org.eclipse.jdt.core.IJavaProject.java Source code

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/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     IBM Corporation - added getOption(String, boolean), getOptions(boolean) and setOptions(Map)
 *     IBM Corporation - deprecated getPackageFragmentRoots(IClasspathEntry) and
 *                               added findPackageFragmentRoots(IClasspathEntry)
 *     IBM Corporation - added isOnClasspath(IResource)
 *     IBM Corporation - added setOption(String, String)
 *     IBM Corporation - added forceClasspathReload(IProgressMonitor)
 *******************************************************************************/
package org.eclipse.jdt.core;

import java.util.Map;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IPath;

import org.eclipse.jdt.core.dom.IAnnotationBinding;
import org.eclipse.jdt.core.dom.IMethodBinding;
import org.eclipse.jdt.core.dom.IPackageBinding;
import org.eclipse.jdt.core.dom.ITypeBinding;
import org.eclipse.jdt.core.dom.IVariableBinding;
import org.eclipse.jdt.core.eval.IEvaluationContext;

/**
 * A Java project represents a view of a project resource in terms of Java
 * elements such as package fragments, types, methods and fields.
 * A project may contain several package roots, which contain package fragments.
 * A package root corresponds to an underlying folder or JAR.
 * <p>
 * Each Java project has a classpath, defining which folders contain source code and
 * where required libraries are located. Each Java project also has an output location,
 * defining where the builder writes <code>.class</code> files. A project that
 * references packages in another project can access the packages by including
 * the required project in a classpath entry. The Java model will present the
 * source elements in the required project; when building, the compiler will use
 * the corresponding generated class files from the required project's output
 * location(s)). The classpath format is a sequence of classpath entries
 * describing the location and contents of package fragment roots.
 * </p>
 * Java project elements need to be opened before they can be navigated or manipulated.
 * The children of a Java project are the package fragment roots that are
 * defined by the classpath and contained in this project (in other words, it
 * does not include package fragment roots for other projects). The children
 * (i.e. the package fragment roots) appear in the order they are defined by 
 * the classpath.
 * </p>
 * <p>
 * An instance of one of these handles can be created via
 * <code>JavaCore.create(project)</code>.
 * </p>
 *
 * @see JavaCore#create(org.eclipse.core.resources.IProject)
 * @see IClasspathEntry
 * @noimplement This interface is not intended to be implemented by clients.
 */
public interface IJavaProject extends IParent, IJavaElement, IOpenable {

    /**
     * Path of the file containing the project's classpath relative to the project's root.
     * 
     * <p>The file is a child of the project folder.</p>
     * <p>The format of this file is unspecified and it is not meant to be modified.
     * Its contents is modified by using the <code>IJavaProject#setRawClasspath(..)</code> methods.</p>
     * 
     * @see #setRawClasspath(IClasspathEntry[], IProgressMonitor)
     * @see #setRawClasspath(IClasspathEntry[], boolean, IProgressMonitor)
     * @see #setRawClasspath(IClasspathEntry[], IPath, IProgressMonitor)
     * @see #setRawClasspath(IClasspathEntry[], IClasspathEntry[], IPath, IProgressMonitor)
     * @see #setRawClasspath(IClasspathEntry[], IPath, boolean, IProgressMonitor)
     * @since 3.7
     */
    String CLASSPATH_FILE_NAME = ".classpath"; //$NON-NLS-1$

    /**
     * Decodes the classpath entry that has been encoded in the given string
     * in the context of this project.
     * Returns null if the encoded entry is malformed.
     *
     * @param encodedEntry the encoded classpath entry
     * @return the decoded classpath entry, or <code>null</code> if unable to decode it
     * @since 3.2
     */
    IClasspathEntry decodeClasspathEntry(String encodedEntry);

    /**
     * Encodes the given classpath entry into a string in the context of this project.
     *
     * @param classpathEntry the classpath entry to encode
     * @return the encoded classpath entry
     * @since 3.2
     */
    String encodeClasspathEntry(IClasspathEntry classpathEntry);

    /**
     * Returns the <code>IJavaElement</code> corresponding to the given
     * classpath-relative path, or <code>null</code> if no such
     * <code>IJavaElement</code> is found. The result is one of an
     * <code>ICompilationUnit</code>, <code>IClassFile</code>, or
     * <code>IPackageFragment</code>.
     * <p>
     * When looking for a package fragment, there might be several potential
     * matches; only one of them is returned.
     *
     * <p>For example, the path "java/lang/Object.java", would result in the
     * <code>ICompilationUnit</code> or <code>IClassFile</code> corresponding to
     * "java.lang.Object". The path "java/lang" would result in the
     * <code>IPackageFragment</code> for "java.lang".
     * @param path the given classpath-relative path
     * @exception JavaModelException if the given path is <code>null</code>
     *  or absolute
     * @return the <code>IJavaElement</code> corresponding to the given
     * classpath-relative path, or <code>null</code> if no such
     * <code>IJavaElement</code> is found
     */
    IJavaElement findElement(IPath path) throws JavaModelException;

    /**
     * Returns the <code>IJavaElement</code> corresponding to the given
     * classpath-relative path, or <code>null</code> if no such
     * <code>IJavaElement</code> is found. The result is one of an
     * <code>ICompilationUnit</code>, <code>IClassFile</code>, or
     * <code>IPackageFragment</code>. If it is an <code>ICompilationUnit</code>,
     * its owner is the given owner.
     * <p>
     * When looking for a package fragment, there might be several potential
     * matches; only one of them is returned.
     *
     * <p>For example, the path "java/lang/Object.java", would result in the
     * <code>ICompilationUnit</code> or <code>IClassFile</code> corresponding to
     * "java.lang.Object". The path "java/lang" would result in the
     * <code>IPackageFragment</code> for "java.lang".
     * @param path the given classpath-relative path
     * @param owner the owner of the returned compilation unit, ignored if it is
     *   not a compilation unit.
     * @exception JavaModelException if the given path is <code>null</code>
     *  or absolute
     * @return the <code>IJavaElement</code> corresponding to the given
     * classpath-relative path, or <code>null</code> if no such
     * <code>IJavaElement</code> is found
     * @since 3.0
     */
    IJavaElement findElement(IPath path, WorkingCopyOwner owner) throws JavaModelException;

