ratpack.server.internal.BaseDirFinder.java Source code

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Here is the source code for ratpack.server.internal.BaseDirFinder.java

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/*
 * Copyright 2015 the original author or authors.
 *
 * 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 ratpack.server.internal;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.sun.nio.zipfs.ZipFileSystemProvider;

import java.io.IOException;
import java.net.URI;
import java.net.URL;
import java.nio.file.*;
import java.util.Optional;

import static ratpack.util.Exceptions.uncheck;

public abstract class BaseDirFinder {

    public static class Result {
        private final Path baseDir;
        private final Path resource;

        private Result(Path baseDir, Path resource) {
            this.baseDir = baseDir;
            this.resource = resource;
        }

        public Path getBaseDir() {
            return baseDir;
        }

        public Path getResource() {
            return resource;
        }

        @Override
        public String toString() {
            return "Result{baseDir=" + baseDir + ", resource=" + resource + '}';
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }

            Result result = (Result) o;

            return baseDir.equals(result.baseDir) && resource.equals(result.resource);
        }

        @Override
        public int hashCode() {
            int result = baseDir.hashCode();
            result = 31 * result + resource.hashCode();
            return result;
        }
    }

    public static Optional<Result> find(String workingDir, ClassLoader classLoader, String resourcePathString) {
        Path resourcePath;
        URL resourceUrl = classLoader.getResource(resourcePathString);
        if (resourceUrl == null) {
            resourcePath = Paths.get(resourcePathString);
            if (!resourcePath.isAbsolute()) {
                resourcePath = Paths.get(workingDir, resourcePathString);
            }

            if (!Files.exists(resourcePath)) {
                return Optional.empty();
            }
        } else {
            resourcePath = toPath(resourceUrl);
        }

        return Optional.of(new Result(determineBaseDir(resourcePath), resourcePath));
    }

    private static Path toPath(URL resource) {
        URI uri = uncheck(resource::toURI);

        String scheme = uri.getScheme();
        if (scheme.equals("file")) {
            return Paths.get(uri);
        }

        if (!scheme.equals("jar")) {
            throw new IllegalStateException("Cannot deal with class path resource url: " + uri);
        }

        String s = uri.toString();
        int separator = s.indexOf("!/");
        String entryName = s.substring(separator + 2);
        URI fileURI = URI.create(s.substring(0, separator));
        FileSystem fs = null;
        try {
            // Check if there's an existing file system, since it's provider-dependent whether file systems with the same URI are allowed
            fs = FileSystems.getFileSystem(fileURI);
            if (!fs.isOpen()) { // It's provider-dependent whether to return closed file systems
                fs = null; // Ignore it; closed file systems can't be used
            }
        } catch (FileSystemNotFoundException ignore) {
            // Continue to create the file system
        }
        if (fs == null) {
            try {
                fs = FileSystems.newFileSystem(fileURI, ImmutableMap.of());
            } catch (IOException e) {
                throw uncheck(e);
            }
        }
        return fs.getPath(entryName);
    }

    private static Path determineBaseDir(Path configPath) {
        Path baseDir = configPath.getParent();
        if (baseDir == null && configPath.getFileSystem().provider() instanceof ZipFileSystemProvider) {
            baseDir = Iterables.getFirst(configPath.getFileSystem().getRootDirectories(), null);
        }
        if (baseDir == null) {
            throw new IllegalStateException("Cannot determine base dir given config resource: " + configPath);
        }
        return baseDir;
    }

}