com.signalfx.shaded.jetty.client.api.ContentProvider Maven / Gradle / Ivy

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//  Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
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//  and Apache License v2.0 which accompanies this distribution.
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//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
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//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
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//  You may elect to redistribute this code under either of these licenses.
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package com.signalfx.shaded.jetty.client.api;

import java.io.Closeable;
import java.nio.ByteBuffer;
import java.util.Iterator;

import com.signalfx.shaded.jetty.client.HttpClient;
import com.signalfx.shaded.jetty.client.util.ByteBufferContentProvider;
import com.signalfx.shaded.jetty.client.util.PathContentProvider;

/**
 * {@link ContentProvider} provides a source of request content.
 * Implementations should return an {@link Iterator} over the request content.
 * If the request content comes from a source that needs to be closed (for
 * example, an {@link java.io.InputStream}), then the iterator implementation class
 * must implement {@link Closeable} and will be closed when the request is
 * completed (either successfully or failed).
 * Applications should rely on utility classes such as {@link ByteBufferContentProvider}
 * or {@link PathContentProvider}.
 * {@link ContentProvider} provides a {@link #getLength() length} of the content
 * it represents.
 * If the length is positive, it typically overrides any {@code Content-Length}
 * header set by applications; if the length is negative, it typically removes
 * any {@code Content-Length} header set by applications, resulting in chunked
 * content (i.e. {@code Transfer-Encoding: chunked}) being sent to the server.
 */
public interface ContentProvider extends Iterable
{
    /**
     * @return the content length, if known, or -1 if the content length is unknown
     */
    long getLength();

    /**
     * Whether this ContentProvider can produce exactly the same content more
     * than once.
     * Implementations should return {@code true} only if the content can be
     * produced more than once, which means that invocations to {@link #iterator()}
     * must return a new, independent, iterator instance over the content.
     * The {@link HttpClient} implementation may use this method in particular
     * cases where it detects that it is safe to retry a request that failed.
     *
     * @return whether the content can be produced more than once
     */
    default boolean isReproducible()
    {
        return false;
    }

    /**
     * An extension of {@link ContentProvider} that provides a content type string
     * to be used as a {@code Content-Type} HTTP header in requests.
     */
    interface Typed extends ContentProvider
    {
        /**
         * @return the content type string such as "application/octet-stream" or
         * "application/json;charset=UTF8", or null if no content type must be set
         */
        String getContentType();
    }
}