org.apache.olingo.fit.utils.FSManager.java Source code

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/*
 * 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.olingo.fit.utils;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

import javax.ws.rs.NotFoundException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSelectInfo;
import org.apache.commons.vfs2.FileSelector;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemManager;
import org.apache.commons.vfs2.FileType;
import org.apache.commons.vfs2.VFS;
import org.apache.olingo.client.api.data.ResWrap;
import org.apache.olingo.client.api.serialization.ODataSerializerException;
import org.apache.olingo.client.core.serialization.AtomSerializer;
import org.apache.olingo.client.core.serialization.JsonSerializer;
import org.apache.olingo.commons.api.data.Entity;
import org.apache.olingo.commons.api.edm.constants.ODataServiceVersion;
import org.apache.olingo.commons.api.format.ContentType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FSManager {

    /**
     * Logger.
     */
    protected static final Logger LOG = LoggerFactory.getLogger(AbstractUtilities.class);

    private static String MEM_PREFIX = "ram://";

    private static String RES_PREFIX = "res://";

    private final FileSystemManager fsManager;

    private static FSManager instance = null;

    public static FSManager instance() throws IOException {
        if (instance == null) {
            instance = new FSManager();
        }
        return instance;
    }

    private FSManager() throws IOException {
        fsManager = VFS.getManager();

        final FileObject basePath = fsManager
                .resolveFile(RES_PREFIX + File.separatorChar + ODataServiceVersion.V40.name());
        final String absoluteBaseFolder = basePath.getURL().getPath();

        for (FileObject fo : find(basePath, null)) {
            if (fo.getType() == FileType.FILE && !fo.getName().getBaseName().contains("Metadata")
                    && !fo.getName().getBaseName().contains("metadata")) {
                final String path = fo.getURL().getPath().replace(absoluteBaseFolder,
                        "//" + ODataServiceVersion.V40.name());
                putInMemory(fo.getContent().getInputStream(), path);
            }
        }
    }

    public String getAbsolutePath(final String relativePath, final Accept accept) {
        return File.separatorChar + ODataServiceVersion.V40.name() + File.separatorChar + relativePath
                + (accept == null ? "" : accept.getExtension());
    }

    public final FileObject putInMemory(final InputStream is, final String path) throws IOException {
        LOG.info("Write in memory {}", path);
        final FileObject memObject = fsManager.resolveFile(MEM_PREFIX + path);

        if (memObject.exists()) {
            memObject.delete();
        }

        // create in-memory file
        memObject.createFile();

        // read in-memory content
        final OutputStream os = memObject.getContent().getOutputStream();
        IOUtils.copy(is, os);
        IOUtils.closeQuietly(is);
        IOUtils.closeQuietly(os);

        return memObject;
    }

    public void putInMemory(final ResWrap<Entity> container, final String relativePath)
            throws IOException, ODataSerializerException {
        ByteArrayOutputStream content = new ByteArrayOutputStream();
        OutputStreamWriter writer = new OutputStreamWriter(content, Constants.ENCODING);

        new AtomSerializer(true).write(writer, container);
        writer.flush();

        putInMemory(new ByteArrayInputStream(content.toByteArray()), getAbsolutePath(relativePath, Accept.ATOM));
        content.reset();

        new JsonSerializer(true, ContentType.JSON_FULL_METADATA).write(writer, container);
        writer.flush();

        putInMemory(new ByteArrayInputStream(content.toByteArray()),
                getAbsolutePath(relativePath, Accept.JSON_FULLMETA));
    }

    public InputStream readRes(final String relativePath, final Accept accept) {
        return readFile(relativePath, accept, RES_PREFIX);
    }

    public InputStream readFile(final String relativePath, final Accept accept) {
        return readFile(relativePath, accept, MEM_PREFIX);
    }

    public InputStream readFile(final String relativePath) {
        return readFile(relativePath, null, MEM_PREFIX);
    }

    private InputStream readFile(final String relativePath, final Accept accept, final String fs) {
        final String path = getAbsolutePath(relativePath, accept);
        LOG.info("Read {}{}", fs, path);

        try {
            final FileObject fileObject = fsManager.resolveFile(fs + path);

            if (fileObject.exists()) {
                // return new in-memory content
                return fileObject.getContent().getInputStream();
            } else {
                LOG.warn("In-memory path '{}' not found", path);
                throw new NotFoundException();
            }
        } catch (FileSystemException e) {
            throw new NotFoundException();
        }
    }

    public void deleteFile(final String relativePath) {
        for (Accept accept : Accept.values()) {
            final String path = getAbsolutePath(relativePath, accept);
            LOG.info("Delete {}", path);

            try {
                final FileObject fileObject = fsManager.resolveFile(MEM_PREFIX + path);

                if (fileObject.exists()) {
                    fileObject.delete();
                }
            } catch (IOException ignore) {
                // ignore exception
            }
        }
    }

    public void deleteEntity(final String relativePath) {
        final String path = getAbsolutePath(relativePath, null);
        LOG.info("Delete {}", path);

        try {
            final FileObject fileObject = fsManager.resolveFile(MEM_PREFIX + path);

            if (fileObject.exists()) {
                fileObject.delete(new FileSelector() {
                    @Override
                    public boolean includeFile(final FileSelectInfo fileInfo) throws Exception {
                        return true;
                    }

                    @Override
                    public boolean traverseDescendents(final FileSelectInfo fileInfo) throws Exception {
                        return true;
                    }
                });
            }
        } catch (IOException ignore) {
            // ignore exception
        }
    }

    public FileObject resolve(final String path) throws FileSystemException {
        final FileObject res = fsManager.resolveFile(MEM_PREFIX + path);

        if (!res.exists()) {
            throw new FileSystemException("Unresolved path " + path);
        }

        return res;
    }

    public final FileObject[] find(final FileObject fo, final String ext) throws FileSystemException {
        return fo.findFiles(new FileSelector() {
            @Override
            public boolean includeFile(final FileSelectInfo fileInfo) throws Exception {
                return ext == null ? true : fileInfo.getFile().getName().getExtension().equals(ext);
            }

            @Override
            public boolean traverseDescendents(final FileSelectInfo fileInfo) throws Exception {
                return true;
            }
        });
    }
}