    /**
     * Finds the Java element corresponding to the given binding key if any,
     * else returns <code>null</code>. Elements are looked up using this
     * project's classpath. The first element corresponding to
     * the given key on this project's classpath is returned.
     * <p>Possible elements are:
     * <ul>
     * <li>{@link IPackageFragment} for a binding key from an
     *       {@link IPackageBinding}</li>
     * <li>{@link IType} for a binding key from an {@link ITypeBinding}</li>
     * <li>{@link IMethod} for a binding key from an {@link IMethodBinding}</li>
     * <li>{@link IField} for a binding key from an {@link IVariableBinding}
     *       representing a {@link IVariableBinding#isField() field}</li>
     * <li>{@link ITypeParameter} for a binding key from an {@link ITypeBinding}
     *       representing a {@link ITypeBinding#isTypeVariable() type
     *       variable}</li>
     * <li>{@link IAnnotation} for a binding key from an
     *       {@link IAnnotationBinding}</li>
     * </ul></p>
     * <p>Note: if two methods correspond to the binding key because their
     * parameter types' simple names are the same, then the first one is returned.
     * For example, if a class defines two methods <code>foo(p1.Y, String)</code>
     * and <code>foo(p2.Y, String)</code>, in both cases the parameter type's
     * simple names  are <code>{"Y", "String"}</code>. Thus
     * <code>foo(p1.Y, String)</code> is returned.</p>
     *
     * @param bindingKey the given binding key
     * @param owner the owner of the returned element's compilation unit,
     *       or <code>null</code> if the default working copy owner must be
     *       used
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the Java element corresponding to the given key,
     *       or <code>null</code> if no such Java element is found
     * @since 3.4
     */
    IJavaElement findElement(String bindingKey, WorkingCopyOwner owner) throws JavaModelException;

    /**
     * Returns the first existing package fragment on this project's classpath
     * whose path matches the given (absolute) path, or <code>null</code> if none
     * exist.
     * The path can be:
     *    - internal to the workbench: "/Project/src"
     *  - external to the workbench: "c:/jdk/classes.zip/java/lang"
     * @param path the given absolute path
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first existing package fragment on this project's classpath
     * whose path matches the given (absolute) path, or <code>null</code> if none
     * exist
     */
    IPackageFragment findPackageFragment(IPath path) throws JavaModelException;

    /**
     * Returns the existing package fragment root on this project's classpath
     * whose path matches the given (absolute) path, or <code>null</code> if
     * one does not exist.
     * The path can be:
     *   - internal to the workbench: "/Compiler/src"
     *   - external to the workbench: "c:/jdk/classes.zip"
     * @param path the given absolute path
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the existing package fragment root on this project's classpath
     * whose path matches the given (absolute) path, or <code>null</code> if
     * one does not exist
     */
    IPackageFragmentRoot findPackageFragmentRoot(IPath path) throws JavaModelException;

    /**
     * Returns the existing package fragment roots identified by the given entry.
     * A classpath entry within the current project identifies a single root.
     * <p>
     * If the classpath entry denotes a variable, it will be resolved and return
     * the roots of the target entry (empty if not resolvable).
     * <p>
     * If the classpath entry denotes a container, it will be resolved and return
     * the roots corresponding to the set of container entries (empty if not resolvable).
     * <p>
     * The result does not include package fragment roots in other projects
     * referenced on this project's classpath.
     * 
     * @param entry the given entry
     * @return the existing package fragment roots identified by the given entry
     * @see IClasspathContainer
     * @since 2.1
     */
    IPackageFragmentRoot[] findPackageFragmentRoots(IClasspathEntry entry);

    /**
     * Returns the first type (excluding secondary types) found following this project's
     * classpath with the given fully qualified name or <code>null</code> if none is found.
     * The fully qualified name is a dot-separated name. For example,
     * a class B defined as a member type of a class A in package x.y should have a
     * the fully qualified name "x.y.A.B".
     *
     * Note that in order to be found, a type name (or its top level enclosing
     * type name) must match its corresponding compilation unit name. As a
     * consequence, secondary types cannot be found using this functionality.
     * To find secondary types use {@link #findType(String, IProgressMonitor)} instead.
     *
     * @param fullyQualifiedName the given fully qualified name
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given fully qualified name or <code>null</code> if none is found
     * @see IType#getFullyQualifiedName(char)
     * @since 2.0
     */
    IType findType(String fullyQualifiedName) throws JavaModelException;

    /**
     * Same functionality as {@link #findType(String)} but also looks for secondary
     * types if the given name does not match a compilation unit name.
     *
     * @param fullyQualifiedName the given fully qualified name
     * @param progressMonitor the progress monitor to report progress to,
     *    or <code>null</code> if no progress monitor is provided
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given fully qualified name or <code>null</code> if none is found
     * @see IType#getFullyQualifiedName(char)
     * @since 3.2
     */
    IType findType(String fullyQualifiedName, IProgressMonitor progressMonitor) throws JavaModelException;

    /**
     * Returns the first type (excluding secondary types) found following this project's
     * classpath with the given fully qualified name or <code>null</code> if none is found.
     * The fully qualified name is a dot-separated name. For example,
     * a class B defined as a member type of a class A in package x.y should have a
     * the fully qualified name "x.y.A.B".
     * If the returned type is part of a compilation unit, its owner is the given
     * owner.
     *
     * Note that in order to be found, a type name (or its top level enclosing
     * type name) must match its corresponding compilation unit name. As a
     * consequence, secondary types cannot be found using this functionality.
     * To find secondary types use {@link #findType(String, WorkingCopyOwner, IProgressMonitor)}
     * instead.
     *
     * @param fullyQualifiedName the given fully qualified name
     * @param owner the owner of the returned type's compilation unit
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given fully qualified name or <code>null</code> if none is found
     * @see IType#getFullyQualifiedName(char)
     * @since 3.0
     */
    IType findType(String fullyQualifiedName, WorkingCopyOwner owner) throws JavaModelException;

