org.asyncflows.protocol.http.server.util.ResponseUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of asyncflows-protocol-http Show documentation
This component contains implementation of HTTP 1.1 protocol.
There is a newer version: 0.1.1
Show newest version
/*
 * Copyright (c) 2018 Konstantin Plotnikov
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package org.asyncflows.protocol.http.server.util;

import org.asyncflows.io.AInput;
import org.asyncflows.io.IOUtil;
import org.asyncflows.io.util.CharIOUtil;
import org.asyncflows.protocol.http.common.HttpLimits;
import org.asyncflows.protocol.http.common.HttpStatusUtil;
import org.asyncflows.protocol.http.common.headers.HttpHeaders;
import org.asyncflows.protocol.http.common.headers.HttpHeadersUtil;
import org.asyncflows.protocol.http.server.HttpExchange;
import org.asyncflows.core.Promise;

import java.nio.ByteBuffer;

import static org.asyncflows.core.util.CoreFlowsSeq.aSeq;
import static org.asyncflows.core.util.CoreFlowsResource.aTry;

/**
 * The utility class that contains helper methods for responding.
 */
public final class ResponseUtil {
    /**
     * The private constructor for utility class.
     */
    private ResponseUtil() {
        // do nothing
    }

    /**
     * Do a short reply with the specified html text, the text is converted to an array of bytes encoded as UTF-8.
     * Use this method only for the short replies, for which creating an array would not cause a problem.
     *
     * @param exchange the message exchange
     * @param code     the code to reply with
     * @param reason   the reason text (ignored for HTML 2.0)
     * @param text     the body text
     * @return when replied
     */
    public static Promise shortReply(final HttpExchange exchange, final int code, final String reason,
                                           final String text) {
        return shortReply(exchange, code, reason, text, new HttpHeaders());
    }

    /**
     * Do a short reply with the specified html text, the text is converted to an array of bytes encoded as UTF-8.
     * Use this method only for the short replies, for which creating an array would not cause a problem.
     *
     * @param exchange the message exchange
     * @param code     the code to reply with
     * @param reason   the reason text (ignored for HTML 2.0)
     * @param text     the body text
     * @param headers  the headers
     * @return when replied
     */
    public static Promise shortReply(final HttpExchange exchange, final int code, final String reason,
                                           final String text, final HttpHeaders headers) {
        final byte[] data = text.getBytes(CharIOUtil.UTF8);
        headers.setHeader(HttpHeadersUtil.CONTENT_TYPE_HEADER, HttpHeadersUtil.CONTENT_TYPE_HTML_UTF8);
        return aTry(exchange.respond(code, reason, headers, (long) data.length)).run(
                output -> output.write(ByteBuffer.wrap(data)));
    }

    /**
     * Do a short reply with the specified html text, the text is converted to an array of bytes encoded as UTF-8.
     * Use this method only for the short replies, for which creating an array would not cause a problem.
     *
     * @param exchange the message exchange
     * @param code     the code to reply with
     * @param text     the body text
     * @param headers  the headers
     * @return when replied
     */
    public static Promise shortReply(final HttpExchange exchange, final int code,
                                           final String text, final HttpHeaders headers) {
        return shortReply(exchange, code, null, text, headers);
    }

    /**
     * Redirect to the page (relative path).
     *
     * @param exchange the exchange context
     * @param path     the relative path
     * @return when redirect finishes.
     */
    public static Promise redirect(final HttpExchange exchange, final String path) {
        final HttpHeaders headers = new HttpHeaders();
        headers.setHeader(HttpHeadersUtil.LOCATION_HEADER, exchange.getRequestUri().resolve(path).toString());
        return exchange.respond(HttpStatusUtil.TEMPORARY_REDIRECT, null, headers, 0L).toVoid();
    }

    /**
     * Discard input message content and close the stream.
     *
     * @param input the input
     * @return when finishes
     */
    public static Promise discardAndClose(final AInput input) {
        return aSeq(
                () -> IOUtil.BYTE.discard(input, ByteBuffer.allocate(HttpLimits.DEFAULT_BUFFER_SIZE)).toVoid()
        ).finallyDo(
                input::close
        );
    }
}