ResourceAccess.java

package org.xpect.util;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import org.apache.log4j.Logger;
import org.eclipse.emf.common.util.URI;
import org.eclipse.xtext.util.Strings;
import org.xpect.util.IBundleInfo.Context;

import com.google.common.base.Objects;
import com.google.common.base.Objects.ToStringHelper;
import com.google.common.base.Predicate;
import com.google.common.collect.Lists;

public class ResourceAccess {
	public static class ArchivedResourceInfo extends ResourceInfo {
		public static final Logger LOG = Logger.getLogger(ArchivedResourceInfo.class);

		public ArchivedResourceInfo(URI location) {
			super(location);
		}

		@Override
		public List<URI> find(Context context) {
			return Collections.singletonList(location);
		}

		@Override
		public URI find(Context context, String fileName) {
			return resolve(fileName);
		}

		@Override
		public List<URI> find(Context context, String path, Predicate<String> matcher, String... fileExtensions) {
			String archiveFileName = URI.createURI(location.authority().substring(0, location.authority().length() - 1)).toFileString();
			List<URI> result = Lists.newArrayList();
			try {
				JarFile jarFile = new JarFile(new File(archiveFileName));
				try {
					Enumeration<JarEntry> entries = jarFile.entries();
					while (entries.hasMoreElements()) {
						JarEntry next = entries.nextElement();
						String name = next.getName();
						if (!Strings.isEmpty(path) && !name.startsWith(path))
							continue;
						if (matches(name, fileExtensions) && matcher.apply(name)) {
							URI resolved = URI.createURI(name).resolve(location);
							result.add(resolved);
						}
					}
				} finally {
					if (jarFile != null)
						jarFile.close();
				}
			} catch (IOException e) {
				LOG.error(e.getMessage(), e);
			}
			return result;
		}

		@Override
		public String toString() {
			return Objects.toStringHelper(this).add("location", location.toString()).toString();
		}

	}

	public static class GeneralProjectInfo extends ResourceInfo {

		public GeneralProjectInfo(URI location) {
			super(location);
		}

		@Override
		public List<URI> find(Context context) {
			return Collections.singletonList(location);
		}

		@Override
		public URI find(Context context, String fileName) {
			return resolve(fileName);
		}

		@Override
		public List<URI> find(Context context, String path, Predicate<String> matcher, String... fileExtensions) {
			File root = new File(location.toFileString());
			List<URI> result = Lists.newArrayList();
			collect(root, root, result, matcher, fileExtensions);
			return result;
		}

		@Override
		public String toString() {
			return Objects.toStringHelper(this).add("location", location.toString()).toString();
		}

	}

	public static class JavaProjectInfo extends ResourceInfo {

		private final String output;

		private final List<String> sourceFolders;

		public JavaProjectInfo(URI location, List<String> sourceFolders, String output) {
			super(location);
			this.sourceFolders = sourceFolders;
			this.output = output;
		}

		@Override
		public List<URI> find(Context context) {
			switch (context) {
			case CLASSPATH:
				return Collections.singletonList(resolve(output));
			case ROOT:
				return Collections.singletonList(location);
			case SOURCE:
				List<URI> result = Lists.newArrayList();
				for (String src : sourceFolders)
					result.add(resolve(src));
				return result;
			}
			return Collections.emptyList();
		}

		@Override
		public URI find(Context context, String fileName) {
			for (URI uri : find(context)) {
				File parent = new File(uri.toFileString());
				if (new File(parent, fileName).exists())
					return URI.createURI(fileName).resolve(uri.hasTrailingPathSeparator() ? uri : uri.appendSegment(""));
			}
			return null;
		}

		@Override
		public List<URI> find(Context context, String path, Predicate<String> matcher, String... fileExtensions) {
			List<URI> result = Lists.newArrayList();
			for (URI uri : find(context)) {
				File folder = new File(new File(uri.toFileString()), path);
				if (folder.isDirectory()) {
					collect(folder, folder, result, matcher, fileExtensions);
				}
			}
			return result;
		}

		@Override
		public String toString() {
			ToStringHelper helper = Objects.toStringHelper(this);
			helper.add("location", location.toString());
			helper.add("classpath", output);
			helper.add("source", sourceFolders);
			return helper.toString();
		}

	}

	public abstract static class ResourceInfo {
		protected final URI location;

		public ResourceInfo(URI location) {
			super();
			this.location = location;
		}

		protected void collect(File root, File file, List<URI> result, Predicate<String> matcher, String... fileExtensions) {
			if (file.isFile()) {
				if (matches(file.getName(), fileExtensions)) {
					URI uri = URI.createFileURI(file.getAbsolutePath());
					URI name = uri.deresolve(URI.createURI(root.toString()));
					if (matcher.apply(name.toString())) {
						result.add(uri);
					}
				}
			} else if (file.isDirectory()) {
				for (File child : file.listFiles())
					collect(root, child, result, matcher, fileExtensions);
			}
		}

		public abstract List<URI> find(Context context);

		public abstract URI find(Context context, String fileName);

		public abstract List<URI> find(Context context, String path, Predicate<String> matcher, String... fileExtensions);

		public URI getLocation() {
			return location;
		}

		protected boolean matches(String name, String... fileExtensions) {
			if (fileExtensions.length == 0)
				return true;
			int index = name.lastIndexOf('.');
			if (index < 0)
				return false;
			String ext = name.substring(index + 1, name.length());
			for (int i = 0; i < fileExtensions.length; i++)
				if (ext.equals(fileExtensions[i]))
					return true;
			return false;
		}

		protected URI resolve(String fileName) {
			return URI.createURI(fileName).resolve(location);
		}

	}

	public static ResourceInfo create(URI uri) {
		if (uri.isArchive())
			return new ArchivedResourceInfo(uri);
		else {
			File dot = new File(uri.toFileString() + ".classpath");
			if (dot.isFile()) {
				DotClasspath dotClasspath = new DotClasspath(dot);
				return new JavaProjectInfo(uri, dotClasspath.getSources(), dotClasspath.getOutput());
			}
			return new GeneralProjectInfo(uri);
		}
	}

}