    /**
     * Same functionality as {@link #findType(String, WorkingCopyOwner)}
     * but also looks for secondary types if the given name does not match
     * a compilation unit name.
     *
     * @param fullyQualifiedName the given fully qualified name
     * @param owner the owner of the returned type's compilation unit
     * @param progressMonitor the progress monitor to report progress to,
     *    or <code>null</code> if no progress monitor is provided
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given fully qualified name or <code>null</code> if none is found
     * @see IType#getFullyQualifiedName(char)
     * @since 3.2
     */
    IType findType(String fullyQualifiedName, WorkingCopyOwner owner, IProgressMonitor progressMonitor)
            throws JavaModelException;

    /**
     * Returns the first type (excluding secondary types) found following this
     * project's classpath with the given package name and type qualified name
     * or <code>null</code> if none is found.
     * The package name is a dot-separated name.
     * The type qualified name is also a dot-separated name. For example,
     * a class B defined as a member type of a class A should have the
     * type qualified name "A.B".
     *
     * Note that in order to be found, a type name (or its top level enclosing
     * type name) must match its corresponding compilation unit name. As a
     * consequence, secondary types cannot be found using this functionality.
     * To find secondary types use {@link #findType(String, String, IProgressMonitor)}
     * instead.
     *
     * @param packageName the given package name
     * @param typeQualifiedName the given type qualified name
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given package name and type qualified name
     * or <code>null</code> if none is found
     * @see IType#getTypeQualifiedName(char)
     * @since 2.0
     */
    IType findType(String packageName, String typeQualifiedName) throws JavaModelException;

    /**
     * Same functionality as {@link #findType(String, String)} but also looks for
     * secondary types if the given name does not match a compilation unit name.
     *
     * @param packageName the given package name
     * @param typeQualifiedName the given type qualified name
     * @param progressMonitor the progress monitor to report progress to,
     *    or <code>null</code> if no progress monitor is provided
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given fully qualified name or <code>null</code> if none is found
     * @see IType#getFullyQualifiedName(char)
     * @since 3.2
     */
    IType findType(String packageName, String typeQualifiedName, IProgressMonitor progressMonitor)
            throws JavaModelException;

    /**
     * Returns the first type (excluding secondary types) found following this
     * project's classpath with the given package name and type qualified name
     * or <code>null</code> if none is found.
     * The package name is a dot-separated name.
     * The type qualified name is also a dot-separated name. For example,
     * a class B defined as a member type of a class A should have the
     * type qualified name "A.B".
     * If the returned type is part of a compilation unit, its owner is the given
     * owner.
     *
     * Note that in order to be found, a type name (or its top level enclosing
     * type name) must match its corresponding compilation unit name. As a
     * consequence, secondary types cannot be found using this functionality.
     * To find secondary types use {@link #findType(String, String, WorkingCopyOwner, IProgressMonitor)}
     * instead.
     *
     * @param packageName the given package name
     * @param typeQualifiedName the given type qualified name
     * @param owner the owner of the returned type's compilation unit
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given package name and type qualified name
     * or <code>null</code> if none is found
     * @see IType#getTypeQualifiedName(char)
     * @since 3.0
     */
    IType findType(String packageName, String typeQualifiedName, WorkingCopyOwner owner) throws JavaModelException;

    /**
     * Same functionality as {@link #findType(String, String, WorkingCopyOwner)}
     * but also looks for secondary types if the given name does not match a compilation unit name.
     *
     * @param packageName the given package name
     * @param typeQualifiedName the given type qualified name
     * @param owner the owner of the returned type's compilation unit
     * @param progressMonitor the progress monitor to report progress to,
     *    or <code>null</code> if no progress monitor is provided
     * @exception JavaModelException if this project does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @return the first type found following this project's classpath
     * with the given fully qualified name or <code>null</code> if none is found
     * @see IType#getFullyQualifiedName(char)
     * @since 3.2
     */
    IType findType(String packageName, String typeQualifiedName, WorkingCopyOwner owner,
            IProgressMonitor progressMonitor) throws JavaModelException;

    /**
     * Returns all of the existing package fragment roots that exist
     * on the classpath, in the order they are defined by the classpath.
     *
     * @return all of the existing package fragment roots that exist
     * on the classpath
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     */
    IPackageFragmentRoot[] getAllPackageFragmentRoots() throws JavaModelException;

    /**
     * Returns an array of non-Java resources directly contained in this project.
     * It does not transitively answer non-Java resources contained in folders;
     * these would have to be explicitly iterated over.
     * <p>
     * Non-Java resources includes other files and folders located in the
     * project not accounted for by any of it source or binary package fragment
     * roots. If the project is a source folder itself, resources excluded from the
     * corresponding source classpath entry by one or more exclusion patterns
     * are considered non-Java resources and will appear in the result
     * (possibly in a folder)
     * </p>
     *
     * @return an array of non-Java resources (<code>IFile</code>s and/or
     *              <code>IFolder</code>s) directly contained in this project
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     */
    Object[] getNonJavaResources() throws JavaModelException;

    /**
     * Helper method for returning one option value only. Equivalent to <code>(String)this.getOptions(inheritJavaCoreOptions).get(optionName)</code>
     * Note that it may answer <code>null</code> if this option does not exist, or if there is no custom value for it.
     * <p>
     * For a complete description of the configurable options, see <code>JavaCore#getDefaultOptions</code>.
     * </p>
     *
     * @param optionName the name of an option
     * @param inheritJavaCoreOptions - boolean indicating whether JavaCore options should be inherited as well
     * @return the String value of a given option
     * @see JavaCore#getDefaultOptions()
     * @since 2.1
     */
    String getOption(String optionName, boolean inheritJavaCoreOptions);

