com.google.cloud.tools.eclipse.appengine.compat.GpeMigrator.java Source code

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Here is the source code for com.google.cloud.tools.eclipse.appengine.compat.GpeMigrator.java

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/*
 * Copyright 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.cloud.tools.eclipse.appengine.compat;

import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.xml.transform.TransformerException;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.SubMonitor;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.wst.common.project.facet.core.IFacetedProject;

import com.google.cloud.tools.eclipse.util.NatureUtils;
import com.google.cloud.tools.eclipse.util.Xslt;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;

public class GpeMigrator {

    private static final Logger logger = Logger.getLogger(GpeMigrator.class.getName());

    private static final ImmutableList<String> GPE_CLASSPATH_ENTRIES_PATH = ImmutableList.of(
            "org.eclipse.jst.server.core.container/com.google.appengine.server.runtimeTarget/Google App Engine",
            "com.google.appengine.eclipse.core.GAE_CONTAINER",
            "com.google.appengine.eclipse.wtp.GAE_WTP_CONTAINER");

    private static final String GPE_GAE_NATURE_ID = "com.google.appengine.eclipse.core.gaeNature";

    private static final String WTP_METADATA_XSLT = "/xslt/wtpMetadata.xsl";

    // FacetedProject.METADATA_FILE = ".settings/" + FacetCorePlugin.PLUGIN_ID + ".xml";
    private static final String FACETS_METADATA_FILE = ".settings/org.eclipse.wst.common.project.facet.core.xml";

    /**
     * Removes various GPE-related remnants: classpath entries, nature, runtime, and facets. Any
     * error during operation is logged but ignored.
     */
    public static void removeObsoleteGpeRemnants(final IFacetedProject facetedProject, IProgressMonitor monitor)
            throws CoreException {
        SubMonitor subMonitor = SubMonitor.convert(monitor, 40);
        IProject project = facetedProject.getProject();

        removeGpeClasspathEntries(project);
        subMonitor.worked(10);

        removeGpeNature(project);
        subMonitor.worked(10);

        removeGpeRuntimeAndFacets(facetedProject);
        subMonitor.worked(20);
    }

    @VisibleForTesting
    static void removeGpeClasspathEntries(IProject project) {
        try {
            IJavaProject javaProject = JavaCore.create(project);
            List<IClasspathEntry> newEntries = new ArrayList<>();
            for (IClasspathEntry entry : javaProject.getRawClasspath()) {
                String path = entry.getPath().toString(); // note: '/' is a path separator.
                if (!GPE_CLASSPATH_ENTRIES_PATH.contains(path)) {
                    newEntries.add(entry);
                }
            }

            IClasspathEntry[] rawEntries = newEntries.toArray(new IClasspathEntry[0]);
            javaProject.setRawClasspath(rawEntries, new NullProgressMonitor());
            javaProject.save(new NullProgressMonitor(), true);

        } catch (JavaModelException ex) {
            logger.log(Level.WARNING, "Failed to remove GPE classpath entries.", ex);
        }
    }

    @VisibleForTesting
    static void removeGpeNature(IProject project) {
        try {
            NatureUtils.removeNature(project, GPE_GAE_NATURE_ID);
        } catch (CoreException ex) {
            logger.log(Level.WARNING, "Failed to remove GPE nature.", ex);
        }
    }

    @VisibleForTesting
    static void removeGpeRuntimeAndFacets(IFacetedProject facetedProject) {
        // To remove the facets, we will directly modify the WTP facet metadata file (using XSLT):
        // .settings/org.eclipse.wst.common.project.facet.core.xml
        IFile metadataFile = facetedProject.getProject().getFile(FACETS_METADATA_FILE);
        if (!metadataFile.exists()) {
            return;
        }

        URL xslt = GpeMigrator.class.getResource(WTP_METADATA_XSLT);
        try {
            Xslt.transformInPlace(metadataFile, xslt);
        } catch (IOException | TransformerException | CoreException ex) {
            logger.log(Level.WARNING, "Failed to modify WTP facet metadata.", ex);
        }
    }

}