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package org.apache.james.transport.matchers;

import org.apache.mailet.GenericMatcher;
import org.apache.mailet.Mail;

import java.util.Collection;

/**
 * use: <mailet match="HasHeader=<header>" class="..." />
 *
 * This matcher simply checks to see if the header named is present.
 * If complements the AddHeader mailet.
 *
 * TODO: support lists of headers and values, e.g, match="{<header>[=value]}+"
 *       [will require a complete rewrite from the current trivial one-liner]
 *
 */
public class HasHeader extends GenericMatcher {

    public Collection match(Mail mail) throws javax.mail.MessagingException {
        return (mail.getMessage().getHeader(getCondition(), null) != null) ? mail.getRecipients() : null;
    }
}