/*
 * Copyright (c) OSGi Alliance (2000, 2009). All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.osgi.framework;

/**
 * Defines standard names for the OSGi environment system properties, service
 * properties, and Manifest header attribute keys.
 * 
 * <p>
 * The values associated with these keys are of type
 * <code>String</code>, unless otherwise indicated.
 * 
 * @since 1.1
 * @version $Revision: 6552 $
 */

public interface Constants {
	/**
	 * Location identifier of the OSGi <i>system bundle </i>, which is defined
	 * to be &quot;System Bundle&quot;.
	 */
	public static final String	SYSTEM_BUNDLE_LOCATION					= "System Bundle";

	/**
	 * Alias for the symbolic name of the OSGi <i>system bundle </i>. It is
	 * defined to be &quot;system.bundle&quot;.
	 * 
	 * @since 1.3
	 */
	public static final String	SYSTEM_BUNDLE_SYMBOLICNAME				= "system.bundle";

	/**
	 * Manifest header identifying the bundle's category.
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_CATEGORY							= "Bundle-Category";

	/**
	 * Manifest header identifying a list of directories and embedded JAR files,
	 * which are bundle resources used to extend the bundle's classpath.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_CLASSPATH						= "Bundle-ClassPath";

	/**
	 * Manifest header identifying the bundle's copyright information.
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_COPYRIGHT						= "Bundle-Copyright";

	/**
	 * Manifest header containing a brief description of the bundle's
	 * functionality.
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_DESCRIPTION						= "Bundle-Description";

	/**
	 * Manifest header identifying the bundle's name.
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_NAME								= "Bundle-Name";

	/**
	 * Manifest header identifying a number of hardware environments and the
	 * native language code libraries that the bundle is carrying for each of
	 * these environments.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_NATIVECODE						= "Bundle-NativeCode";

	/**
	 * Manifest header identifying the packages that the bundle offers to the
	 * Framework for export.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	EXPORT_PACKAGE							= "Export-Package";

	/**
	 * Manifest header identifying the fully qualified class names of the
	 * services that the bundle may register (used for informational purposes
	 * only).
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @deprecated As of 1.2.
	 */
	public static final String	EXPORT_SERVICE							= "Export-Service";

	/**
	 * Manifest header identifying the packages on which the bundle depends.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	IMPORT_PACKAGE							= "Import-Package";

	/**
	 * Manifest header identifying the packages that the bundle may dynamically
	 * import during execution.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.2
	 */
	public static final String	DYNAMICIMPORT_PACKAGE					= "DynamicImport-Package";

	/**
	 * Manifest header identifying the fully qualified class names of the
	 * services that the bundle requires (used for informational purposes only).
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @deprecated As of 1.2.
	 */
	public static final String	IMPORT_SERVICE							= "Import-Service";

	/**
	 * Manifest header identifying the bundle's vendor.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_VENDOR							= "Bundle-Vendor";

	/**
	 * Manifest header identifying the bundle's version.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_VERSION							= "Bundle-Version";

	/**
	 * Manifest header identifying the bundle's documentation URL, from which
	 * further information about the bundle may be obtained.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_DOCURL							= "Bundle-DocURL";

	/**
	 * Manifest header identifying the contact address where problems with the
	 * bundle may be reported; for example, an email address.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_CONTACTADDRESS					= "Bundle-ContactAddress";

	/**
	 * Manifest header attribute identifying the bundle's activator class.
	 * 
	 * <p>
	 * If present, this header specifies the name of the bundle resource class
	 * that implements the <code>BundleActivator</code> interface and whose
	 * <code>start</code> and <code>stop</code> methods are called by the
	 * Framework when the bundle is started and stopped, respectively.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_ACTIVATOR						= "Bundle-Activator";

	/**
	 * Manifest header identifying the location from which a new bundle version
	 * is obtained during a bundle update operation.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 */
	public static final String	BUNDLE_UPDATELOCATION					= "Bundle-UpdateLocation";

	/**
	 * Manifest header attribute identifying the version of a package specified
	 * in the Export-Package or Import-Package manifest header.
	 * 
	 * @deprecated As of 1.3. This has been replaced by
	 *             {@link #VERSION_ATTRIBUTE}.
	 */
	public static final String	PACKAGE_SPECIFICATION_VERSION			= "specification-version";

	/**
	 * Manifest header attribute identifying the processor required to run
	 * native bundle code specified in the Bundle-NativeCode manifest header).
	 * 
	 * <p>
	 * The attribute value is encoded in the Bundle-NativeCode manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-NativeCode: http.so ; processor=x86 ...
	 * </pre>
	 * 
	 * @see #BUNDLE_NATIVECODE
	 */
	public static final String	BUNDLE_NATIVECODE_PROCESSOR				= "processor";

