http://www.eclipse.org/jdt: Java Development Tools Core (Eclipse Foundation) 
Copyright (c) 2000, 2019 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation

/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.core;

import org.eclipse.core.runtime.IPath;


Interface of a classpath container.
A classpath container provides a way to indirectly reference a set of classpath entries through
a classpath entry of kind CPE_CONTAINER. Typically, a classpath container can
be used to describe a complex library composed of multiple JARs or projects, considering also
that containers can map to different set of entries on each project, in other words, several
projects can reference the same generic container path, but have each of them actually bound
to a different container object.


The set of entries associated with a classpath container may contain any of the following:

    

  •  library entries (CPE_LIBRARY) 
    • 

  •  project entries (CPE_PROJECT) 
    • 


In particular, a classpath container can neither reference further classpath containers or classpath variables.

 A library entry can reference other libraries through the Class-Path section of the JAR's MANIFEST.MF file. If the container wants such referenced entries to be part of the classpath, the container must explicitly add them to the array returned from getClasspathEntries(). 

Classpath container values are persisted locally to the workspace, but are not preserved from a
session to another. It is thus highly recommended to register a ClasspathContainerInitializer
for each referenced container (through the extension point "org.eclipse.jdt.core.ClasspathContainerInitializer").



See Also:
Since:2.0
/**
 * Interface of a classpath container.
 * A classpath container provides a way to indirectly reference a set of classpath entries through
 * a classpath entry of kind <code>CPE_CONTAINER</code>. Typically, a classpath container can
 * be used to describe a complex library composed of multiple JARs or projects, considering also
 * that containers can map to different set of entries on each project, in other words, several
 * projects can reference the same generic container path, but have each of them actually bound
 * to a different container object.
 * <p>
 * The set of entries associated with a classpath container may contain any of the following:
 * <ul>
 * <li> library entries (<code>CPE_LIBRARY</code>) </li>
 * <li> project entries (<code>CPE_PROJECT</code>) </li>
 * </ul>
 * In particular, a classpath container can neither reference further classpath containers or classpath variables.
 * <p> 
 * A library entry can reference other libraries through the Class-Path section of the JAR's MANIFEST.MF file. If the
 * container wants such referenced entries to be part of the classpath, the container must explicitly add them to the
 * array returned from {@link #getClasspathEntries()}.
 * <p>
 * Classpath container values are persisted locally to the workspace, but are not preserved from a
 * session to another. It is thus highly recommended to register a <code>ClasspathContainerInitializer</code>
 * for each referenced container (through the extension point "org.eclipse.jdt.core.ClasspathContainerInitializer").
 * <p>
 * @see IClasspathEntry
 * @since 2.0
 */

public interface IClasspathContainer {

	
Kind for a container mapping to an application library

/**
	 * Kind for a container mapping to an application library
	 */
	int K_APPLICATION = 1;

	
Kind for a container mapping to a system library

/**
	 * Kind for a container mapping to a system library
	 */
	int K_SYSTEM = 2;

	
Kind for a container mapping to a default system library, implicitly contributed by the runtime

/**
	 * Kind for a container mapping to a default system library, implicitly contributed by the runtime
	 */
	int K_DEFAULT_SYSTEM = 3;

	
Answers the set of classpath entries this container is mapping to.


The set of entries associated with a classpath container may contain any of the following:

    

  •  library entries (CPE_LIBRARY) 
    • 

  •  project entries (CPE_PROJECT) 
    • 


A classpath container can neither reference further classpath containers
or classpath variables.


A library entry can reference other libraries through the Class-Path section of the JAR's MANIFEST.MF file. If
the container wants such referenced entries to be part of the classpath, the container must explicitly add them
to the result.


This method is called by the Java model when it needs to resolve this
classpath container entry into a list of library and project entries.
The method is typically called exactly once for a given Java project,
and the resulting list of entries cached internally by the Java model.
This method must not be called by other clients.


There are a wide variety of conditions under which this method may be
invoked. To ensure that the implementation does not interfere with
correct functioning of the Java model, the implementation should use
only the following Java model APIs:




The effects of using other Java model APIs are unspecified.



