Copyright (c) 2000, 2013 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, 2013 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.internal.launching;


import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.jdt.core.ClasspathVariableInitializer;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.launching.IVMInstall;
import org.eclipse.jdt.launching.JavaRuntime;
import org.eclipse.jdt.launching.LibraryLocation;

public class JavaClasspathVariablesInitializer extends ClasspathVariableInitializer {

	
The monitor to use for progress reporting.
May be null
/**
	 * The monitor to use for progress reporting.
	 * May be null
	 */
	private IProgressMonitor fMonitor;

	
See Also:
initialize.initialize(String)/**
	 * @see ClasspathVariableInitializer#initialize(String)
	 */
	@Override
	public void initialize(String variable) {
		IVMInstall vmInstall= JavaRuntime.getDefaultVMInstall();
		if (vmInstall != null) {
			IPath newPath= null;
			LibraryLocation[] locations= JavaRuntime.getLibraryLocations(vmInstall);
			// look for rt.jar or classes.zip (both may exist, so do exhaustive search)
			LibraryLocation rtjar = null;
			LibraryLocation classeszip = null;
			for (int i = 0; i < locations.length; i++) {
				LibraryLocation location = locations[i];
				String name = location.getSystemLibraryPath().lastSegment();
				if (name.equalsIgnoreCase("rt.jar")) { //$NON-NLS-1$
					rtjar = location;
				} else if (name.equalsIgnoreCase("classes.zip")) { //$NON-NLS-1$
					classeszip = location;
				}
			}
			// rt.jar if present, then classes.zip, else the first library
			LibraryLocation systemLib = rtjar;
			if (systemLib == null) {
				systemLib = classeszip;
			}
			if (systemLib == null && locations.length > 0) {
				systemLib = locations[0];
			}
			if (systemLib != null) {
				if (variable.equals(JavaRuntime.JRELIB_VARIABLE)) {
					newPath= systemLib.getSystemLibraryPath();
				} else if (variable.equals(JavaRuntime.JRESRC_VARIABLE)) {
					newPath= systemLib.getSystemLibrarySourcePath();
				} else if (variable.equals(JavaRuntime.JRESRCROOT_VARIABLE)){
					newPath= systemLib.getPackageRootPath();
				}
				if (newPath == null) {
					return;
				}
				try {
					setJREVariable(newPath, variable);
				}
				catch (CoreException e) {
					LaunchingPlugin.log(e);
				}
			}
		}
	}

	private void setJREVariable(IPath newPath, String var) throws CoreException {
		JavaCore.setClasspathVariable(var, newPath, getMonitor());
	}

	protected IProgressMonitor getMonitor() {
		if (fMonitor == null) {
			return new NullProgressMonitor();
		}
		return fMonitor;
	}

}