	/**
	 * Manifest header attribute identifying the operating system required to
	 * run native bundle code specified in the Bundle-NativeCode manifest
	 * header).
	 * <p>
	 * The attribute value is encoded in the Bundle-NativeCode manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-NativeCode: http.so ; osname=Linux ...
	 * </pre>
	 * 
	 * @see #BUNDLE_NATIVECODE
	 */
	public static final String	BUNDLE_NATIVECODE_OSNAME				= "osname";

	/**
	 * Manifest header attribute identifying the operating system version
	 * required to run native bundle code specified in the Bundle-NativeCode
	 * manifest header).
	 * <p>
	 * The attribute value is encoded in the Bundle-NativeCode manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-NativeCode: http.so ; osversion=&quot;2.34&quot; ...
	 * </pre>
	 * 
	 * @see #BUNDLE_NATIVECODE
	 */
	public static final String	BUNDLE_NATIVECODE_OSVERSION				= "osversion";

	/**
	 * Manifest header attribute identifying the language in which the native
	 * bundle code is written specified in the Bundle-NativeCode manifest
	 * header. See ISO 639 for possible values.
	 * <p>
	 * The attribute value is encoded in the Bundle-NativeCode manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-NativeCode: http.so ; language=nl_be ...
	 * </pre>
	 * 
	 * @see #BUNDLE_NATIVECODE
	 */
	public static final String	BUNDLE_NATIVECODE_LANGUAGE				= "language";

	/**
	 * Manifest header identifying the required execution environment for the
	 * bundle. The service platform may run this bundle if any of the execution
	 * environments named in this header matches one of the execution
	 * environments it implements.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.2
	 */
	public static final String	BUNDLE_REQUIREDEXECUTIONENVIRONMENT		= "Bundle-RequiredExecutionEnvironment";

	/**
	 * Manifest header identifying the bundle's symbolic name.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.3
	 */
	public final static String	BUNDLE_SYMBOLICNAME						= "Bundle-SymbolicName";

	/**
	 * Manifest header directive identifying whether a bundle is a singleton.
	 * The default value is <code>false</code>.
	 * 
	 * <p>
	 * The directive value is encoded in the Bundle-SymbolicName manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-SymbolicName: com.acme.module.test; singleton:=true
	 * </pre>
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @see #BUNDLE_SYMBOLICNAME
	 * @since 1.3
	 */
	public final static String	SINGLETON_DIRECTIVE						= "singleton";

	/**
	 * Manifest header directive identifying if and when a fragment may attach
	 * to a host bundle. The default value is
	 * {@link #FRAGMENT_ATTACHMENT_ALWAYS always}.
	 * 
	 * <p>
	 * The directive value is encoded in the Bundle-SymbolicName manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-SymbolicName: com.acme.module.test; fragment-attachment:=&quot;never&quot;
	 * </pre>
	 * 
	 * @see #BUNDLE_SYMBOLICNAME
	 * @see #FRAGMENT_ATTACHMENT_ALWAYS
	 * @see #FRAGMENT_ATTACHMENT_RESOLVETIME
	 * @see #FRAGMENT_ATTACHMENT_NEVER
	 * @since 1.3
	 */
	public final static String	FRAGMENT_ATTACHMENT_DIRECTIVE			= "fragment-attachment";

	/**
	 * Manifest header directive value identifying a fragment attachment type of
	 * always. A fragment attachment type of always indicates that fragments are
	 * allowed to attach to the host bundle at any time (while the host is
	 * resolved or during the process of resolving the host bundle).
	 * 
	 * <p>
	 * The directive value is encoded in the Bundle-SymbolicName manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-SymbolicName: com.acme.module.test; fragment-attachment:=&quot;always&quot;
	 * </pre>
	 * 
	 * @see #FRAGMENT_ATTACHMENT_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	FRAGMENT_ATTACHMENT_ALWAYS				= "always";

	/**
	 * Manifest header directive value identifying a fragment attachment type of
	 * resolve-time. A fragment attachment type of resolve-time indicates that
	 * fragments are allowed to attach to the host bundle only during the
	 * process of resolving the host bundle.
	 * 
	 * <p>
	 * The directive value is encoded in the Bundle-SymbolicName manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-SymbolicName: com.acme.module.test; fragment-attachment:=&quot;resolve-time&quot;
	 * </pre>
	 * 
	 * @see #FRAGMENT_ATTACHMENT_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	FRAGMENT_ATTACHMENT_RESOLVETIME			= "resolve-time";

	/**
	 * Manifest header directive value identifying a fragment attachment type of
	 * never. A fragment attachment type of never indicates that no fragments
	 * are allowed to attach to the host bundle at any time.
	 * 
	 * <p>
	 * The directive value is encoded in the Bundle-SymbolicName manifest header
	 * like:
	 * 
	 * <pre>
	 *     Bundle-SymbolicName: com.acme.module.test; fragment-attachment:=&quot;never&quot;
	 * </pre>
	 * 
	 * @see #FRAGMENT_ATTACHMENT_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	FRAGMENT_ATTACHMENT_NEVER				= "never";

