org.lastbamboo.common.stun.client.StunClientMessageVisitor Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of stun-client Show documentation
The newest version!
package org.lastbamboo.common.stun.client;

import org.littleshoot.stun.stack.message.BindingErrorResponse;
import org.littleshoot.stun.stack.message.BindingSuccessResponse;
import org.littleshoot.stun.stack.message.ConnectErrorStunMessage;
import org.littleshoot.stun.stack.message.StunMessage;
import org.littleshoot.stun.stack.message.StunMessageVisitorAdapter;
import org.littleshoot.stun.stack.transaction.StunClientTransaction;
import org.littleshoot.stun.stack.transaction.StunTransactionTracker;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A visitor for STUN messages on STUN clients. 
 * 
 * @param  The type the specific visitor returns.
 */
public class StunClientMessageVisitor extends StunMessageVisitorAdapter {

    private final Logger m_log = LoggerFactory.getLogger(getClass());
    protected final StunTransactionTracker m_transactionTracker;

    /**
     * Creates a new STUN client message visitor.
     * 
     * @param transactionTracker
     *            The class that keeps track of transactions.
     */
    public StunClientMessageVisitor(
            final StunTransactionTracker transactionTracker) {
        m_transactionTracker = transactionTracker;
    }

    @Override
    public T visitConnectErrorMesssage(final ConnectErrorStunMessage message) {
        if (m_log.isDebugEnabled()) {
            m_log.debug("Received ICMP error: {}", message);
        }
        return notifyTransaction(message);
    }

    @Override
    public T visitBindingErrorResponse(final BindingErrorResponse response) {
        if (m_log.isDebugEnabled()) {
            m_log.debug("Received Binding Error response: {}", response);
        }
        return notifyTransaction(response);
    }

    @Override
    public T visitBindingSuccessResponse(final BindingSuccessResponse response) {
        if (m_log.isDebugEnabled()) {
            m_log.debug("Received Binding Response: {}", response);
        }
        return notifyTransaction(response);
    }

    private T notifyTransaction(final StunMessage response) {
        final StunClientTransaction ct = 
            this.m_transactionTracker.getClientTransaction(response);
        m_log.debug("Accessed transaction: {}", ct);

        if (ct == null) {
            // This will happen fairly frequently with UDP because messages
            // are retransmitted in case any are lost. When responses are
            // received, the transaction ID is removed, so we won't recognize
            // the IDs of subsequent responses.
            m_log.debug("No matching transaction for response: {}", response);
            return null;
        }

        return response.accept(ct);
    }

}