commons-vfs2/src/main/java/org/apache/commons/vfs2/provider/temp/TemporaryFileProvider.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.vfs2.provider.temp;

import java.io.File;
import java.util.Collection;

import org.apache.commons.vfs2.Capability;
import org.apache.commons.vfs2.FileName;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystem;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.provider.AbstractFileProvider;
import org.apache.commons.vfs2.provider.UriParser;
import org.apache.commons.vfs2.provider.local.DefaultLocalFileProvider;
import org.apache.commons.vfs2.provider.local.LocalFileSystem;

/**
 * A provider for temporary files.
 */
public class TemporaryFileProvider extends AbstractFileProvider implements Comparable<Object> {

    private File rootFile;

    /*
     * private final static FileName tmpFileName = new AbstractFileName("tmp", "/") { protected FileName
     * createName(String absPath) { return null; }
     *
     * protected void appendRootUri(StringBuffer buffer) { } };
     */

    public TemporaryFileProvider(final File rootFile) {
        this();

        this.rootFile = rootFile;
    }

    public TemporaryFileProvider() {
    }

    @Override
    public int compareTo(final Object o) {
        final int h1 = hashCode();
        final int h2 = o.hashCode();
        if (h1 < h2) {
            return -1;
        }
        if (h1 > h2) {
            return 1;
        }

        return 0;
    }

    /**
     * Locates a file object, by absolute URI.
     *
     * @param baseFile The base FileObject.
     * @param uri The URI of the file to be located.
     * @param fileSystemOptions FileSystemOptions to use to locate or create the file.
     * @return The FileObject.
     * @throws FileSystemException if an error occurs.
     */
    @Override
    public synchronized FileObject findFile(final FileObject baseFile, final String uri,
            final FileSystemOptions fileSystemOptions) throws FileSystemException {
        // Parse the name
        final StringBuilder buffer = new StringBuilder(uri);
        final String scheme = UriParser.extractScheme(getContext().getFileSystemManager().getSchemes(), uri, buffer);
        UriParser.fixSeparators(buffer);
        UriParser.normalisePath(buffer);
        final String path = buffer.toString();

        // Create the temp file system if it does not exist
        // FileSystem filesystem = findFileSystem( this, (Properties) null);
        FileSystem filesystem = findFileSystem(this, fileSystemOptions);
        if (filesystem == null) {
            if (rootFile == null) {
                rootFile = getContext().getTemporaryFileStore().allocateFile("tempfs");
            }
            final FileName rootName = getContext().parseURI(scheme + ":" + FileName.ROOT_PATH);
            // final FileName rootName =
            // new LocalFileName(scheme, scheme + ":", FileName.ROOT_PATH);
            filesystem = new LocalFileSystem(rootName, rootFile.getAbsolutePath(), fileSystemOptions);
            addFileSystem(this, filesystem);
        }

        // Find the file
        return filesystem.resolveFile(path);
    }

    @Override
    public Collection<Capability> getCapabilities() {
        return DefaultLocalFileProvider.capabilities;
    }
}