org.apache.http.impl.client.DefaultConnectionKeepAliveStrategy Maven / Gradle / Ivy

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 * to you under the Apache License, Version 2.0 (the
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package org.apache.http.impl.client;

import org.apache.http.HeaderElement;
import org.apache.http.HeaderElementIterator;
import org.apache.http.HttpResponse;
import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.conn.ConnectionKeepAliveStrategy;
import org.apache.http.message.BasicHeaderElementIterator;
import org.apache.http.protocol.HTTP;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.Args;

/**
 * Default implementation of a strategy deciding duration
 * that a connection can remain idle.
 *
 * The default implementation looks solely at the 'Keep-Alive'
 * header's timeout token.
 *
 * @since 4.0
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class DefaultConnectionKeepAliveStrategy implements ConnectionKeepAliveStrategy {

    public static final DefaultConnectionKeepAliveStrategy INSTANCE = new DefaultConnectionKeepAliveStrategy();

    @Override
    public long getKeepAliveDuration(final HttpResponse response, final HttpContext context) {
        Args.notNull(response, "HTTP response");
        final HeaderElementIterator it = new BasicHeaderElementIterator(
                response.headerIterator(HTTP.CONN_KEEP_ALIVE));
        while (it.hasNext()) {
            final HeaderElement he = it.nextElement();
            final String param = he.getName();
            final String value = he.getValue();
            if (value != null && param.equalsIgnoreCase("timeout")) {
                try {
                    return Long.parseLong(value) * 1000;
                } catch(final NumberFormatException ignore) {
                }
            }
        }
        return -1;
    }

}