	/**
	 * Manifest header identifying the base name of the bundle's localization
	 * entries.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @see #BUNDLE_LOCALIZATION_DEFAULT_BASENAME
	 * @since 1.3
	 */
	public final static String	BUNDLE_LOCALIZATION						= "Bundle-Localization";

	/**
	 * Default value for the <code>Bundle-Localization</code> manifest header.
	 * 
	 * @see #BUNDLE_LOCALIZATION
	 * @since 1.3
	 */
	public final static String	BUNDLE_LOCALIZATION_DEFAULT_BASENAME	= "OSGI-INF/l10n/bundle";

	/**
	 * Manifest header identifying the symbolic names of other bundles required
	 * by the bundle.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.3
	 */
	public final static String	REQUIRE_BUNDLE							= "Require-Bundle";

	/**
	 * Manifest header attribute identifying a range of versions for a bundle
	 * specified in the <code>Require-Bundle</code> or
	 * <code>Fragment-Host</code> manifest headers. The default value is
	 * <code>0.0.0</code>.
	 * 
	 * <p>
	 * The attribute value is encoded in the Require-Bundle manifest header
	 * like:
	 * 
	 * <pre>
	 *     Require-Bundle: com.acme.module.test; bundle-version=&quot;1.1&quot;
	 *     Require-Bundle: com.acme.module.test; bundle-version=&quot;[1.0,2.0)&quot;
	 * </pre>
	 * 
	 * <p>
	 * The bundle-version attribute value uses a mathematical interval notation
	 * to specify a range of bundle versions. A bundle-version attribute value
	 * specified as a single version means a version range that includes any
	 * bundle version greater than or equal to the specified version.
	 * 
	 * @see #REQUIRE_BUNDLE
	 * @since 1.3
	 */
	public static final String	BUNDLE_VERSION_ATTRIBUTE				= "bundle-version";

	/**
	 * Manifest header identifying the symbolic name of another bundle for which
	 * that the bundle is a fragment.
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.3
	 */
	public final static String	FRAGMENT_HOST							= "Fragment-Host";

	/**
	 * Manifest header attribute is used for selection by filtering based upon
	 * system properties.
	 * 
	 * <p>
	 * The attribute value is encoded in manifest headers like:
	 * 
	 * <pre>
	 *     Bundle-NativeCode: libgtk.so; selection-filter=&quot;(ws=gtk)&quot;; ...
	 * </pre>
	 * 
	 * @see #BUNDLE_NATIVECODE
	 * @since 1.3
	 */
	public final static String	SELECTION_FILTER_ATTRIBUTE				= "selection-filter";

	/**
	 * Manifest header identifying the bundle manifest version. A bundle
	 * manifest may express the version of the syntax in which it is written by
	 * specifying a bundle manifest version. Bundles exploiting OSGi Release 4,
	 * or later, syntax must specify a bundle manifest version.
	 * <p>
	 * The bundle manifest version defined by OSGi Release 4 or, more
	 * specifically, by version 1.3 of the OSGi Core Specification is "2".
	 * 
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.3
	 */
	public final static String	BUNDLE_MANIFESTVERSION					= "Bundle-ManifestVersion";

	/**
	 * Manifest header attribute identifying the version of a package specified
	 * in the Export-Package or Import-Package manifest header.
	 * 
	 * <p>
	 * The attribute value is encoded in the Export-Package or Import-Package
	 * manifest header like:
	 * 
	 * <pre>
	 *     Import-Package: org.osgi.framework; version=&quot;1.1&quot;
	 * </pre>
	 * 
	 * @see #EXPORT_PACKAGE
	 * @see #IMPORT_PACKAGE
	 * @since 1.3
	 */
	public final static String	VERSION_ATTRIBUTE						= "version";

	/**
	 * Manifest header attribute identifying the symbolic name of a bundle that
	 * exports a package specified in the Import-Package manifest header.
	 * 
	 * <p>
	 * The attribute value is encoded in the Import-Package manifest header
	 * like:
	 * 
	 * <pre>
	 *     Import-Package: org.osgi.framework; bundle-symbolic-name=&quot;com.acme.module.test&quot;
	 * </pre>
	 * 
	 * @see #IMPORT_PACKAGE
	 * @since 1.3
	 */
	public final static String	BUNDLE_SYMBOLICNAME_ATTRIBUTE			= "bundle-symbolic-name";

	/**
	 * Manifest header directive identifying the resolution type in the
	 * Import-Package or Require-Bundle manifest header. The default value is
	 * {@link #RESOLUTION_MANDATORY mandatory}.
	 * 
	 * <p>
	 * The directive value is encoded in the Import-Package or Require-Bundle
	 * manifest header like:
	 * 
	 * <pre>
	 *     Import-Package: org.osgi.framework; resolution:=&quot;optional&quot;
	 *     Require-Bundle: com.acme.module.test; resolution:=&quot;optional&quot;
	 * </pre>
	 * 
	 * @see #IMPORT_PACKAGE
	 * @see #REQUIRE_BUNDLE
	 * @see #RESOLUTION_MANDATORY
	 * @see #RESOLUTION_OPTIONAL
	 * @since 1.3
	 */
	public final static String	RESOLUTION_DIRECTIVE					= "resolution";