    /**
     * Returns the table of the current custom options for this project. Projects remember their custom options,
     * in other words, only the options different from the the JavaCore global options for the workspace.
     * A boolean argument allows to directly merge the project options with global ones from <code>JavaCore</code>.
     * <p>
     * For a complete description of the configurable options, see <code>JavaCore#getDefaultOptions</code>.
     * </p>
     *
     * @param inheritJavaCoreOptions - boolean indicating whether JavaCore options should be inherited as well
     * @return table of current settings of all options
     *   (key type: <code>String</code>; value type: <code>String</code>)
     * @see JavaCore#getDefaultOptions()
     * @since 2.1
     */
    Map<String, String> getOptions(boolean inheritJavaCoreOptions);

    /**
     * Returns the default output location for this project as a workspace-
     * relative absolute path.
     * <p>
     * The default output location is where class files are ordinarily generated
     * (and resource files, copied). Each source classpath entry can also
     * specify an output location for the generated class files (and copied
     * resource files) corresponding to compilation units under that source
     * folder. This makes it possible to arrange generated class files for
     * different source folders in different output folders, and not
     * necessarily the default output folder. This means that the generated
     * class files for the project may end up scattered across several folders,
     * rather than all in the default output folder (which is more standard).
     * </p>
     *
     * @return the workspace-relative absolute path of the default output folder
     * @exception JavaModelException if this element does not exist
     * @see #setOutputLocation(org.eclipse.core.runtime.IPath, IProgressMonitor)
     * @see IClasspathEntry#getOutputLocation()
     */
    IPath getOutputLocation() throws JavaModelException;

    /**
     * Returns a package fragment root for an external library
     * (a ZIP archive - e.g. a <code>.jar</code>, a <code>.zip</code> file, etc. -
     * or - since 3.4 - a class folder) at the specified file system path.
     * This is a handle-only method.  The underlying <code>java.io.File</code>
     * may or may not exist. No resource is associated with this local library
     * package fragment root.
     *
     * @param externalLibraryPath the library's file system path
     * @return a package fragment root for the external library at the specified file system path
     */
    IPackageFragmentRoot getPackageFragmentRoot(String externalLibraryPath);

    /**
     * Returns a package fragment root for the given resource, which
     * must either be a folder representing the top of a package hierarchy,
     * or a ZIP archive (e.g. a <code>.jar</code>, a <code>.zip</code> file, etc.)
     * This is a handle-only method.  The underlying resource may or may not exist.
     *
     * @param resource the given resource
     * @return a package fragment root for the given resource, which
     * must either be a folder representing the top of a package hierarchy,
     * or a ZIP archive (e.g. a <code>.jar</code>, a <code>.zip</code> file, etc.)
     */
    IPackageFragmentRoot getPackageFragmentRoot(IResource resource);

    /**
     * Returns all of the  package fragment roots contained in this
     * project, identified on this project's resolved classpath. The result
     * does not include package fragment roots in other projects referenced
     * on this project's classpath. The package fragment roots appear in the 
     * order they are defined by the classpath.
     *
     * <p>NOTE: This is equivalent to <code>getChildren()</code>.
     *
     * @return all of the  package fragment roots contained in this
     * project, identified on this project's resolved classpath
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     */
    IPackageFragmentRoot[] getPackageFragmentRoots() throws JavaModelException;

    /**
     * Returns the existing package fragment roots identified by the given entry.
     * A classpath entry within the current project identifies a single root.
     * <p>
     * If the classpath entry denotes a variable, it will be resolved and return
     * the roots of the target entry (empty if not resolvable).
     * <p>
     * If the classpath entry denotes a container, it will be resolved and return
     * the roots corresponding to the set of container entries (empty if not resolvable).
     * <p>
     * The result does not include package fragment roots in other projects
     * referenced on this project's classpath.
     * 
     * @param entry the given entry
     * @return the existing package fragment roots identified by the given entry
     * @see IClasspathContainer
     * @deprecated Use {@link IJavaProject#findPackageFragmentRoots(IClasspathEntry)} instead
     */
    IPackageFragmentRoot[] getPackageFragmentRoots(IClasspathEntry entry);

    /**
     * Returns all package fragments in all package fragment roots contained
     * in this project. This is a convenience method.
     *
     * Note that the package fragment roots corresponds to the resolved
     * classpath of the project.
     *
     * @return all package fragments in all package fragment roots contained
     * in this project
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     */
    IPackageFragment[] getPackageFragments() throws JavaModelException;

    /**
     * Returns the <code>IProject</code> on which this <code>IJavaProject</code>
     * was created. This is handle-only method.
     *
     * @return the <code>IProject</code> on which this <code>IJavaProject</code>
     * was created
     */
    IProject getProject();

    /**
     * Returns the raw classpath for the project, as a list of classpath
     * entries. This corresponds to the exact set of entries which were assigned
     * using <code>setRawClasspath</code>, in particular such a classpath may
     * contain classpath variable and classpath container entries. Classpath
     * variable and classpath container entries can be resolved using the
     * helper method <code>getResolvedClasspath</code>; classpath variable
     * entries also can be resolved individually using
     * <code>JavaCore#getClasspathVariable</code>).
     * <p>
     * Both classpath containers and classpath variables provides a level of
     * indirection that can make the <code>.classpath</code> file stable across
     * workspaces.
     * As an example, classpath variables allow a classpath to no longer refer
     * directly to external JARs located in some user specific location.
     * The classpath can simply refer to some variables defining the proper
     * locations of these external JARs. Similarly, classpath containers
     * allows classpath entries to be computed dynamically by the plug-in that
     * defines that kind of classpath container.
     * </p>
     * <p>
     * Note that in case the project isn't yet opened, the classpath will
     * be read directly from the associated <tt>.classpath</tt> file.
     * </p>
     *
     * @return the raw classpath for the project, as a list of classpath entries
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @see IClasspathEntry
     */
    IClasspathEntry[] getRawClasspath() throws JavaModelException;

