Response.java

/*
 * Copyright 2010 Ning, Inc.
 *
 * This program is licensed to you 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 org.asynchttpclient;

import io.netty.buffer.ByteBuf;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.cookie.Cookie;
import org.asynchttpclient.netty.NettyResponse;
import org.asynchttpclient.uri.Uri;
import org.jetbrains.annotations.Nullable;

import java.io.InputStream;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

/**
 * Represents the asynchronous HTTP response callback for an {@link AsyncCompletionHandler}
 */
public interface Response {
    /**
     * Returns the status code for the request.
     *
     * @return The status code
     */
    int getStatusCode();

    /**
     * Returns the status text for the request.
     *
     * @return The status text
     */
    String getStatusText();

    /**
     * Return the entire response body as a byte[].
     *
     * @return the entire response body as a byte[].
     */
    byte[] getResponseBodyAsBytes();

    /**
     * Return the entire response body as a ByteBuffer.
     *
     * @return the entire response body as a ByteBuffer.
     */
    ByteBuffer getResponseBodyAsByteBuffer();

    /**
     * Return the entire response body as a ByteBuf.
     *
     * @return the entire response body as a ByteBuf.
     */
    ByteBuf getResponseBodyAsByteBuf();

    /**
     * Returns an input stream for the response body. Note that you should not try to get this more than once, and that you should not close the stream.
     *
     * @return The input stream
     */
    InputStream getResponseBodyAsStream();

    /**
     * Return the entire response body as a String.
     *
     * @param charset the charset to use when decoding the stream
     * @return the entire response body as a String.
     */
    String getResponseBody(Charset charset);

    /**
     * Return the entire response body as a String.
     *
     * @return the entire response body as a String.
     */
    String getResponseBody();

    /**
     * Return the request {@link Uri}. Note that if the request got redirected, the value of the {@link Uri} will be the last valid redirect url.
     *
     * @return the request {@link Uri}.
     */
    Uri getUri();

    /**
     * Return the content-type header value.
     *
     * @return the content-type header value.
     */
    String getContentType();

    /**
     * @param name the header name
     * @return the first response header value
     */
    String getHeader(CharSequence name);

    /**
     * Return a {@link List} of the response header value.
     *
     * @param name the header name
     * @return the response header value
     */
    List<String> getHeaders(CharSequence name);

    HttpHeaders getHeaders();

    /**
     * Return true if the response redirects to another object.
     *
     * @return True if the response redirects to another object.
     */
    boolean isRedirected();

    /**
     * Subclasses SHOULD implement toString() in a way that identifies the response for logging.
     *
     * @return the textual representation
     */
    @Override
    String toString();

    /**
     * @return the list of {@link Cookie}.
     */
    List<Cookie> getCookies();

    /**
     * Return true if the response's status has been computed by an {@link AsyncHandler}
     *
     * @return true if the response's status has been computed by an {@link AsyncHandler}
     */
    boolean hasResponseStatus();

    /**
     * Return true if the response's headers has been computed by an {@link AsyncHandler} It will return false if the either
     * {@link AsyncHandler#onStatusReceived(HttpResponseStatus)} or {@link AsyncHandler#onHeadersReceived(HttpHeaders)} returned {@link AsyncHandler.State#ABORT}
     *
     * @return true if the response's headers has been computed by an {@link AsyncHandler}
     */
    boolean hasResponseHeaders();

    /**
     * Return true if the response's body has been computed by an {@link AsyncHandler}.
     * It will return false if:
     * <ul>
     *   <li>either the {@link AsyncHandler#onStatusReceived(HttpResponseStatus)} returned {@link AsyncHandler.State#ABORT}</li>
     *   <li>or {@link AsyncHandler#onHeadersReceived(HttpHeaders)} returned {@link AsyncHandler.State#ABORT}</li>
     *   <li>response body was empty</li>
     * </ul>
     *
     * @return true if the response's body has been computed by an {@link AsyncHandler} to new empty bytes
     */
    boolean hasResponseBody();

    /**
     * Get the remote address that the client initiated the request to.
     *
     * @return The remote address that the client initiated the request to. May be {@code null} if asynchronous provider is unable to provide the remote address
     */
    SocketAddress getRemoteAddress();

    /**
     * Get the local address that the client initiated the request from.
     *
     * @return The local address that the client initiated the request from. May be {@code null} if asynchronous provider is unable to provide the local address
     */
    SocketAddress getLocalAddress();

    class ResponseBuilder {
        private final List<HttpResponseBodyPart> bodyParts = new ArrayList<>(1);
        private @Nullable HttpResponseStatus status;
        private @Nullable HttpHeaders headers;

        public void accumulate(HttpResponseStatus status) {
            this.status = status;
        }

        public void accumulate(HttpHeaders headers) {
            this.headers = this.headers == null ? headers : this.headers.add(headers);
        }

        /**
         * @param bodyPart a body part (possibly empty, but will be filtered out)
         */
        public void accumulate(HttpResponseBodyPart bodyPart) {
            if (bodyPart.length() > 0) {
                bodyParts.add(bodyPart);
            }
        }

        /**
         * Build a {@link Response} instance
         *
         * @return a {@link Response} instance
         */
        public @Nullable Response build() {
            return status == null ? null : new NettyResponse(status, headers, bodyParts);
        }

        /**
         * Reset the internal state of this builder.
         */
        public void reset() {
            bodyParts.clear();
            status = null;
            headers = null;
        }
    }
}