	/**
	 * Manifest header directive value identifying a mandatory resolution type.
	 * A mandatory resolution type indicates that the import package or require
	 * bundle must be resolved when the bundle is resolved. If such an import or
	 * require bundle cannot be resolved, the module fails to resolve.
	 * 
	 * <p>
	 * The directive value is encoded in the Import-Package or Require-Bundle
	 * manifest header like:
	 * 
	 * <pre>
	 *     Import-Package: org.osgi.framework; resolution:=&quot;manditory&quot;
	 *     Require-Bundle: com.acme.module.test; resolution:=&quot;manditory&quot;
	 * </pre>
	 * 
	 * @see #RESOLUTION_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	RESOLUTION_MANDATORY					= "mandatory";

	/**
	 * Manifest header directive value identifying an optional resolution type.
	 * An optional resolution type indicates that the import or require bundle
	 * is optional and the bundle may be resolved without the import or require
	 * bundle being resolved. If the import or require bundle is not resolved
	 * when the bundle is resolved, the import or require bundle may not be
	 * resolved before the bundle is refreshed.
	 * 
	 * <p>
	 * The directive value is encoded in the Import-Package or Require-Bundle
	 * manifest header like:
	 * 
	 * <pre>
	 *     Import-Package: org.osgi.framework; resolution:=&quot;optional&quot;
	 *     Require-Bundle: com.acme.module.test; resolution:=&quot;optional&quot;
	 * </pre>
	 * 
	 * @see #RESOLUTION_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	RESOLUTION_OPTIONAL						= "optional";

	/**
	 * Manifest header directive identifying a list of packages that an exported
	 * package uses.
	 * 
	 * <p>
	 * The directive value is encoded in the Export-Package manifest header
	 * like:
	 * 
	 * <pre>
	 *     Export-Package: org.osgi.util.tracker; uses:=&quot;org.osgi.framework&quot;
	 * </pre>
	 * 
	 * @see #EXPORT_PACKAGE
	 * @since 1.3
	 */
	public final static String	USES_DIRECTIVE							= "uses";

	/**
	 * Manifest header directive identifying a list of classes to include in the
	 * exported package.
	 * 
	 * <p>
	 * This directive is used by the Export-Package manifest header to identify
	 * a list of classes of the specified package which must be allowed to be
	 * exported. The directive value is encoded in the Export-Package manifest
	 * header like:
	 * 
	 * <pre>
	 *     Export-Package: org.osgi.framework; include:=&quot;MyClass*&quot;
	 * </pre>
	 * 
	 * <p>
	 * This directive is also used by the Bundle-ActivationPolicy manifest
	 * header to identify the packages from which class loads will trigger lazy
	 * activation. The directive value is encoded in the Bundle-ActivationPolicy
	 * manifest header like:
	 * 
	 * <pre>
	 *     Bundle-ActivationPolicy: lazy; include:=&quot;org.osgi.framework&quot;
	 * </pre>
	 * 
	 * @see #EXPORT_PACKAGE
	 * @see #BUNDLE_ACTIVATIONPOLICY
	 * @since 1.3
	 */
	public final static String	INCLUDE_DIRECTIVE						= "include";

	/**
	 * Manifest header directive identifying a list of classes to exclude in the
	 * exported package..
	 * <p>
	 * This directive is used by the Export-Package manifest header to identify
	 * a list of classes of the specified package which must not be allowed to
	 * be exported. The directive value is encoded in the Export-Package
	 * manifest header like:
	 * 
	 * <pre>
	 *     Export-Package: org.osgi.framework; exclude:=&quot;*Impl&quot;
	 * </pre>
	 * 
	 * <p>
	 * This directive is also used by the Bundle-ActivationPolicy manifest
	 * header to identify the packages from which class loads will not trigger
	 * lazy activation. The directive value is encoded in the
	 * Bundle-ActivationPolicy manifest header like:
	 * 
	 * <pre>
	 *     Bundle-ActivationPolicy: lazy; exclude:=&quot;org.osgi.framework&quot;
	 * </pre>
	 * 
	 * @see #EXPORT_PACKAGE
	 * @see #BUNDLE_ACTIVATIONPOLICY
	 * @since 1.3
	 */
	public final static String	EXCLUDE_DIRECTIVE						= "exclude";

	/**
	 * Manifest header directive identifying names of matching attributes which
	 * must be specified by matching Import-Package statements in the
	 * Export-Package manifest header.
	 * 
	 * <p>
	 * The directive value is encoded in the Export-Package manifest header
	 * like:
	 * 
	 * <pre>
	 *     Export-Package: org.osgi.framework; mandatory:=&quot;bundle-symbolic-name&quot;
	 * </pre>
	 * 
	 * @see #EXPORT_PACKAGE
	 * @since 1.3
	 */
	public final static String	MANDATORY_DIRECTIVE						= "mandatory";