    /**
     * Returns the names of the projects that are directly required by this
     * project. A project is required if it is in its classpath.
     * <p>
     * The project names are returned in the order they appear on the classpath.
     *
     * @return the names of the projects that are directly required by this
     * project in classpath order
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     */
    String[] getRequiredProjectNames() throws JavaModelException;

    /**
     * This is a helper method returning the resolved classpath for the project
     * as a list of simple (non-variable, non-container) classpath entries.
     * All classpath variable and classpath container entries in the project's
     * raw classpath will be replaced by the simple classpath entries they
     * resolve to.
     * <p>
     * The resulting resolved classpath is accurate for the given point in time.
     * If the project's raw classpath is later modified, or if classpath
     * variables are changed, the resolved classpath can become out of date.
     * Because of this, hanging on resolved classpath is not recommended.
     * </p>
     * <p>
     * Note that if the resolution creates duplicate entries 
     * (i.e. {@link IClasspathEntry entries} which are {@link Object#equals(Object)}), 
     * only the first one is added to the resolved classpath.
     * </p>
     *
     * @param ignoreUnresolvedEntry indicates how to handle unresolvable
     * variables and containers; <code>true</code> indicates that missing
     * variables and unresolvable classpath containers should be silently
     * ignored, and that the resulting list should consist only of the
     * entries that could be successfully resolved; <code>false</code> indicates
     * that a <code>JavaModelException</code> should be thrown for the first
     * unresolved variable or container
     * @return the resolved classpath for the project as a list of simple
     * classpath entries, where all classpath variable and container entries
     * have been resolved and substituted with their final target entries
     * @exception JavaModelException in one of the corresponding situation:
     * <ul>
     *    <li>this element does not exist</li>
     *    <li>an exception occurs while accessing its corresponding resource</li>
     *    <li>a classpath variable or classpath container was not resolvable
     *    and <code>ignoreUnresolvedEntry</code> is <code>false</code>.</li>
     * </ul>
     * @see IClasspathEntry
     */
    IClasspathEntry[] getResolvedClasspath(boolean ignoreUnresolvedEntry) throws JavaModelException;

    /**
     * Returns whether this project has been built at least once and thus whether it has a build state.
     * @return true if this project has been built at least once, false otherwise
     */
    boolean hasBuildState();

    /**
     * Returns whether setting this project's classpath to the given classpath entries
     * would result in a cycle.
     *
     * If the set of entries contains some variables, those are resolved in order to determine
     * cycles.
     *
     * @param entries the given classpath entries
     * @return true if the given classpath entries would result in a cycle, false otherwise
     */
    boolean hasClasspathCycle(IClasspathEntry[] entries);

    /**
     * Returns whether the given element is on the classpath of this project,
     * that is, referenced from a classpath entry and not explicitly excluded
     * using an exclusion pattern.
     *
     * @param element the given element
     * @return <code>true</code> if the given element is on the classpath of
     * this project, <code>false</code> otherwise
     * @see IClasspathEntry#getInclusionPatterns()
     * @see IClasspathEntry#getExclusionPatterns()
     * @since 2.0
     */
    boolean isOnClasspath(IJavaElement element);

    /**
     * Returns whether the given resource is on the classpath of this project,
     * that is, referenced from a classpath entry and not explicitly excluded
     * using an exclusion pattern.
     *
     * @param resource the given resource
     * @return <code>true</code> if the given resource is on the classpath of
     * this project, <code>false</code> otherwise
     * @see IClasspathEntry#getInclusionPatterns()
     * @see IClasspathEntry#getExclusionPatterns()
     * @since 2.1
     */
    boolean isOnClasspath(IResource resource);

    /**
     * Creates a new evaluation context.
     * @return a new evaluation context.
     */
    IEvaluationContext newEvaluationContext();

    /**
     * Creates and returns a type hierarchy for all types in the given
     * region, considering subtypes within that region.
     *
     * @param monitor the given progress monitor
     * @param region the given region
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @exception IllegalArgumentException if region is <code>null</code>
     * @return a type hierarchy for all types in the given
     * region, considering subtypes within that region
     */
    ITypeHierarchy newTypeHierarchy(IRegion region, IProgressMonitor monitor) throws JavaModelException;

    /**
     * Creates and returns a type hierarchy for all types in the given
     * region, considering subtypes within that region and considering types in the
     * working copies with the given owner.
     * In other words, the owner's working copies will take
     * precedence over their original compilation units in the workspace.
     * <p>
     * Note that if a working copy is empty, it will be as if the original compilation
     * unit had been deleted.
     * <p>
     *
     * @param monitor the given progress monitor
     * @param region the given region
     * @param owner the owner of working copies that take precedence over their original compilation units
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     * @exception IllegalArgumentException if region is <code>null</code>
     * @return a type hierarchy for all types in the given
     * region, considering subtypes within that region
     * @since 3.0
     */
    ITypeHierarchy newTypeHierarchy(IRegion region, WorkingCopyOwner owner, IProgressMonitor monitor)
            throws JavaModelException;

    /**
     * Creates and returns a type hierarchy for the given type considering
     * subtypes in the specified region.
     *
     * @param type the given type
     * @param region the given region
     * @param monitor the given monitor
     *
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     *
     * @exception IllegalArgumentException if type or region is <code>null</code>
     * @return a type hierarchy for the given type considering
     * subtypes in the specified region
     */
    ITypeHierarchy newTypeHierarchy(IType type, IRegion region, IProgressMonitor monitor) throws JavaModelException;

