org.vosao.utils.StreamUtil.java Source code

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Here is the source code for org.vosao.utils.StreamUtil.java

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/**
 * Vosao CMS. Simple CMS for Google App Engine.
 * 
 * Copyright (C) 2009-2010 Vosao development team.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * email: vosao.dev@gmail.com
 */

package org.vosao.utils;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class StreamUtil {

    private static final Log logger = LogFactory.getLog(StreamUtil.class);

    public static byte[] readFileStream(final InputStream stream) throws IOException {
        byte[] buffer = new byte[4096];
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        long contentLength = 0;
        int n = 0;
        while (-1 != (n = stream.read(buffer))) {
            contentLength += n;
            output.write(buffer, 0, n);
        }
        return output.toByteArray();
    }

    public static String getTextResource(final String path) throws IOException {
        return getTextResource(StreamUtil.class.getClassLoader(), path);
    }

    public static InputStream getResource(ClassLoader classLoader, final String path) throws IOException {
        InputStream in = classLoader.getResourceAsStream(path);
        if (in == null) {
            throw new IOException("Empty resource.");
        }
        return in;
    }

    public static String getTextResource(ClassLoader classLoader, final String path) throws IOException {
        InputStream in = getResource(classLoader, path);
        if (in == null) {
            throw new IOException("Empty input stream.");
        }
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        StringBuffer buf = new StringBuffer();
        while (reader.ready()) {
            buf.append(reader.readLine()).append("\n");
        }
        return buf.toString();
    }

    public static byte[] getBytesResource(final String path) throws IOException {
        return getBytesResource(StreamUtil.class.getClassLoader(), path);
    }

    public static byte[] getBytesResource(ClassLoader classLoader, final String path) throws IOException {
        InputStream in = getResource(classLoader, path);
        if (in == null) {
            throw new IOException("Empty input stream.");
        }
        return IOUtils.toByteArray(in);
    }

    /**
     * Converts an object to an array of bytes . Uses the Logging utilities in
     * j2sdk1.4 for reporting exceptions.
     * 
     * @param object
     *            the object to convert.
     * @return the associated byte array.
     */
    public static byte[] toBytes(Object object) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            ObjectOutputStream oos = new java.io.ObjectOutputStream(baos);
            oos.writeObject(object);
        } catch (IOException ioe) {
            logger.error(ioe.getMessage());
        }
        return baos.toByteArray();
    }

    /**
     * Converts an array of bytes back to its constituent object. The input
     * array is assumed to have been created from the original object. 
     * 
     * @param bytes
     *            the byte array to convert.
     * @return the associated object.
     */
    public static Object toObject(byte[] bytes) {
        Object object = null;
        try {
            object = new ObjectInputStream(new ByteArrayInputStream(bytes)).readObject();
        } catch (IOException ioe) {
            logger.error(ioe.getMessage());
        } catch (ClassNotFoundException cnfe) {
            logger.info(cnfe.getMessage());
        }
        return object;
    }
}