	/**
	 * Manifest header directive identifying the visibility of a required bundle
	 * in the Require-Bundle manifest header. The default value is
	 * {@link #VISIBILITY_PRIVATE private}.
	 * 
	 * <p>
	 * The directive value is encoded in the Require-Bundle manifest header
	 * like:
	 * 
	 * <pre>
	 *     Require-Bundle: com.acme.module.test; visibility:=&quot;reexport&quot;
	 * </pre>
	 * 
	 * @see #REQUIRE_BUNDLE
	 * @see #VISIBILITY_PRIVATE
	 * @see #VISIBILITY_REEXPORT
	 * @since 1.3
	 */
	public final static String	VISIBILITY_DIRECTIVE					= "visibility";

	/**
	 * Manifest header directive value identifying a private visibility type. A
	 * private visibility type indicates that any packages that are exported by
	 * the required bundle are not made visible on the export signature of the
	 * requiring bundle.
	 * 
	 * <p>
	 * The directive value is encoded in the Require-Bundle manifest header
	 * like:
	 * 
	 * <pre>
	 *     Require-Bundle: com.acme.module.test; visibility:=&quot;private&quot;
	 * </pre>
	 * 
	 * @see #VISIBILITY_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	VISIBILITY_PRIVATE						= "private";

	/**
	 * Manifest header directive value identifying a reexport visibility type. A
	 * reexport visibility type indicates any packages that are exported by the
	 * required bundle are re-exported by the requiring bundle. Any arbitrary
	 * arbitrary matching attributes with which they were exported by the
	 * required bundle are deleted.
	 * 
	 * <p>
	 * The directive value is encoded in the Require-Bundle manifest header
	 * like:
	 * 
	 * <pre>
	 *     Require-Bundle: com.acme.module.test; visibility:=&quot;reexport&quot;
	 * </pre>
	 * 
	 * @see #VISIBILITY_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	VISIBILITY_REEXPORT						= "reexport";

	/**
	 * Manifest header directive identifying the type of the extension fragment.
	 * 
	 * <p>
	 * The directive value is encoded in the Fragment-Host manifest header like:
	 * 
	 * <pre>
	 *     Fragment-Host: system.bundle; extension:=&quot;framework&quot;
	 * </pre>
	 * 
	 * @see #FRAGMENT_HOST
	 * @see #EXTENSION_FRAMEWORK
	 * @see #EXTENSION_BOOTCLASSPATH
	 * @since 1.3
	 */
	public final static String	EXTENSION_DIRECTIVE						= "extension";

	/**
	 * Manifest header directive value identifying the type of extension
	 * fragment. An extension fragment type of framework indicates that the
	 * extension fragment is to be loaded by the framework's class loader.
	 * 
	 * <p>
	 * The directive value is encoded in the Fragment-Host manifest header like:
	 * 
	 * <pre>
	 *     Fragment-Host: system.bundle; extension:=&quot;framework&quot;
	 * </pre>
	 * 
	 * @see #EXTENSION_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	EXTENSION_FRAMEWORK						= "framework";

	/**
	 * Manifest header directive value identifying the type of extension
	 * fragment. An extension fragment type of bootclasspath indicates that the
	 * extension fragment is to be loaded by the boot class loader.
	 * 
	 * <p>
	 * The directive value is encoded in the Fragment-Host manifest header like:
	 * 
	 * <pre>
	 *     Fragment-Host: system.bundle; extension:=&quot;bootclasspath&quot;
	 * </pre>
	 * 
	 * @see #EXTENSION_DIRECTIVE
	 * @since 1.3
	 */
	public final static String	EXTENSION_BOOTCLASSPATH					= "bootclasspath";

	/**
	 * Manifest header identifying the bundle's activation policy.
	 * <p>
	 * The attribute value may be retrieved from the <code>Dictionary</code>
	 * object returned by the <code>Bundle.getHeaders</code> method.
	 * 
	 * @since 1.4
	 * @see #ACTIVATION_LAZY
	 * @see #INCLUDE_DIRECTIVE
	 * @see #EXCLUDE_DIRECTIVE
	 */
	public final static String	BUNDLE_ACTIVATIONPOLICY					= "Bundle-ActivationPolicy";

	/**
	 * Bundle activation policy declaring the bundle must be activated when the
	 * first class load is made from the bundle.
	 * <p>
	 * A bundle with the lazy activation policy that is started with the
	 * {@link Bundle#START_ACTIVATION_POLICY START_ACTIVATION_POLICY} option
	 * will wait in the {@link Bundle#STARTING STARTING} state until the first
	 * class load from the bundle occurs. The bundle will then be activated
	 * before the class is returned to the requester.
	 * <p>
	 * The activation policy value is specified as in the
	 * Bundle-ActivationPolicy manifest header like:
	 * 
	 * <pre>
	 *       Bundle-ActivationPolicy: lazy
	 * </pre>
	 * 
	 * @see #BUNDLE_ACTIVATIONPOLICY
	 * @see Bundle#start(int)
	 * @see Bundle#START_ACTIVATION_POLICY
	 * @since 1.4
	 */
	public final static String	ACTIVATION_LAZY							= "lazy";