    /**
     * Creates and returns a type hierarchy for the given type considering
     * subtypes in the specified region and considering types in the
     * working copies with the given owner.
     * In other words, the owner's working copies will take
     * precedence over their original compilation units in the workspace.
     * <p>
     * Note that if a working copy is empty, it will be as if the original compilation
     * unit had been deleted.
     * <p>
     *
     * @param type the given type
     * @param region the given region
     * @param monitor the given monitor
     * @param owner the owner of working copies that take precedence over their original compilation units
     *
     * @exception JavaModelException if this element does not exist or if an
     *      exception occurs while accessing its corresponding resource
     *
     * @exception IllegalArgumentException if type or region is <code>null</code>
     * @return a type hierarchy for the given type considering
     * subtypes in the specified region
     * @since 3.0
     */
    ITypeHierarchy newTypeHierarchy(IType type, IRegion region, WorkingCopyOwner owner, IProgressMonitor monitor)
            throws JavaModelException;

    /**
     * Returns the default output location for the project as defined by its <code>.classpath</code> file from disk, or <code>null</code>
     * if unable to read the file.
     * <p>
     * This output location may differ from the in-memory one returned by <code>getOutputLocation</code>, in case the
     * automatic reconciliation mechanism has not been performed yet. Usually, any change to the <code>.classpath</code> file
     * is automatically noticed and reconciled at the next resource change notification event.
     * However, if the file is modified within an operation, where this change needs to be taken into account before the
     * operation ends, then the output location from disk can be read using this method, and further assigned to the project
     * using <code>setRawClasspath(...)</code>.
     * <p>
     * The default output location is where class files are ordinarily generated
     * (and resource files, copied). Each source classpath entry can also
     * specify an output location for the generated class files (and copied
     * resource files) corresponding to compilation units under that source
     * folder. This makes it possible to arrange generated class files for
     * different source folders in different output folders, and not
     * necessarily the default output folder. This means that the generated
     * class files for the project may end up scattered across several folders,
     * rather than all in the default output folder (which is more standard).
     * <p>
     * In order to manually force a project classpath refresh, one can simply assign the project classpath using the result of this
     * method, as follows:
     * <code>proj.setRawClasspath(proj.readRawClasspath(), proj.readOutputLocation(), monitor)</code>
     * (note that the <code>readRawClasspath/readOutputLocation</code> methods could return <code>null</code>).
     * <p>
     * @return the workspace-relative absolute path of the default output folder
     * @see #getOutputLocation()
     * @since 3.0
     */
    IPath readOutputLocation();

    /**
     * Returns the raw classpath for the project as defined by its
     * <code>.classpath</code> file from disk, or <code>null</code>
     * if unable to read the file.
     * <p>
     * This classpath may differ from the in-memory classpath returned by
     * <code>getRawClasspath</code>, in case the automatic reconciliation
     * mechanism has not been performed yet. Usually, any change to the
     * <code>.classpath</code> file is automatically noticed and reconciled at
     * the next resource change notification event. However, if the file is
     * modified within an operation, where this change needs to be taken into
     * account before the operation ends, then the classpath from disk can be
     * read using this method, and further assigned to the project using
     * <code>setRawClasspath(...)</code>.
     * </p>
     * <p>
     * Classpath variable and classpath container entries can be resolved using
     * the helper method <code>getResolvedClasspath</code>; classpath variable
     * entries also can be resolved individually using
     * <code>JavaCore#getClasspathVariable</code>).
     * </p>
     * <p>
     * Note that no check is performed whether the project has the Java nature
     * set, allowing an existing <code>.classpath</code> file to be considered
     * independantly (unlike <code>getRawClasspath</code> which requires the
     * Java nature to be associated with the project).
     * </p>
     * <p>
     * In order to manually force a project classpath refresh, one can simply
     * assign the project classpath using the result of this method, as follows:
     * <code>proj.setRawClasspath(proj.readRawClasspath(), proj.readOutputLocation(), monitor)</code>
     * (note that the <code>readRawClasspath/readOutputLocation</code> methods
     * could return <code>null</code>).
     * </p>
     *
     * @return the raw classpath from disk for the project, as a list of
     * classpath entries
     * @see #getRawClasspath()
     * @see IClasspathEntry
     * @since 3.0
     */
    IClasspathEntry[] readRawClasspath();

    /**
     * Helper method for setting one option value only.
     *<p>
     * Equivalent to:
     * <pre>
     *    Map options = this.getOptions(false);
     *    map.put(optionName, optionValue);
     *    this.setOptions(map)
     *  </pre>
     * <p>
     * For a complete description of the configurable options, see <code>JavaCore#getDefaultOptions</code>.
     * </p>
     *
     * @param optionName the name of an option
     * @param optionValue the value of the option to set. If <code>null</code>, then the option
     *    is removed from project preferences.
     * @throws NullPointerException if <code>optionName</code> is <code>null</code>
     *    (see {@link org.osgi.service.prefs.Preferences#put(String, String)}).
     * @see JavaCore#getDefaultOptions()
     * @since 3.0
     */
    void setOption(String optionName, String optionValue);

    /**
     * Sets the project custom options. All and only the options explicitly included in the given table
     * are remembered; all previous option settings are forgotten, including ones not explicitly
     * mentioned.
     * <p>
     * For a complete description of the configurable options, see <code>JavaCore#getDefaultOptions</code>.
     * </p>
     *
     * @param newOptions the new options (key type: <code>String</code>; value type: <code>String</code>),
     *   or <code>null</code> to flush all custom options (clients will automatically get the global JavaCore options).
     * @see JavaCore#getDefaultOptions()
     * @since 2.1
     */
    void setOptions(Map<String, String> newOptions);

