnotation(annotationClass);
	}

	/**
	* @throws NullPointerException {@inheritDoc}
	* @since 1.8
	*/
	@Override
	public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
	return getPackageInfo().getDeclaredAnnotationsByType(annotationClass);
	}

	/**
	* @since 1.5
	*/
	public Annotation[] getDeclaredAnnotations() {
	return getPackageInfo().getDeclaredAnnotations();
	}

	/**
	* Construct a package instance with the specified version
	* information.
	* @param name the name of the package
	* @param spectitle the title of the specification
	* @param specversion the version of the specification
	* @param specvendor the organization that maintains the specification
	* @param impltitle the title of the implementation
	* @param implversion the version of the implementation
	* @param implvendor the organization that maintains the implementation
	*/
	Package(String name,
	String spectitle, String specversion, String specvendor,
	String impltitle, String implversion, String implvendor,
	URL sealbase, ClassLoader loader)
	{
	pkgName = name;
	implTitle = impltitle;
	implVersion = implversion;
	implVendor = implvendor;
	specTitle = spectitle;
	specVersion = specversion;
	specVendor = specvendor;
	sealBase = sealbase;
	this.loader = loader;
	}

	/*
	* Construct a package using the attributes from the specified manifest.
	*
	* @param name the package name
	* @param man the optional manifest for the package
	* @param url the optional code source url for the package
	*/
	private Package(String name, Manifest man, URL url, ClassLoader loader) {
	String path = name.replace('.', '/').concat("/");
	String sealed = null;
	String specTitle= null;
	String specVersion= null;
	String specVendor= null;
	String implTitle= null;
	String implVersion= null;
	String implVendor= null;
	URL sealBase= null;
	Attributes attr = man.getAttributes(path);
	if (attr != null) {
	specTitle = attr.getValue(Name.SPECIFICATION_TITLE);
	specVersion = attr.getValue(Name.SPECIFICATION_VERSION);
	specVendor = attr.getValue(Name.SPECIFICATION_VENDOR);
	implTitle = attr.getValue(Name.IMPLEMENTATION_TITLE);
	implVersion = attr.getValue(Name.IMPLEMENTATION_VERSION);
	implVendor = attr.getValue(Name.IMPLEMENTATION_VENDOR);
	sealed = attr.getValue(Name.SEALED);
	}
	attr = man.getMainAttributes();
	if (attr != null) {
	if (specTitle == null) {
	specTitle = attr.getValue(Name.SPECIFICATION_TITLE);
	}
	if (specVersion == null) {
	specVersion = attr.getValue(Name.SPECIFICATION_VERSION);
	}
	if (specVendor == null) {
	specVendor = attr.getValue(Name.SPECIFICATION_VENDOR);
	}
	if (implTitle == null) {
	implTitle = attr.getValue(Name.IMPLEMENTATION_TITLE);
	}
	if (implVersion == null) {
	implVersion = attr.getValue(Name.IMPLEMENTATION_VERSION);
	}
	if (implVendor == null) {
	implVendor = attr.getValue(Name.IMPLEMENTATION_VENDOR);
	}
	if (sealed == null) {
	sealed = attr.getValue(Name.SEALED);
	}
	}
	if ("true".equalsIgnoreCase(sealed)) {
	sealBase = url;
	}
	pkgName = name;
	this.specTitle = specTitle;
	this.specVersion = specVersion;
	this.specVendor = specVendor;
	this.implTitle = implTitle;
	this.implVersion = implVersion;
	this.implVendor = implVendor;
	this.sealBase = sealBase;
	this.loader = loader;
	}

	/*
	* Returns the loaded system package for the specified name.
	*/
	static Package getSystemPackage(String name) {
	synchronized (pkgs) {
	Package pkg = pkgs.get(name);
	if (pkg == null) {
	name = name.replace('.', '/').concat("/");
	String fn = getSystemPackage0(name);
	if (fn != null) {
	pkg = defineSystemPackage(name, fn);
	}
	}
	return pkg;
	}
	}

	/*
	* Return an array of loaded system packages.
	*/
	static Package[] getSystemPackages() {
	// First, update the system package map with new package names
	String[] names = getSystemPackages0();
	synchronized (pkgs) {
	for (int i = 0; i < names.length; i++) {
	defineSystemPackage(names[i], getSystemPackage0(names[i]));
	}
	return pkgs.values().toArray(new Package[pkgs.size()]);
	}
	}

	private static Package defineSystemPackage(final String iname,
	final String fn)
	{
	return AccessController.doPrivileged(new PrivilegedAction<Package>() {
	public Package run() {
	String name = iname;
	// Get the cached code source url for the file name
	URL url = urls.get(fn);
	if (url == null) {
	// URL not found, so create one
	File file = new File(fn);
	try {
	url = ParseUtil.fileToEncodedURL(file);
	} catch (MalformedURLException e) {
	}
	if (url != null) {
	urls.put(fn, url);
	// If loading a JAR file, then also cache the manifest
	if (file.isFile()) {
	mans.put(fn, loadManifest(fn));
	}
	}
	}
	// Convert to "."-separated package name
	name = name.substring(0, name.length() - 1).replace('/', '.');
	Package pkg;
	Manifest man = mans.get(fn);
	if (man != null) {
	pkg = new Package(name, man, url, null);
	} else {
	pkg = new Package(name, null, null, null,
	null, null, null, null, null);
	}
	pkgs.put(name, pkg);
	return pkg;
	}
	});
	}

	/*
	* Returns the Manifest for the specified JAR file name.
	*/
	private static Manifest loadManifest(String fn) {
	try (FileInputStream fis = new FileInputStream(fn);
	JarInputStream jis = new JarInputStream(fis, false))
	{
	return jis.getManifest();
	} catch (IOException e) {
	return null;
	}
	}

	// The map of loaded system packages
	private static Map<String, Package> pkgs = new HashMap<>(31);

	// Maps each directory or zip file name to its corresponding url
	private static Map<String, URL> urls = new HashMap<>(10);

	// Maps each code source url for a jar file to its manifest
	private static Map<String, Manifest> mans = new HashMap<>(10);

	private static native String getSystemPackage0(String name);
	private static native String[] getSystemPackages0();

	/*
	* Private storage for the package name and attributes.
	*/
	private final String pkgName;
	private final String specTitle;
	private final String specVersion;
	private final String specVendor;
	private final String implTitle;
	private final String implVersion;
	private final String implVendor;
	private final URL sealBase;
	private transient final ClassLoader loader;
	private transient Class<?> packageInfo;
	}

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