org.eclipse.virgo.ide.jdt.core/src/org/eclipse/virgo/ide/jdt/internal/core/classpath/ServerClasspathUtils.java

/*********************************************************************
 * Copyright (c) 2009, 2010 SpringSource, a division of VMware, Inc.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
**********************************************************************/

package org.eclipse.virgo.ide.jdt.internal.core.classpath;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.AssertionFailedException;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.internal.core.JavaProject;
import org.eclipse.jdt.internal.core.util.Util;
import org.eclipse.virgo.ide.jdt.core.JdtCorePlugin;
import org.eclipse.virgo.ide.runtime.core.ServerCorePlugin;
import org.eclipse.virgo.util.io.FileCopyUtils;

/**
 * Utility that persists and reads persisted {@link IClasspathEntry}s from a file called
 * <code>.settings/org.eclipse.virgo.ide.jdt.core.xml</code>.
 *
 * @author Christian Dupuis
 * @author Terry Hon
 * @since 1.0.1
 */
@SuppressWarnings("restriction")
class ServerClasspathUtils {

    /** The name of the persisted file within the .settings directory of a Eclipse project */
    private static final String CLASSPATH_FILE = "-" + JdtCorePlugin.PLUGIN_ID + ".xml";

    /**
     * Saves the contents of the given {@link StringBuilder} into the settings file
     */
    private static void saveFile(final IJavaProject project, final StringBuilder builder) {

        // Get the file from the project
        File file = new File(ServerCorePlugin.getDefault().getStateLocation().toFile(), project.getProject().getName() + CLASSPATH_FILE);
        FileOutputStream os = null;
        try {

            // Create a new file; override old file
            file.createNewFile();

            // Write the contents of the StringBuilder
            os = new FileOutputStream(file);
            os.write(builder.toString().getBytes("UTF-8"));
            os.flush();
        } catch (UnsupportedEncodingException e) {
            // can't happen as default UTF-8 is used
        } catch (IOException e) {
            JdtCorePlugin.log("Cannot save classpath entries to '" + file.getAbsolutePath() + "'", e);
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                }
            }
        }

    }

    /**
     * Persists the given {@link IClasspathEntry}s to a file
     */
    protected static void persistClasspathEntries(IJavaProject project, IClasspathEntry[] entries) {

        // Get the line separator from the platform configuration
        String lineSeparator = Util.getLineSeparator((String) null, project);

        // Create the xml string representation of the classpath entries
        StringBuilder builder = new StringBuilder("<classpath>").append(lineSeparator);
        if (project instanceof JavaProject) {
            JavaProject javaProject = (JavaProject) project;
            for (IClasspathEntry entry : entries) {
                builder.append(javaProject.encodeClasspathEntry(entry));
            }
        }
        builder.append("</classpath>").append(lineSeparator);

        // Save the contents to the settings file
        saveFile(project, builder);
    }

    /**
     * Reads the persisted classpath entries for the given <code>project</code> and returns the {@link IClasspathEntry}
     * s.
     * <p>
     * This method returns <code>null</code> to indicate that the file could not be read.
     */
    @SuppressWarnings({ "rawtypes" })
    protected static IClasspathEntry[] readPersistedClasspathEntries(IJavaProject project) {
        File file = new File(ServerCorePlugin.getDefault().getStateLocation().toFile(), project.getProject().getName() + CLASSPATH_FILE);

        String xmlClasspath = null;
        if (file.exists()) {
            try {
                byte[] bytes = FileCopyUtils.copyToByteArray(file);
                xmlClasspath = new String(bytes, org.eclipse.jdt.internal.compiler.util.Util.UTF_8);
            } catch (UnsupportedEncodingException e) {
                // can't happen as default UTF-8 is used
            } catch (IOException e) {
            }
        }

        if (xmlClasspath == null) {
            return null;
        }

        if (project instanceof JavaProject) {
            JavaProject javaProject = (JavaProject) project;
            try {
                Object decodedClassPath;

                try {
                    // needs reflection since return type of decodeClasspath has changed in Eclipse 3.6
                    Method method = javaProject.getClass().getMethod("decodeClasspath", String.class, Map.class);
                    decodedClassPath = method.invoke(javaProject, xmlClasspath, new HashMap());
                    if (decodedClassPath instanceof IClasspathEntry[][]) {
                        List<IClasspathEntry> decodedEntries = new ArrayList<IClasspathEntry>();
                        for (IClasspathEntry[] entry : (IClasspathEntry[][]) decodedClassPath) {
                            decodedEntries.addAll(Arrays.asList(entry));
                        }
                        return decodedEntries.toArray(new IClasspathEntry[decodedEntries.size()]);
                    } else if (decodedClassPath instanceof IClasspathEntry[]) {
                        return (IClasspathEntry[]) decodedClassPath;
                    }
                } catch (Exception e) {
                    JdtCorePlugin.log(e);
                }

            } catch (AssertionFailedException e) {
                JdtCorePlugin.log(e);
            }
        }

        return null;
    }
}