org.cyclades.io.StreamUtils Maven / Gradle / Ivy

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 * Copyright (c) 2012, THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY
 * All rights reserved.
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 *    may be used to endorse or promote products derived from this software without
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package org.cyclades.io;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * This class will encapsulate some general methods for IO that have been
 * found to be rewritten frequently.
 *
 */
public class StreamUtils {
    
    /**
     * Write from a URI to an OutpusStream
     * Note: It is the callers responsibility to close the OutputStream
     */
    public static void write (String URI, OutputStream out) throws Exception {
        write (URI, out, DEFAULT_BUFFER_SIZE);

    }

    /**
     * Write from a URI to an OutpusStream
     * Note: It is the callers responsibility to close the OutputStream
     *
     * @param URI
     * @param out
     * @param bufferSize - is now ignored
     * @throws Exception
     */
    public static void write (String URI, OutputStream out, int bufferSize) throws Exception {
        InputStream is = null;
        try {
            if (bufferSize < 1) throw new Exception("Invalid buffer size: " + bufferSize);
            is = ResourceRequestUtils.getInputStream(URI, null);
            write(is, out);
        } catch (Exception ex) {
            throw new Exception(ex);

        } finally {
            try {
                is.close();
            } catch (Exception ignore) {}
        }
    }
    
    /**
     * Write from an InputStream to an OutputStream
     * NOTE: It is the callers responsibility to close both streams
     * 
     * @param is
     * @param out
     * @throws Exception
     */
    public static void write (InputStream is, OutputStream out) throws Exception {
        write(is, out, DEFAULT_BUFFER_SIZE);
    }
    
    /**
     * Write from an InputStream to an OutputStream
     * NOTE: It is the callers responsibility to close both streams
     * 
     * @param is
     * @param out
     * @param bufferSize
     * @throws Exception
     */
    public static void write (InputStream is, OutputStream out, int bufferSize) throws Exception {
        final String eLabel = "StreamUtils.write(InputStream, OutputStream): ";
        try {
            if (bufferSize < 1) throw new Exception("Invalid buffer size: " + bufferSize);
            int bytesRead;
            byte[] buffer = new byte[bufferSize];
            while ((bytesRead = is.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }
        } catch (Exception e) {
            throw new Exception(eLabel + e);
        }
    }
    
    /**
     * Create and return a byte array from an InputStream
     * NOTE: It is the callers responsibility to close the InputStream
     * 
     * @param is
     * @return The byte array representation of the InputStream
     * @throws Exception
     */
    public static byte[] toByteArray (InputStream is) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        write(is, baos);
        return baos.toByteArray();
    }
    
    public static final int DEFAULT_BUFFER_SIZE = 1024;
    
}