	/**
	 * Framework environment property identifying the Framework version.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 */
	public static final String	FRAMEWORK_VERSION						= "org.osgi.framework.version";

	/**
	 * Framework environment property identifying the Framework implementation
	 * vendor.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 */
	public static final String	FRAMEWORK_VENDOR						= "org.osgi.framework.vendor";

	/**
	 * Framework environment property identifying the Framework implementation
	 * language (see ISO 639 for possible values).
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 */
	public static final String	FRAMEWORK_LANGUAGE						= "org.osgi.framework.language";

	/**
	 * Framework environment property identifying the Framework host-computer's
	 * operating system.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 */
	public static final String	FRAMEWORK_OS_NAME						= "org.osgi.framework.os.name";

	/**
	 * Framework environment property identifying the Framework host-computer's
	 * operating system version number.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 */
	public static final String	FRAMEWORK_OS_VERSION					= "org.osgi.framework.os.version";

	/**
	 * Framework environment property identifying the Framework host-computer's
	 * processor name.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 */
	public static final String	FRAMEWORK_PROCESSOR						= "org.osgi.framework.processor";

	/**
	 * Framework environment property identifying execution environments
	 * provided by the Framework.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @since 1.2
	 */
	public static final String	FRAMEWORK_EXECUTIONENVIRONMENT			= "org.osgi.framework.executionenvironment";

	/**
	 * Framework environment property identifying packages for which the
	 * Framework must delegate class loading to the parent class loader of the
	 * bundle.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @see #FRAMEWORK_BUNDLE_PARENT
	 * @since 1.3
	 */
	public static final String	FRAMEWORK_BOOTDELEGATION				= "org.osgi.framework.bootdelegation";

	/**
	 * Framework environment property identifying packages which the system
	 * bundle must export.
	 * 
	 * <p>
	 * If this property is not specified then the framework must calculate a
	 * reasonable default value for the current execution environment.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @since 1.3
	 */
	public static final String	FRAMEWORK_SYSTEMPACKAGES				= "org.osgi.framework.system.packages";

	/**
	 * Framework environment property identifying extra packages which the
	 * system bundle must export from the current execution environment.
	 * 
	 * <p>
	 * This property is useful for configuring extra system packages in addition
	 * to the system packages calculated by the framework.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @see #FRAMEWORK_SYSTEMPACKAGES
	 * @since 1.5
	 */
	public static final String	FRAMEWORK_SYSTEMPACKAGES_EXTRA			= "org.osgi.framework.system.packages.extra";

	/**
	 * Framework environment property identifying whether the Framework supports
	 * framework extension bundles.
	 * 
	 * <p>
	 * As of version 1.4, the value of this property must be <code>true</code>.
	 * The Framework must support framework extension bundles.
	 * 
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @since 1.3
	 */
	public static final String	SUPPORTS_FRAMEWORK_EXTENSION			= "org.osgi.supports.framework.extension";

	/**
	 * Framework environment property identifying whether the Framework supports
	 * bootclasspath extension bundles.
	 * 
	 * <p>
	 * If the value of this property is <code>true</code>, then the Framework
	 * supports bootclasspath extension bundles. The default value is
	 * <code>false</code>.
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @since 1.3
	 */
	public static final String	SUPPORTS_BOOTCLASSPATH_EXTENSION		= "org.osgi.supports.bootclasspath.extension";

	/**
	 * Framework environment property identifying whether the Framework supports
	 * fragment bundles.
	 * 
	 * <p>
	 * As of version 1.4, the value of this property must be <code>true</code>.
	 * The Framework must support fragment bundles.
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @since 1.3
	 */
	public static final String	SUPPORTS_FRAMEWORK_FRAGMENT				= "org.osgi.supports.framework.fragment";

	/**
	 * Framework environment property identifying whether the Framework supports
	 * the {@link #REQUIRE_BUNDLE Require-Bundle} manifest header.
	 * 
	 * <p>
	 * As of version 1.4, the value of this property must be <code>true</code>.
	 * The Framework must support the <code>Require-Bundle</code> manifest
	 * header.
	 * <p>
	 * The value of this property may be retrieved by calling the
	 * <code>BundleContext.getProperty</code> method.
	 * 
	 * @since 1.3
	 */
	public static final String	SUPPORTS_FRAMEWORK_REQUIREBUNDLE		= "org.osgi.supports.framework.requirebundle";