    /**
     * Sets the default output location of this project to the location
     * described by the given workspace-relative absolute path.
     * <p>
     * The default output location is where class files are ordinarily generated
     * (and resource files, copied). Each source classpath entries can also
     * specify an output location for the generated class files (and copied
     * resource files) corresponding to compilation units under that source
     * folder. This makes it possible to arrange that generated class files for
     * different source folders to end up in different output folders, and not
     * necessarily the default output folder. This means that the generated
     * class files for the project may end up scattered across several folders,
     * rather than all in the default output folder (which is more standard).
     * </p>
     *
     * @param path the workspace-relative absolute path of the default output
     * folder
     * @param monitor the progress monitor
     *
     * @exception JavaModelException if the classpath could not be set. Reasons include:
     * <ul>
     *  <li> This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     *  <li> The path refers to a location not contained in this project (<code>PATH_OUTSIDE_PROJECT</code>)
     *  <li> The path is not an absolute path (<code>RELATIVE_PATH</code>)
     *  <li> The path is nested inside a package fragment root of this project (<code>INVALID_PATH</code>)
     *  <li> The output location is being modified during resource change event notification (CORE_EXCEPTION)
     * </ul>
     * @see #getOutputLocation()
      * @see IClasspathEntry#getOutputLocation()
     */
    void setOutputLocation(IPath path, IProgressMonitor monitor) throws JavaModelException;

    /**
     * Sets both the classpath of this project and its default output
     * location at once. The classpath is defined using a list of classpath
     * entries. In particular such a classpath may contain classpath variable entries.
     * Classpath variable entries can be resolved individually ({@link JavaCore#getClasspathVariable(String)}),
     * or the full classpath can be resolved at once using the helper method {@link #getResolvedClasspath(boolean)}.
     * <p>
     * A classpath variable provides an indirection level for better sharing a classpath. As an example, it allows
     * a classpath to no longer refer directly to external JARs located in some user specific location. The classpath
     * can simply refer to some variables defining the proper locations of these external JARs.
     * </p><p>
     * If it is specified that this operation cannot modify resources, the .classpath file will not be written to disk
     * and no error marker will be generated. To synchronize the .classpath with the in-memory classpath,
     * one can use <code>setRawClasspath(readRawClasspath(), true, monitor)</code>.
     * </p><p>
     * Setting the classpath to <code>null</code> specifies a default classpath
     * (the project root). Setting the classpath to an empty array specifies an
     * empty classpath.
     * </p><p>
     * If a cycle is detected while setting this classpath (and if resources can be modified), an error marker will be added
     * to the project closing the cycle.
     * To avoid this problem, use {@link #hasClasspathCycle(IClasspathEntry[])}
     * before setting the classpath.
     * <p>
     * This operation acquires a lock on the workspace's root.
     *
     * @param entries a list of classpath entries
     * @param outputLocation the default output location
     * @param canModifyResources whether resources should be written to disk if needed
     * @param monitor the given progress monitor
     * @exception JavaModelException if the classpath could not be set. Reasons include:
     * <ul>
     * <li> This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     * <li> The classpath is being modified during resource change event notification (CORE_EXCEPTION)
     * <li> The classpath failed the validation check as defined by {@link JavaConventions#validateClasspath(IJavaProject, IClasspathEntry[], IPath)}
     * </ul>
     * @see IClasspathEntry
     * @since 3.2
     */
    void setRawClasspath(IClasspathEntry[] entries, IPath outputLocation, boolean canModifyResources,
            IProgressMonitor monitor) throws JavaModelException;

    /**
     * Sets the classpath of this project using a list of classpath entries. In particular such a classpath may contain
     * classpath variable entries. Classpath variable entries can be resolved individually ({@link JavaCore#getClasspathVariable(String)}),
     * or the full classpath can be resolved at once using the helper method {@link #getResolvedClasspath(boolean)}.
     * <p>
     * A classpath variable provides an indirection level for better sharing a classpath. As an example, it allows
     * a classpath to no longer refer directly to external JARs located in some user specific location. The classpath
     * can simply refer to some variables defining the proper locations of these external JARs.
     * </p><p>
     * If it is specified that this operation cannot modify resources, the .classpath file will not be written to disk
     * and no error marker will be generated. To synchronize the .classpath with the in-memory classpath,
     * one can use <code>setRawClasspath(readRawClasspath(), true, monitor)</code>.
     * </p><p>
     * Setting the classpath to <code>null</code> specifies a default classpath
     * (the project root). Setting the classpath to an empty array specifies an
     * empty classpath.
     * </p><p>
     * If a cycle is detected while setting this classpath (and if resources can be modified), an error marker will be added
     * to the project closing the cycle.
     * To avoid this problem, use {@link #hasClasspathCycle(IClasspathEntry[])}
     * before setting the classpath.
     * <p>
     * This operation acquires a lock on the workspace's root.
     *
     * @param entries a list of classpath entries
     * @param canModifyResources whether resources should be written to disk if needed
     * @param monitor the given progress monitor
     * @exception JavaModelException if the classpath could not be set. Reasons include:
     * <ul>
     * <li> This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     * <li> The classpath is being modified during resource change event notification (CORE_EXCEPTION)
     * <li> The classpath failed the validation check as defined by {@link JavaConventions#validateClasspath(IJavaProject, IClasspathEntry[], IPath)}
     * </ul>
     * @see IClasspathEntry
     * @since 3.2
     */
    void setRawClasspath(IClasspathEntry[] entries, boolean canModifyResources, IProgressMonitor monitor)
            throws JavaModelException;

