constructedoctetstream.java

java 文件下载器。可自定义

// Decompiled by Jad v1.5.8e2. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://kpdus.tripod.com/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi space 
// Source File Name:   ConstructedOctetStream.java

package org.bouncycastle.asn1;

import java.io.IOException;
import java.io.InputStream;

// Referenced classes of package org.bouncycastle.asn1:
//			ASN1ObjectParser, ASN1OctetStringParser

class ConstructedOctetStream extends InputStream
{

	private final ASN1ObjectParser _parser;
	private boolean _first;
	private InputStream _currentStream;

	ConstructedOctetStream(ASN1ObjectParser parser)
	{
		_first = true;
		_parser = parser;
	}

	public int read(byte b[], int off, int len)
		throws IOException
	{
		if (_currentStream == null)
		{
			if (!_first)
				return -1;
			ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
			if (s == null)
				return -1;
			_first = false;
			_currentStream = s.getOctetStream();
		}
		int totalRead = 0;
		do
		{
			int numRead = _currentStream.read(b, off + totalRead, len - totalRead);
			if (numRead >= 0)
			{
				totalRead += numRead;
				if (totalRead == len)
					return totalRead;
			} else
			{
				ASN1OctetStringParser aos = (ASN1OctetStringParser)_parser.readObject();
				if (aos == null)
				{
					_currentStream = null;
					return totalRead >= 1 ? totalRead : -1;
				}
				_currentStream = aos.getOctetStream();
			}
		} while (true);
	}

	public int read()
		throws IOException
	{
		if (_currentStream == null)
		{
			if (!_first)
				return -1;
			ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
			if (s == null)
				return -1;
			_first = false;
			_currentStream = s.getOctetStream();
		}
		do
		{
			int b = _currentStream.read();
			if (b >= 0)
				return b;
			ASN1OctetStringParser s = (ASN1OctetStringParser)_parser.readObject();
			if (s == null)
			{
				_currentStream = null;
				return -1;
			}
			_currentStream = s.getOctetStream();
		} while (true);
	}
}