	/**
	 * Specifies the type of security manager the framework must use. If not
	 * specified then the framework will not set the VM security manager.
	 * 
	 * @see #FRAMEWORK_SECURITY_OSGI
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_SECURITY						= "org.osgi.framework.security";

	/**
	 * Specifies that a security manager that supports all security aspects of
	 * the OSGi core specification including postponed conditions must be
	 * installed.
	 * 
	 * <p>
	 * If this value is specified and there is a security manager already
	 * installed, then a <code>SecurityException</code> must be thrown when the
	 * Framework is initialized.
	 * 
	 * @see #FRAMEWORK_SECURITY
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_SECURITY_OSGI					= "osgi";

	/**
	 * Specified the persistent storage area used by the framework. The value of
	 * this property must be a valid file path in the file system to a
	 * directory. If the specified directory does not exist then the framework
	 * will create the directory. If the specified path exists but is not a
	 * directory or if the framework fails to create the storage directory, then
	 * framework initialization must fail. The framework is free to use this
	 * directory as it sees fit. This area can not be shared with anything else.
	 * <p>
	 * If this property is not set, the framework should use a reasonable
	 * platform default for the persistent storage area.
	 * 
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_STORAGE						= "org.osgi.framework.storage";

	/**
	 * Specifies if and when the persistent storage area for the framework
	 * should be cleaned. If this property is not set, then the framework
	 * storage area must not be cleaned.
	 * 
	 * @see #FRAMEWORK_STORAGE_CLEAN_ONFIRSTINIT
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_STORAGE_CLEAN					= "org.osgi.framework.storage.clean";

	/**
	 * Specifies that the framework storage area must be cleaned before the
	 * framework is initialized for the first time. Subsequent inits, starts or
	 * updates of the framework will not result in cleaning the framework
	 * storage area.
	 * 
	 * @since 1.5
	 */
	public final static String  FRAMEWORK_STORAGE_CLEAN_ONFIRSTINIT			= "onFirstInit";

	/**
	 * Specifies a comma separated list of additional library file extensions
	 * that must be used when a bundle's class loader is searching for native
	 * libraries. If this property is not set, then only the library name
	 * returned by <code>System.mapLibraryName(String)</code> will be used to
	 * search. This is needed for certain operating systems which allow more
	 * than one extension for a library. For example, AIX allows library
	 * extensions of <code>.a</code> and <code>.so</code>, but
	 * <code>System.mapLibraryName(String)</code> will only return names with
	 * the <code>.a</code> extension.
	 * 
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_LIBRARY_EXTENSIONS			= "org.osgi.framework.library.extensions";

	/**
	 * Specifies an optional OS specific command to set file permissions on
	 * extracted native code. On some operating systems, it is required that
	 * native libraries be set to executable. This optional property allows you
	 * to specify the command. For example, on a UNIX style OS, this property
	 * could have the following value.
	 * 
	 * <pre>
	 * chmod +rx ${abspath}
	 * </pre>
	 * 
	 * The <code>${abspath}</code> is used by the framework to substitute the
	 * actual absolute file path.
	 * 
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_EXECPERMISSION				= "org.osgi.framework.command.execpermission";

	/**
	 * Specifies the trust repositories used by the framework. The value is a
	 * <code>java.io.File.pathSeparator</code> separated list of valid file
	 * paths to files that contain key stores of type <code>JKS</code>. The
	 * framework will use the key stores as trust repositories to authenticate
	 * certificates of trusted signers. The key stores are only used as
	 * read-only trust repositories to access public keys. No passwords are
	 * required to access the key stores' public keys.
	 * <p>
	 * Note that framework implementations are allowed to use other trust
	 * repositories in addition to the trust repositories specified by this
	 * property. How these other trust repositories are configured and populated
	 * is implementation specific.
	 * 
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_TRUST_REPOSITORIES			= "org.osgi.framework.trust.repositories";

	/**
	 * Specifies the current windowing system. The framework should provide a
	 * reasonable default if this is not set.
	 * 
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_WINDOWSYSTEM					= "org.osgi.framework.windowsystem";

	/**
	 * Specifies the beginning start level of the framework.
	 * 
	 * @see "Core Specification, section 8.2.3."
	 * @since 1.5
	 */
	public final static String	FRAMEWORK_BEGINNING_STARTLEVEL			= "org.osgi.framework.startlevel.beginning";

	/**
	 * Specifies the parent class loader type for all bundle class loaders.
	 * Default value is {@link #FRAMEWORK_BUNDLE_PARENT_BOOT boot}.
	 * 
	 * @see #FRAMEWORK_BUNDLE_PARENT_BOOT
	 * @see #FRAMEWORK_BUNDLE_PARENT_EXT
	 * @see #FRAMEWORK_BUNDLE_PARENT_APP
	 * @see #FRAMEWORK_BUNDLE_PARENT_FRAMEWORK
	 * @since 1.5
	 */
	public final static String FRAMEWORK_BUNDLE_PARENT 					= "org.osgi.framework.bundle.parent";

