com.att.nsa.util.StreamTools Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of saToolkit Show documentation
Library of code used in various service assurance systems
There is a newer version: 1.2.0-oss
/*******************************************************************************
 * Copyright (c) 2016 AT&T Intellectual Property. All rights reserved.
 *******************************************************************************/
package com.att.nsa.util;

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

public class StreamTools
{
	protected static final int kBufferLength = 4096;

	/**
	 * Reads the stream into a byte array using a default-sized array for each read,
	 * then closes the input stream.
	 * 
	 * @param is
	 * @param bufferSize
	 * @return a byte array
	 * @throws IOException
	 */
	public static byte[] readBytes ( InputStream is ) throws IOException
	{
		return readBytes ( is, kBufferLength );
	}

	/**
	 * Reads the stream into a byte array using a bufferSize array for each read,
	 * then closes the input stream.
	 * 
	 * @param is
	 * @param bufferSize
	 * @return a byte array
	 * @throws IOException
	 */
	public static byte[] readBytes ( InputStream is, int bufferSize ) throws IOException
	{
		return readBytes ( is, bufferSize, -1 );
	}

	/**
	 * Reads the stream into a byte array using a bufferSize array for each read,
	 * then closes the input stream. If limit >= 0, at most limit bytes are read.

	 * Note: even with a negative limit, 2GB is the limit.
	 * 
	 * @param is
	 * @param bufferSize
	 * @param limit
	 * @return a byte array
	 * @throws IOException
	 */
	public static byte[] readBytes ( InputStream is, int bufferSize, int limit ) throws IOException
	{
		int counter = 0;
		final int atMost = limit < 0 ? Integer.MAX_VALUE : Math.min ( limit, Integer.MAX_VALUE );

		final ByteArrayOutputStream baos = new ByteArrayOutputStream ();
		if ( is != null )
		{
			byte[] b = new byte [ bufferSize ];
			int len = 0;
			do
			{
				len = is.read ( b );
				if ( -1 != len )
				{
					final int readNow = Math.min ( len, atMost - counter );
					baos.write ( b, 0, readNow );
					counter += readNow;
				}
			}
			while ( len != -1 && counter < atMost );
			is.close ();
		}

		return baos.toByteArray ();
	}

	/**
	 * Copy from the input stream to the output stream, then close the output stream.
	 * @param in
	 * @param out
	 * @throws IOException
	 */
	public static void copyStream ( InputStream in, OutputStream out ) throws IOException
	{
		copyStream ( in, out, kBufferLength );
	}

	/**
	 * Copy from the input stream to the output stream, then close the output stream.
	 * @param in
	 * @param out
	 * @param bufferSize
	 * @throws IOException
	 */
	public static void copyStream ( InputStream in, OutputStream out, int bufferSize ) throws IOException
	{
		final byte[] buffer = new byte [bufferSize];
		int len;
		while ( ( len = in.read ( buffer ) ) != -1 )
		{
			out.write ( buffer, 0, len );
		}
		out.close ();
	}
}