See Also:
Returns:IClasspathEntry[] - the classpath entries this container represents
/**
	 * Answers the set of classpath entries this container is mapping to.
	 * <p>
	 * The set of entries associated with a classpath container may contain any of the following:
	 * <ul>
	 * <li> library entries (<code>CPE_LIBRARY</code>) </li>
	 * <li> project entries (<code>CPE_PROJECT</code>) </li>
	 * </ul>
	 * A classpath container can neither reference further classpath containers
	 * or classpath variables.
	 * <p>
	 * A library entry can reference other libraries through the Class-Path section of the JAR's MANIFEST.MF file. If
	 * the container wants such referenced entries to be part of the classpath, the container must explicitly add them
	 * to the result.
	 * <p>
	 * This method is called by the Java model when it needs to resolve this
	 * classpath container entry into a list of library and project entries.
	 * The method is typically called exactly once for a given Java project,
	 * and the resulting list of entries cached internally by the Java model.
	 * This method must not be called by other clients.
	 * <p>
	 * There are a wide variety of conditions under which this method may be
	 * invoked. To ensure that the implementation does not interfere with
	 * correct functioning of the Java model, the implementation should use
	 * only the following Java model APIs:
	 * <ul>
	 * <li>{@link JavaCore#newLibraryEntry(IPath, IPath, IPath, boolean)} and variants</li>
	 * <li>{@link JavaCore#newProjectEntry(IPath, boolean)} and variants</li>
	 * <li>{@link JavaCore#create(org.eclipse.core.resources.IWorkspaceRoot)}</li>
	 * <li>{@link JavaCore#create(org.eclipse.core.resources.IProject)}</li>
	 * <li>{@link JavaCore#getReferencedClasspathEntries(IClasspathEntry, IJavaProject)} with <code>null</code> as project</li>
	 * <li>{@link IJavaModel#getJavaProjects()}</li>
	 * <li>{@link IJavaProject#getRawClasspath()}</li>
	 * <li>{@link IJavaProject#readRawClasspath()}</li>
	 * <li>{@link IJavaProject#getOutputLocation()}</li>
	 * <li>{@link IJavaProject#readOutputLocation()}</li>
	 * <li>Java element operations marked as "handle-only"</li>
	 * </ul>
	 * <p>
	 * The effects of using other Java model APIs are unspecified.
	 * </p>
	 *
	 * @return IClasspathEntry[] - the classpath entries this container represents
	 * @see IClasspathEntry
	 */
    IClasspathEntry[] getClasspathEntries();

	
Answers a readable description of this container

Returns:String - a string description of the container
/**
	 * Answers a readable description of this container
	 *
	 * @return String - a string description of the container
	 */
    String getDescription();

	
Answers the kind of this container. Can be either:

    

  • K_APPLICATION if this container maps to an application library
    • 

  • K_SYSTEM if this container maps to a system library
    • 

  • K_DEFAULT_SYSTEM if this container maps to a default system library (library
	implicitly contributed by the runtime).
    • 


Typically, system containers should be placed first on a build path.

Returns:the kind of this container
/**
	 * Answers the kind of this container. Can be either:
	 * <ul>
	 * <li><code>K_APPLICATION</code> if this container maps to an application library</li>
	 * <li><code>K_SYSTEM</code> if this container maps to a system library</li>
	 * <li><code>K_DEFAULT_SYSTEM</code> if this container maps to a default system library (library
	 * 	implicitly contributed by the runtime).</li>
	 * </ul>
	 * Typically, system containers should be placed first on a build path.
	 * @return the kind of this container
	 */
    int getKind();

	
Answers the container path identifying this container.
A container path is formed by a first ID segment followed with extra segments, which
can be used as additional hints for resolving to this container.


The container ID is also used to identify aClasspathContainerInitializer
registered on the extension point "org.eclipse.jdt.core.classpathContainerInitializer", which can
be invoked if needing to resolve the container before it is explicitly set.



Returns:IPath - the container path that is associated with this container
/**
	 * Answers the container path identifying this container.
	 * A container path is formed by a first ID segment followed with extra segments, which
	 * can be used as additional hints for resolving to this container.
	 * <p>
	 * The container ID is also used to identify a<code>ClasspathContainerInitializer</code>
	 * registered on the extension point "org.eclipse.jdt.core.classpathContainerInitializer", which can
	 * be invoked if needing to resolve the container before it is explicitly set.
	 * <p>
	 * @return IPath - the container path that is associated with this container
	 */
    IPath getPath();
}