	/**
	 * Specifies to use of the boot class loader as the parent class loader for
	 * all bundle class loaders.
	 * 
	 * @since 1.5
	 * @see #FRAMEWORK_BUNDLE_PARENT
	 */
	public final static String	FRAMEWORK_BUNDLE_PARENT_BOOT			= "boot";

	/**
	 * Specifies to use the extension class loader as the parent class loader
	 * for all bundle class loaders.
	 * 
	 * @since 1.5
	 * @see #FRAMEWORK_BUNDLE_PARENT
	 */
	public final static String	FRAMEWORK_BUNDLE_PARENT_EXT				= "ext";

	/**
	 * Specifies to use the application class loader as the parent class loader
	 * for all bundle class loaders.  Depending on how the framework is 
	 * launched, this may refer to the same class loader as 
	 * {@link #FRAMEWORK_BUNDLE_PARENT_FRAMEWORK}.
	 * 
	 * @since 1.5
	 * @see #FRAMEWORK_BUNDLE_PARENT
	 */
	public final static String	FRAMEWORK_BUNDLE_PARENT_APP				= "app";

	/**
	 * Specifies to use the framework class loader as the parent class loader
	 * for all bundle class loaders. The framework class loader is the class
	 * loader used to load the framework implementation.  Depending on how the 
	 * framework is launched, this may refer to the same class loader as 
	 * {@link #FRAMEWORK_BUNDLE_PARENT_APP}.
	 * 
	 * @since 1.5
	 * @see #FRAMEWORK_BUNDLE_PARENT
	 */
	public final static String	FRAMEWORK_BUNDLE_PARENT_FRAMEWORK		= "framework";

	/*
	 * Service properties.
	 */
	
	/**
	 * Service property identifying all of the class names under which a service
	 * was registered in the Framework. The value of this property must be of
	 * type <code>String[]</code>.
	 * 
	 * <p>
	 * This property is set by the Framework when a service is registered.
	 */
	public static final String	OBJECTCLASS								= "objectClass";

	/**
	 * Service property identifying a service's registration number. The value
	 * of this property must be of type <code>Long</code>.
	 * 
	 * <p>
	 * The value of this property is assigned by the Framework when a service is
	 * registered. The Framework assigns a unique value that is larger than all
	 * previously assigned values since the Framework was started. These values
	 * are NOT persistent across restarts of the Framework.
	 */
	public static final String	SERVICE_ID								= "service.id";

	/**
	 * Service property identifying a service's persistent identifier.
	 * 
	 * <p>
	 * This property may be supplied in the <code>properties</code>
	 * <code>Dictionary</code> object passed to the
	 * <code>BundleContext.registerService</code> method. The value of this
	 * property must be of type <code>String</code>, <code>String[]</code>, or
	 * <code>Collection</code> of <code>String</code>.
	 * 
	 * <p>
	 * A service's persistent identifier uniquely identifies the service and
	 * persists across multiple Framework invocations.
	 * 
	 * <p>
	 * By convention, every bundle has its own unique namespace, starting with
	 * the bundle's identifier (see {@link Bundle#getBundleId}) and followed by
	 * a dot (.). A bundle may use this as the prefix of the persistent
	 * identifiers for the services it registers.
	 */
	public static final String	SERVICE_PID								= "service.pid";

	/**
	 * Service property identifying a service's ranking number.
	 * 
	 * <p>
	 * This property may be supplied in the <code>properties
	 * Dictionary</code> object passed to the
	 * <code>BundleContext.registerService</code> method. The value of this
	 * property must be of type <code>Integer</code>.
	 * 
	 * <p>
	 * The service ranking is used by the Framework to determine the <i>natural
	 * order</i> of services, see {@link ServiceReference#compareTo(Object)},
	 * and the <i>default</i> service to be returned from a call to the
	 * {@link BundleContext#getServiceReference} method.
	 * 
	 * <p>
	 * The default ranking is zero (0). A service with a ranking of
	 * <code>Integer.MAX_VALUE</code> is very likely to be returned as the
	 * default service, whereas a service with a ranking of
	 * <code>Integer.MIN_VALUE</code> is very unlikely to be returned.
	 * 
	 * <p>
	 * If the supplied property value is not of type <code>Integer</code>, it is
	 * deemed to have a ranking value of zero.
	 */
	public static final String	SERVICE_RANKING							= "service.ranking";

	/**
	 * Service property identifying a service's vendor.
	 * 
	 * <p>
	 * This property may be supplied in the properties <code>Dictionary</code>
	 * object passed to the <code>BundleContext.registerService</code> method.
	 */
	public static final String	SERVICE_VENDOR							= "service.vendor";

	/**
	 * Service property identifying a service's description.
	 * 
	 * <p>
	 * This property may be supplied in the properties <code>Dictionary</code>
	 * object passed to the <code>BundleContext.registerService</code> method.
	 */
	public static final String	SERVICE_DESCRIPTION						= "service.description"; 
}