package com.tinkerpop.gremlin.server.handler;
import com.tinkerpop.gremlin.driver.message.RequestMessage;
import com.tinkerpop.gremlin.driver.ser.MessageTextSerializer;
import com.tinkerpop.gremlin.driver.ser.SerializationException;
import com.tinkerpop.gremlin.driver.ser.Serializers;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageDecoder;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import java.util.List;
/**
* Decodes the contents of a {@link TextWebSocketFrame}. Text-based frames are always assumed to be
* "application/json" when it comes to serialization.
*
* @author Stephen Mallette (http://stephen.genoprime.com)
*/
public class WsGremlinTextRequestDecoder extends MessageToMessageDecoder<TextWebSocketFrame> {
@Override
protected void decode(final ChannelHandlerContext channelHandlerContext, final TextWebSocketFrame frame, final List<Object> objects) throws Exception {
// the default serializer must be a MessageTextSerializer instance to be compatible with this decoder
final MessageTextSerializer serializer = (MessageTextSerializer) Serializers.DEFAULT_REQUEST_SERIALIZER;
channelHandlerContext.channel().attr(StateKey.SERIALIZER).set(serializer);
channelHandlerContext.channel().attr(StateKey.USE_BINARY).set(false);
try {
objects.add(serializer.deserializeRequest(frame.text()));
} catch (SerializationException se) {
objects.add(RequestMessage.INVALID);
}
}
}