cloudeventbus.codec.Encoder.java Source code

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Here is the source code for cloudeventbus.codec.Encoder.java

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/*
 *   Copyright (c) 2012 Mike Heath.  All rights reserved.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */
package cloudeventbus.codec;

import cloudeventbus.pki.CertificateStoreLoader;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import io.netty.util.CharsetUtil;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Base64OutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

/**
 * @author Mike Heath <elcapo@gmail.com>
 */
public class Encoder extends MessageToByteEncoder<Frame> {

    private static final Logger LOGGER = LoggerFactory.getLogger(Encoder.class);

    @Override
    public void encode(ChannelHandlerContext ctx, Frame frame, ByteBuf out) throws Exception {
        LOGGER.debug("Encoding frame {}", frame);
        switch (frame.getFrameType()) {
        case AUTHENTICATE:
            final AuthenticationRequestFrame authenticationRequestFrame = (AuthenticationRequestFrame) frame;
            out.writeByte(FrameType.AUTHENTICATE.getOpcode());
            out.writeByte(' ');
            final String challenge = Base64.encodeBase64String(authenticationRequestFrame.getChallenge());
            writeString(out, challenge);
            break;
        case AUTH_RESPONSE:
            final AuthenticationResponseFrame authenticationResponseFrame = (AuthenticationResponseFrame) frame;
            out.writeByte(FrameType.AUTH_RESPONSE.getOpcode());
            out.writeByte(' ');

            // Write certificate chain
            final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            final OutputStream base64Out = new Base64OutputStream(outputStream, true, Integer.MAX_VALUE,
                    new byte[0]);
            CertificateStoreLoader.store(base64Out, authenticationResponseFrame.getCertificates());
            out.writeBytes(outputStream.toByteArray());
            out.writeByte(' ');

            // Write salt
            final byte[] encodedSalt = Base64.encodeBase64(authenticationResponseFrame.getSalt());
            out.writeBytes(encodedSalt);
            out.writeByte(' ');

            // Write signature
            final byte[] encodedDigitalSignature = Base64
                    .encodeBase64(authenticationResponseFrame.getDigitalSignature());
            out.writeBytes(encodedDigitalSignature);
            break;
        case ERROR:
            final ErrorFrame errorFrame = (ErrorFrame) frame;
            out.writeByte(FrameType.ERROR.getOpcode());
            out.writeByte(' ');
            writeString(out, Integer.toString(errorFrame.getCode().getErrorNumber()));
            if (errorFrame.getMessage() != null) {
                out.writeByte(' ');
                writeString(out, errorFrame.getMessage());
            }
            break;
        case GREETING:
            final GreetingFrame greetingFrame = (GreetingFrame) frame;
            out.writeByte(FrameType.GREETING.getOpcode());
            out.writeByte(' ');
            writeString(out, Integer.toString(greetingFrame.getVersion()));
            out.writeByte(' ');
            writeString(out, greetingFrame.getAgent());
            out.writeByte(' ');
            writeString(out, Long.toString(greetingFrame.getId()));
            break;
        case PING:
            out.writeByte(FrameType.PING.getOpcode());
            break;
        case PONG:
            out.writeByte(FrameType.PONG.getOpcode());
            break;
        case PUBLISH:
            final PublishFrame publishFrame = (PublishFrame) frame;
            out.writeByte(FrameType.PUBLISH.getOpcode());
            out.writeByte(' ');
            writeString(out, publishFrame.getSubject().toString());
            if (publishFrame.getReplySubject() != null) {
                out.writeByte(' ');
                writeString(out, publishFrame.getReplySubject().toString());
            }
            out.writeByte(' ');
            final ByteBuf body = Unpooled.wrappedBuffer(publishFrame.getBody().getBytes(CharsetUtil.UTF_8));
            writeString(out, Integer.toString(body.readableBytes()));
            out.writeBytes(Codec.DELIMITER);
            out.writeBytes(body);
            break;
        case SERVER_READY:
            out.writeByte(FrameType.SERVER_READY.getOpcode());
            break;
        case SUBSCRIBE:
            final SubscribeFrame subscribeFrame = (SubscribeFrame) frame;
            out.writeByte(FrameType.SUBSCRIBE.getOpcode());
            out.writeByte(' ');
            writeString(out, subscribeFrame.getSubject().toString());
            break;
        case UNSUBSCRIBE:
            final UnsubscribeFrame unsubscribeFrame = (UnsubscribeFrame) frame;
            out.writeByte(FrameType.UNSUBSCRIBE.getOpcode());
            out.writeByte(' ');
            writeString(out, unsubscribeFrame.getSubject().toString());
            break;
        default:
            throw new EncodingException("Don't know how to encode message of type " + frame.getClass().getName());
        }
        out.writeBytes(Codec.DELIMITER);
    }

    private void writeString(ByteBuf out, String string) {
        out.writeBytes(string.getBytes(CharsetUtil.UTF_8));
    }

}