com.liferay.portal.kernel.io.Base64OutputStream Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of com.liferay.portal.kernel Show documentation
Contains interfaces for the portal services. Interfaces are only loaded by the global class loader and are shared by all plugins.
There is a newer version: 156.0.0
Show newest version
/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * 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.
 */

package com.liferay.portal.kernel.io;

import com.liferay.portal.kernel.util.CharPool;

import java.io.IOException;
import java.io.OutputStream;

/**
 * @author Tina Tian
 */
public class Base64OutputStream extends OutputStream {

	public Base64OutputStream(OutputStream outputStream) {
		_outputStream = outputStream;
		_unitBuffer = new byte[3];
		_unitBufferIndex = 0;
		_outputBuffer = new byte[4];
	}

	@Override
	public void close() throws IOException {
		flush();

		_outputStream.close();
	}

	@Override
	public void flush() throws IOException {
		if (_unitBufferIndex == 1) {
			encodeUnit(_unitBuffer[0]);
		}
		else if (_unitBufferIndex == 2) {
			encodeUnit(_unitBuffer[0], _unitBuffer[1]);
		}

		_unitBufferIndex = 0;

		_outputStream.flush();
	}

	@Override
	public void write(byte[] bytes) throws IOException {
		write(bytes, 0, bytes.length);
	}

	@Override
	public void write(byte[] bytes, int offset, int length) throws IOException {
		if (length <= 0) {
			return;
		}

		while ((_unitBufferIndex != 0) && (length > 0)) {
			write(bytes[offset++]);

			length--;
		}

		if (length <= 0) {
			return;
		}

		int bytesLength = length - (length % 3);

		length -= bytesLength;

		while (bytesLength > 0) {
			encodeUnit(bytes[offset], bytes[offset + 1], bytes[offset + 2]);

			bytesLength -= 3;
			offset += 3;
		}

		while (length > 0) {
			write(bytes[offset++]);

			length--;
		}
	}

	@Override
	public void write(int byteValue) throws IOException {
		_unitBuffer[_unitBufferIndex++] = (byte)byteValue;

		if (_unitBufferIndex == 3) {
			encodeUnit(_unitBuffer[0], _unitBuffer[1], _unitBuffer[2]);

			_unitBufferIndex = 0;
		}
	}

	protected void encodeUnit(byte byteValue) throws IOException {
		int intValue = byteValue & 0xff;

		intValue <<= 4;

		_outputBuffer[3] = (byte)CharPool.EQUAL;
		_outputBuffer[2] = (byte)CharPool.EQUAL;
		_outputBuffer[1] = (byte)getChar(intValue & 0x3f);

		intValue >>= 6;

		_outputBuffer[0] = (byte)getChar(intValue & 0x3f);

		_outputStream.write(_outputBuffer);
	}

	protected void encodeUnit(byte byte1, byte byte2) throws IOException {
		int intValue = byte1 & 0xff;

		intValue <<= 8;
		intValue |= byte2 & 0xff;
		intValue <<= 2;

		_outputBuffer[3] = (byte)CharPool.EQUAL;
		_outputBuffer[2] = (byte)getChar(intValue & 0x3f);

		intValue >>= 6;

		_outputBuffer[1] = (byte)getChar(intValue & 0x3f);

		intValue >>= 6;

		_outputBuffer[0] = (byte)getChar(intValue & 0x3f);

		_outputStream.write(_outputBuffer);
	}

	protected void encodeUnit(byte byte1, byte byte2, byte byte3)
		throws IOException {

		int intVallue = byte1 & 0xff;

		intVallue <<= 8;
		intVallue |= byte2 & 0xff;
		intVallue <<= 8;
		intVallue |= byte3 & 0xff;

		_outputBuffer[3] = (byte)getChar(intVallue & 0x3f);

		intVallue >>= 6;

		_outputBuffer[2] = (byte)getChar(intVallue & 0x3f);

		intVallue >>= 6;

		_outputBuffer[1] = (byte)getChar(intVallue & 0x3f);

		intVallue >>= 6;

		_outputBuffer[0] = (byte)getChar(intVallue & 0x3f);

		_outputStream.write(_outputBuffer);
	}

	protected char getChar(int sixbit) {
		if ((sixbit >= 0) && (sixbit <= 25)) {
			return (char)(65 + sixbit);
		}

		if ((sixbit >= 26) && (sixbit <= 51)) {
			return (char)(97 + (sixbit - 26));
		}

		if ((sixbit >= 52) && (sixbit <= 61)) {
			return (char)(48 + (sixbit - 52));
		}

		if (sixbit == 62) {
			return CharPool.PLUS;
		}

		if (sixbit != 63) {
			return CharPool.QUESTION;
		}
		else {
			return CharPool.SLASH;
		}
	}

	private final byte[] _outputBuffer;
	private final OutputStream _outputStream;
	private final byte[] _unitBuffer;
	private int _unitBufferIndex;

}