net.sourceforge.vaticanfetcher.model.index.outlook.AttachmentVisitor.java Source code

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Here is the source code for net.sourceforge.vaticanfetcher.model.index.outlook.AttachmentVisitor.java

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/*******************************************************************************
 * Copyright (c) 2011 Tran Nam Quang.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Tran Nam Quang - initial API and implementation
 *******************************************************************************/

package net.sourceforge.vaticanfetcher.model.index.outlook;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;

import net.sourceforge.vaticanfetcher.model.index.IndexingConfig;
import net.sourceforge.vaticanfetcher.model.index.IndexingException;
import net.sourceforge.vaticanfetcher.model.parse.ParseException;
import net.sourceforge.vaticanfetcher.util.CheckedOutOfMemoryError;
import net.sourceforge.vaticanfetcher.util.Util;
import net.sourceforge.vaticanfetcher.util.annotations.NotNull;

import com.google.common.io.Closeables;
import com.pff.PSTAttachment;
import com.pff.PSTMessage;

abstract class AttachmentVisitor {

    private final IndexingConfig config;
    private final PSTMessage email;
    private final boolean deleteTempFiles;

    public AttachmentVisitor(@NotNull IndexingConfig config, @NotNull PSTMessage email, boolean deleteTempFiles) {
        Util.checkNotNull(config, email);
        this.config = config;
        this.email = email;
        this.deleteTempFiles = deleteTempFiles;
    }

    public final void run() {
        int numberOfAttachments = email.getNumberOfAttachments();
        for (int i = 0; i < numberOfAttachments; i++) {
            String filename = null;
            File tempFile = null;
            try {
                PSTAttachment attach = email.getAttachment(i);

                // Get the filename; both long and short filenames can be used for attachments
                filename = attach.getLongFilename();
                if (filename.isEmpty())
                    filename = attach.getFilename();

                // Set up input and output stream
                tempFile = config.createDerivedTempFile(filename);
                InputStream in = attach.getFileInputStream();
                FileOutputStream out = new FileOutputStream(tempFile);

                /*
                 * TODO post-release-1.1: Instead of writing to a temporary
                 * file, we could directly give the input stream to the parse
                 * service. (But temporary files would still be necessary for
                 * archives.)
                 */

                /*
                 * Copy bytes from input stream to output stream
                 * 
                 * 8176 is the block size used internally and should give the
                 * best performance.
                 */
                int bufferSize = 8176;
                byte[] buffer = new byte[bufferSize];
                int count = in.read(buffer);
                while (count == bufferSize) {
                    out.write(buffer);
                    count = in.read(buffer);
                }
                byte[] endBuffer = new byte[count];
                System.arraycopy(buffer, 0, endBuffer, 0, count);
                out.write(endBuffer);
                Closeables.closeQuietly(out);
                Closeables.closeQuietly(in);

                handleAttachment(filename, tempFile);
            } catch (CheckedOutOfMemoryError e) {
                if (filename == null)
                    filename = "???";
                handleException(filename, e.getCause());
            } catch (Exception e) {
                if (filename == null)
                    filename = "???";
                if (e instanceof IndexingException)
                    e = ((IndexingException) e).getIOException();
                handleException(filename, e);
            } finally {
                if (deleteTempFiles && tempFile != null)
                    tempFile.delete();
            }
        }
        runFinally();
    }

    protected abstract void handleAttachment(@NotNull String filename, @NotNull File tempFile)
            throws ParseException, CheckedOutOfMemoryError;

    protected abstract void handleException(@NotNull String filename, @NotNull Throwable e);

    protected void runFinally() {
    }

}