    /**
     * Works similar to {@link #setRawClasspath(IClasspathEntry[], IPath, IProgressMonitor)} and 
     * additionally allows persisting the given array of referenced entries for this project.
     * The referenced entries and their attributes are stored in the .classpath file of this 
     * project. For details on referenced entries, see 
     * {@link JavaCore#getReferencedClasspathEntries(IClasspathEntry, IJavaProject)}
     * and {@link IClasspathEntry#getReferencingEntry()}.
     * <p>
     * Since the referenced entries are stored in the .classpath file, clients can store additional 
     * information that belong to these entries and retrieve them across sessions, though the referenced
     * entries themselves may not be present in the raw classpath. By passing a <code>null</code>
     * referencedEntries, clients can choose not to modify the already persisted referenced entries,
     * which is fully equivalent to {@link #setRawClasspath(IClasspathEntry[], IPath, IProgressMonitor)}.
     * If an empty array is passed as referencedEntries, the already persisted referenced entries, 
     * if any, will be cleared. 
     * </p> <p>
     * If there are duplicates of a referenced entry or if any of the <code>referencedEntries</code> 
     * is already present in the raw classpath(<code>entries</code>) those referenced entries will 
     * be excluded and not be persisted.
     *</p>
     * @param entries a list of classpath entries
     * @param referencedEntries the list of referenced classpath entries to be persisted
     * @param outputLocation the default output location
     * @param monitor the given progress monitor
     * @exception JavaModelException if the classpath could not be set. Reasons include:
     * <ul>
     * <li> This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     * <li> The classpath is being modified during resource change event notification (CORE_EXCEPTION)
     * <li> The classpath failed the validation check as defined by {@link JavaConventions#validateClasspath(IJavaProject, IClasspathEntry[], IPath)}
     * </ul>
     * @see IClasspathEntry
     * @see #getReferencedClasspathEntries()
     * @since 3.6
     */
    void setRawClasspath(IClasspathEntry[] entries, IClasspathEntry[] referencedEntries, IPath outputLocation,
            IProgressMonitor monitor) throws JavaModelException;

    /**
     * Returns the list of referenced classpath entries stored in the .classpath file of <code>this</code> 
     * java project. Clients can store the referenced classpath entries using 
     * {@link #setRawClasspath(IClasspathEntry[], IClasspathEntry[], IPath, IProgressMonitor)}
     * If the client has not stored any referenced entries for this project, an empty array is returned.
     *
     * @throws JavaModelException
     * @return an array of referenced classpath entries stored for this java project or an empty array if none
     *          stored earlier.
     * @since 3.6
     */
    IClasspathEntry[] getReferencedClasspathEntries() throws JavaModelException;

    /**
     * Sets the classpath of this project using a list of classpath entries. In particular such a classpath may contain
     * classpath variable entries. Classpath variable entries can be resolved individually ({@link JavaCore#getClasspathVariable(String)}),
     * or the full classpath can be resolved at once using the helper method {@link #getResolvedClasspath(boolean)}.
     * <p>
     * A classpath variable provides an indirection level for better sharing a classpath. As an example, it allows
     * a classpath to no longer refer directly to external JARs located in some user specific location. The classpath
     * can simply refer to some variables defining the proper locations of these external JARs.
     * <p>
     * Setting the classpath to <code>null</code> specifies a default classpath
     * (the project root). Setting the classpath to an empty array specifies an
     * empty classpath.
     * <p>
     * If a cycle is detected while setting this classpath, an error marker will be added
     * to the project closing the cycle.
     * To avoid this problem, use {@link #hasClasspathCycle(IClasspathEntry[])}
     * before setting the classpath.
     * <p>
     * This operation acquires a lock on the workspace's root.
     *
     * @param entries a list of classpath entries
     * @param monitor the given progress monitor
     * @exception JavaModelException if the classpath could not be set. Reasons include:
     * <ul>
     * <li> This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     * <li> The classpath is being modified during resource change event notification (CORE_EXCEPTION)
     * <li> The classpath failed the validation check as defined by {@link JavaConventions#validateClasspath(IJavaProject, IClasspathEntry[], IPath)}
     * </ul>
     * @see IClasspathEntry
     */
    void setRawClasspath(IClasspathEntry[] entries, IProgressMonitor monitor) throws JavaModelException;

    /**
     * Sets the both the classpath of this project and its default output
     * location at once. The classpath is defined using a list of classpath
     * entries. In particular, such a classpath may contain classpath variable
     * entries. Classpath variable entries can be resolved individually (see
     * ({@link JavaCore#getClasspathVariable(String)}), or the full classpath can be
     * resolved at once using the helper method
     * {@link #getResolvedClasspath(boolean)}.
     * <p>
     * A classpath variable provides an indirection level for better sharing a
     * classpath. As an example, it allows a classpath to no longer refer
     * directly to external JARs located in some user specific location. The
     * classpath can simply refer to some variables defining the proper
     * locations of these external JARs.
     * </p>
     * <p>
     * Setting the classpath to <code>null</code> specifies a default classpath
     * (the project root). Setting the classpath to an empty array specifies an
     * empty classpath.
     * </p>
     * <p>
     * If a cycle is detected while setting this classpath, an error marker will
     * be added to the project closing the cycle. To avoid this problem, use
     * {@link #hasClasspathCycle(IClasspathEntry[])} before setting
     * the classpath.
     * </p>
     * <p>
     * This operation acquires a lock on the workspace's root.
     * </p>
     *
     * @param entries a list of classpath entries
     * @param monitor the progress monitor
     * @param outputLocation the default output location
     * @exception JavaModelException if the classpath could not be set. Reasons
     * include:
     * <ul>
     * <li> This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     * <li> Two or more entries specify source roots with the same or overlapping paths (NAME_COLLISION)
     * <li> A entry of kind <code>CPE_PROJECT</code> refers to this project (INVALID_PATH)
     *  <li>This Java element does not exist (ELEMENT_DOES_NOT_EXIST)</li>
     *   <li>The output location path refers to a location not contained in this project (<code>PATH_OUTSIDE_PROJECT</code>)
     *   <li>The output location path is not an absolute path (<code>RELATIVE_PATH</code>)
     *  <li>The output location path is nested inside a package fragment root of this project (<code>INVALID_PATH</code>)
     * <li> The classpath is being modified during resource change event notification (CORE_EXCEPTION)
     * </ul>
     * @see IClasspathEntry
     * @since 2.0
     */
    void setRawClasspath(IClasspathEntry[] entries, IPath outputLocation, IProgressMonitor monitor)
            throws JavaModelException;
}