HttpObjectAggregator Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectAggregator.java lines 86–566

public class HttpObjectAggregator
        extends MessageAggregator<HttpObject, HttpMessage, HttpContent, FullHttpMessage> {
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(HttpObjectAggregator.class);
    private static final FullHttpResponse CONTINUE =
            new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CONTINUE, Unpooled.EMPTY_BUFFER);
    private static final FullHttpResponse EXPECTATION_FAILED = new DefaultFullHttpResponse(
            HttpVersion.HTTP_1_1, HttpResponseStatus.EXPECTATION_FAILED, Unpooled.EMPTY_BUFFER);
    private static final FullHttpResponse TOO_LARGE_CLOSE = new DefaultFullHttpResponse(
            HttpVersion.HTTP_1_1, HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE, Unpooled.EMPTY_BUFFER);
    private static final FullHttpResponse TOO_LARGE = new DefaultFullHttpResponse(
        HttpVersion.HTTP_1_1, HttpResponseStatus.REQUEST_ENTITY_TOO_LARGE, Unpooled.EMPTY_BUFFER);

    static {
        EXPECTATION_FAILED.headers().set(CONTENT_LENGTH, 0);
        TOO_LARGE.headers().set(CONTENT_LENGTH, 0);

        TOO_LARGE_CLOSE.headers().set(CONTENT_LENGTH, 0);
        TOO_LARGE_CLOSE.headers().set(CONNECTION, HttpHeaderValues.CLOSE);
    }

    private final boolean closeOnExpectationFailed;

    /**
     * Creates a new instance.
     * @param maxContentLength the maximum length of the aggregated content in bytes.
     * If the length of the aggregated content exceeds this value,
     * {@link #handleOversizedMessage(ChannelHandlerContext, HttpMessage)} will be called.
     */
    public HttpObjectAggregator(int maxContentLength) {
        this(maxContentLength, false);
    }

    /**
     * Creates a new instance.
     * @param maxContentLength the maximum length of the aggregated content in bytes.
     * If the length of the aggregated content exceeds this value,
     * {@link #handleOversizedMessage(ChannelHandlerContext, HttpMessage)} will be called.
     * @param closeOnExpectationFailed If a 100-continue response is detected but the content length is too large
     * then {@code true} means close the connection. otherwise the connection will remain open and data will be
     * consumed and discarded until the next request is received.
     */
    public HttpObjectAggregator(int maxContentLength, boolean closeOnExpectationFailed) {
        super(maxContentLength, HttpObject.class);
        this.closeOnExpectationFailed = closeOnExpectationFailed;
    }

    @Override
    protected boolean isStartMessage(HttpObject msg) throws Exception {
        return msg instanceof HttpMessage;
    }

    @Override
    protected boolean isContentMessage(HttpObject msg) throws Exception {
        return msg instanceof HttpContent;
    }

    @Override
    protected boolean isLastContentMessage(HttpContent msg) throws Exception {
        return msg instanceof LastHttpContent;
    }

    @Override
    protected boolean isAggregated(HttpObject msg) throws Exception {
        return msg instanceof FullHttpMessage;
    }

    @Override
    protected boolean isContentLengthInvalid(HttpMessage start, int maxContentLength) {
        try {
            return getContentLength(start, -1L) > maxContentLength;
        } catch (final NumberFormatException e) {
            return false;
        }
    }

    private Object continueResponse(HttpMessage start, int maxContentLength, ChannelPipeline pipeline) {
        if (HttpUtil.isUnsupportedExpectation(start)) {
            // if the request contains an unsupported expectation, we return 417
            pipeline.fireUserEventTriggered(HttpExpectationFailedEvent.INSTANCE);
            return EXPECTATION_FAILED.retainedDuplicate();
        } else if (HttpUtil.is100ContinueExpected(start)) {