Application: gvSIG desktop

package org.gvsig.fmap.dal.spi;

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.net.URI;

import java.net.URISyntaxException;

import java.net.URL;

import java.nio.file.FileSystem;

import java.nio.file.FileSystems;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.StandardCopyOption;

import java.util.Collections;

import java.util.Objects;

import java.util.zip.ZipEntry;

import java.util.zip.ZipFile;

import org.apache.commons.io.IOUtils;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.fmap.dal.AbstractDataResource;

import org.gvsig.tools.util.ResourcesStorage.Resource;

import org.slf4j.LoggerFactory;

/**

 *

 * @author jjdelcerro

 */

@SuppressWarnings("UseSpecificCatch")

public class FileMultiResource

        extends AbstractDataResource

        implements Resource {

    private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(FileMultiResource.class);

    private final File zipFile;

    private final String tableName;

    private final String resourceName;

    private ZipFile zip;

    private InputStream in;

    private ByteArrayOutputStream out;

    public FileMultiResource(File zipFile, String tableName, String resourceName) {

        this.zipFile = new File(zipFile.getAbsolutePath() + ".gvres");

        this.tableName = tableName;

        this.resourceName = resourceName;

        this.zip = null;

        this.in = null;

        this.out = null;

        if( StringUtils.isBlank(this.tableName) ) {

            LOGGER.warn("The table name is empty (URL="+this.getURL()+").");

        }

        if( StringUtils.isBlank(this.resourceName) ) {

            LOGGER.warn("The resource name is empty (URL="+this.getURL()+").");

        }

    }

    @Override

    public URL getURL() {

        try {

            return new URL("jar:" + this.zipFile.toURI().toString() + "!/" + this.tableName + "." + this.resourceName);

        } catch (Exception ex) {

            return null;

        }

    }

    @Override

    public boolean exists() {

        try {

            if (!this.zipFile.exists()) {

                return false;

            }

            ZipFile z = new ZipFile(zipFile);

            try {

                ZipEntry entry = z.getEntry(this.tableName + "." + this.resourceName);

                if (entry == null) {

                    return false;

                }

                return true;

            } finally {

                IOUtils.closeQuietly(z);

            }

        } catch (Exception ex) {

            LOGGER.warn("Can't access to the resource (" + Objects.toString(this.getURL()) + ").", ex);

            return false;

        }

    }

    @Override

    public InputStream asInputStream() throws IOException {

        if (!this.zipFile.exists()) {

            return null;

        }

        if (this.in != null || this.out != null) {

            throw new IllegalStateException("Resource is already open (" + this.zipFile.toString() + "!" + this.tableName + ")");

        }

        try {

            if( this.zip == null ) {

                this.zip = new ZipFile(zipFile);

            }

            ZipEntry entry = this.zip.getEntry(this.tableName + "." + this.resourceName);

            if (entry == null) {

                return null;

            }

            this.in = this.zip.getInputStream(entry);

            return this.in;

        } catch (Exception ex) {

            LOGGER.warn("Can't create input stream (" + Objects.toString(this.getURL()) + ").", ex);

            return null;

        }

    }

    @Override

    public OutputStream asOutputStream() throws IOException {

        if (this.in != null || this.out != null) {

            throw new IllegalStateException("Resource is already open (" + Objects.toString(this.getURL()) + ").");

        }

        this.out = new ByteArrayOutputStream();

        return this.out;

    }

    @Override

    public void close() {

        if (this.in != null) {

            IOUtils.closeQuietly(this.in);

            this.in = null;

        }

        if (this.out != null) {

            ByteArrayInputStream contents = new ByteArrayInputStream(this.out.toByteArray());

            try {

                this.updateZipEntry(zipFile, this.tableName + "." + this.resourceName, contents);

            } catch (Exception ex) {

                LOGGER.warn("Can't write resource (" + Objects.toString(this.getURL()) + ").", ex);

            } finally {

                IOUtils.closeQuietly(contents);

                IOUtils.closeQuietly(this.out);

                this.out = null;

            }

        }

        if (this.zip != null) {

            IOUtils.closeQuietly(this.zip);

            this.zip = null;

        }

    }

    private void updateZipEntry(File zip, String entryName, InputStream entryContents) throws URISyntaxException, IOException {

        FileSystem zipfs = null;

        try {

            URI zipfsuri = new URI("jar:" + zip.toURI().toString());

            zipfs = FileSystems.newFileSystem(zipfsuri, Collections.singletonMap("create", "true"));

            Path entryPath = zipfs.getPath(entryName);

            Files.copy(entryContents, entryPath, StandardCopyOption.REPLACE_EXISTING);

        } finally {

            IOUtils.closeQuietly(zipfs);

        }

    }

}