org.eclipse.jdt.launching/launching/org/eclipse/jdt/launching/sourcelookup/PackageFragmentRootSourceLocation.java

package org.eclipse.jdt.launching.sourcelookup;

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp.  All rights reserved.
This file is made available under the terms of the Common Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v10.html
**********************************************************************/

import java.io.IOException;
import java.io.StringReader;
import java.text.MessageFormat;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.xerces.dom.DocumentImpl;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.PlatformObject;
import org.eclipse.core.runtime.Status;
import org.eclipse.jdt.core.IClassFile;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.IPackageFragmentRoot;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.internal.launching.JavaLaunchConfigurationUtils;
import org.eclipse.jdt.internal.launching.LaunchingMessages;
import org.eclipse.jdt.internal.launching.LaunchingPlugin;
import org.eclipse.jdt.launching.IJavaLaunchConfigurationConstants;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

/**
 * Locates source elements in a package fragment root. Returns
 * instances of <code>ICompilationUnit</code> and
 * </code>IClassFile</code>.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * @see IJavaSourceLocation
 * @since 2.1
 */
public class PackageFragmentRootSourceLocation extends PlatformObject implements IJavaSourceLocation {
	
	/**
	 * Associatd package framgment root 
	 */
	private IPackageFragmentRoot fRoot = null;
	
	/**
	 * Creates an empty source location.
	 */
	public PackageFragmentRootSourceLocation() {
	}	
	
	/**
	 * Creates a source location on the given package fragment root.
	 * 
	 * @param root package fragment root
	 */
	public PackageFragmentRootSourceLocation(IPackageFragmentRoot root) {
		setPackageFragmentRoot(root);
	}

	/**
	 * @see org.eclipse.jdt.launching.sourcelookup.IJavaSourceLocation#findSourceElement(String)
	 */
	public Object findSourceElement(String name) throws CoreException {
		if (name != null && getPackageFragmentRoot() != null) {
			IPackageFragment pkg = null;
			int index = name.lastIndexOf('.');
			if (index >= 0) {
				String fragment = name.substring(0, index);
				pkg = getPackageFragmentRoot().getPackageFragment(fragment);
				name = name.substring(index + 1);
			} else {
				pkg = getPackageFragmentRoot().getPackageFragment(""); //$NON-NLS-1$
			}
			if (pkg.exists()) {
				String typeName = null;
				index = name.indexOf('$');
				if (index >= 0) {
					typeName = name.substring(0, index);
				} else {
					typeName = name;
				}
				ICompilationUnit cu = pkg.getCompilationUnit(typeName + ".java"); //$NON-NLS-1$
				if (cu.exists()) {
					return cu;
				} 
				IClassFile cf = pkg.getClassFile(name + ".class"); //$NON-NLS-1$
				if (cf.exists()) {
					return cf;
				}
			}
		}
		return null;
	}

	/**
	 * @see org.eclipse.jdt.launching.sourcelookup.IJavaSourceLocation#getMemento()
	 */
	public String getMemento() throws CoreException {
		Document doc = new DocumentImpl();
		Element node = doc.createElement("javaPackageFragmentRootSourceLocation"); //$NON-NLS-1$
		doc.appendChild(node);
		String handle = ""; //$NON-NLS-1$
		if (getPackageFragmentRoot() != null) {
			handle = getPackageFragmentRoot().getHandleIdentifier();
		}
		node.setAttribute("handleId", handle); //$NON-NLS-1$
		
		try {
			return JavaLaunchConfigurationUtils.serializeDocument(doc);
		} catch (IOException e) {
			abort(MessageFormat.format(LaunchingMessages.getString("PackageFragmentRootSourceLocation.Unable_to_create_memento_for_package_fragment_root_source_location_{0}_5"), new String[] {getPackageFragmentRoot().getElementName()}), e); //$NON-NLS-1$
		}
		// execution will not reach here
		return null;
	}

	/**
	 * @see org.eclipse.jdt.launching.sourcelookup.IJavaSourceLocation#initializeFrom(String)
	 */
	public void initializeFrom(String memento) throws CoreException {
		Exception ex = null;
		try {
			Element root = null;
			DocumentBuilder parser =
				DocumentBuilderFactory.newInstance().newDocumentBuilder();
			StringReader reader = new StringReader(memento);
			InputSource source = new InputSource(reader);
			root = parser.parse(source).getDocumentElement();
												
			String handle = root.getAttribute("handleId"); //$NON-NLS-1$
			if (handle == null) {
				abort(LaunchingMessages.getString("PackageFragmentRootSourceLocation.Unable_to_initialize_source_location_-_missing_handle_identifier_for_package_fragment_root._6"), null); //$NON-NLS-1$
			} else {
				if (handle.length() == 0) {
					// empty package fragment
					setPackageFragmentRoot(null);
				} else {
					IJavaElement element = JavaCore.create(handle);
					if (element instanceof IPackageFragmentRoot) {
						setPackageFragmentRoot((IPackageFragmentRoot)element);
					} else {
						abort(LaunchingMessages.getString("PackageFragmentRootSourceLocation.Unable_to_initialize_source_location_-_package_fragment_root_does_not_exist._7"), null); //$NON-NLS-1$
					}
				}
			}
			return;
		} catch (ParserConfigurationException e) {
			ex = e;			
		} catch (SAXException e) {
			ex = e;
		} catch (IOException e) {
			ex = e;
		}
		abort(LaunchingMessages.getString("PackageFragmentRootSourceLocation.Exception_occurred_initializing_source_location._8"), ex); //$NON-NLS-1$
	}

	/**
	 * Returns the package fragment root associated with this
	 * source location, or <code>null</code> if none
	 * 
	 * @return the package fragment root associated with this
	 *  source location, or <code>null</code> if none
	 */
	public IPackageFragmentRoot getPackageFragmentRoot() {
		return fRoot;
	}

	/**
	 * Sets the package fragment root associated with this
	 * source location.
	 * 
	 * @param root package fragment root
	 */
	private void setPackageFragmentRoot(IPackageFragmentRoot root) {
		fRoot = root;
	}

	private boolean isEmpty(String string) {
		return string == null || string.length() == 0;
	}
	
	/**
	 * Throws an internal error exception
	 */
	private void abort(String message, Throwable e)	throws CoreException {
		IStatus s = new Status(IStatus.ERROR, LaunchingPlugin.getUniqueIdentifier(), IJavaLaunchConfigurationConstants.ERR_INTERNAL_ERROR, message, e);
		throw new CoreException(s);		
	}	
	
	/**
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals(Object object) {		
		if (object instanceof PackageFragmentRootSourceLocation) {
			 PackageFragmentRootSourceLocation root = (PackageFragmentRootSourceLocation)object;
			 if (getPackageFragmentRoot() == null) {
			 	return root.getPackageFragmentRoot() == null;
			 } else {
			 	return getPackageFragmentRoot().equals(root.getPackageFragmentRoot());
			 }
		}
		return false;
	}
	
	/**
	 * @see java.lang.Object#hashCode()
	 */
	public int hashCode() {
		if (getPackageFragmentRoot() == null) {
			return getClass().hashCode();
		} else {
			return getPackageFragmentRoot().hashCode();
		}
	}	

}