vminstallclasspath.java

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/**
 * Copyright (c) 2003-2007 Craig Setera
 * All Rights Reserved.
 * Licensed under the Eclipse Public License - v 1.0
 * For more information see http://www.eclipse.org/legal/epl-v10.html
 */
package eclipseme.core.model.impl;

import org.eclipse.jdt.launching.IVMInstall;
import org.eclipse.jdt.launching.JavaRuntime;
import org.eclipse.jdt.launching.LibraryLocation;

import eclipseme.core.importer.LibraryImporter;
import eclipseme.core.model.Classpath;
import eclipseme.core.model.ILibrary;
import eclipseme.core.persistence.IPersistenceProvider;
import eclipseme.core.persistence.PersistenceException;

/**
 * A special version of the Classpath class that is capable
 * of appending or prepending the primary {@link IVMInstall} classpath
 * libraries to this classpath dynamically.
 * <p />
 * Copyright (c) 2003-2007 Craig Setera<br>
 * All Rights Reserved.<br>
 * Licensed under the Eclipse Public License - v 1.0<p/>
 * <br>
 * $Revision$
 * <br>
 * $Date$
 * <br>
 * @author Craig Setera
 */
public class VMInstallClasspath extends Classpath {
	private boolean prependVMLibraries;
	private ILibrary[] entriesCache;
	
	/**
	 * Construct a new classpath with the libraries prepended
	 * or appended according to the provided boolean.
	 * 
	 * @param prependVMLibraries
	 */
	public VMInstallClasspath() {
		super();
	}

	/**
	 * @see eclipseme.core.model.Classpath#getEntries()
	 */
	public ILibrary[] getEntries() {
		if (entriesCache == null) {
			entriesCache = calculateEntries();
		}
		
		return entriesCache;
	}

	public boolean isPrependVMLibraries() {
		return prependVMLibraries;
	}

	/**
	 * @see eclipseme.core.model.Classpath#loadUsing(eclipseme.core.persistence.IPersistenceProvider)
	 */
	public void loadUsing(IPersistenceProvider persistenceProvider)
		throws PersistenceException 
	{
		super.loadUsing(persistenceProvider);
		persistenceProvider.loadBoolean("prependVMLibraries");
	}

	public void setPrependVMLibraries(boolean prependVMLibraries) {
		this.prependVMLibraries = prependVMLibraries;
	}
	
	/**
	 * @see eclipseme.core.model.Classpath#storeUsing(eclipseme.core.persistence.IPersistenceProvider)
	 */
	public void storeUsing(IPersistenceProvider persistenceProvider)
		throws PersistenceException 
	{
		super.storeUsing(persistenceProvider);
		persistenceProvider.storeBoolean("prependVMLibraries", prependVMLibraries);
	}

	/**
	 * Calculate the entries for this classpath based on the current 
	 * default VM installation.
	 * 
	 * @return
	 */
	private ILibrary[] calculateEntries() {
		ILibrary[] userLibs = super.getEntries();
		
		// Retrieve the libraries from the default VM Install
		LibraryLocation[] libraryLocations = 
			JavaRuntime.getLibraryLocations(JavaRuntime.getDefaultVMInstall());

		// Build our complete list of entries
		int vmLibIndex = prependVMLibraries ? 0 : userLibs.length;
		int userLibIndex = prependVMLibraries ? userLibs.length : 0;
		
		ILibrary[] allLibraries = new ILibrary[userLibs.length + libraryLocations.length];
		System.arraycopy(userLibs, 0, allLibraries, userLibIndex, userLibs.length);
		
		LibraryImporter importer = new LibraryImporter();
		for (int i = 0; i < libraryLocations.length; i++) {
			allLibraries[vmLibIndex++] = 
				importer.createLibraryFor(libraryLocations[i].getSystemLibraryPath().toFile());
		}
		
		return allLibraries;
	}
}