Mina Io监听器接口定义及抽象实现

Mina IoService接口定义及抽象实现：http://donald-draper.iteye.com/blog/2378271
引言:
    上面我们看了IoService接口的定义及抽象实现，先来回顾一下：
    抽象service关联一个IoHandler处理会话相关事件，关联一个执行器Executor，负责处理io事件的执行，一个会话配置IOsessionConfig，用于service创建会话时，配置会话，一个过滤链构建器IoFilterChainBuilder，用于构建会话的过滤链，会话数据结构工厂，用于创建会话的属性Map和写请求队列，还有service监听器和统计器。抽象service构造，首先检查会话配置和传输元数据，会话配置必须传输元数据的会话配置类型必须相同，即socket（TCP），会话配置为socketSessionConfig，报文通信（UDP），为DatagramSessionConfig；然后将会话创建监听器serviceActivationListener添加监听器管理器IoServiceListenerSupport；初始化会话配置，IO事件执行器executor和异常监视器。初始化会话就是将service会话数据结构工厂的会话属性添加到具体的会话中，将service会话数据结构工厂的写请求队列，设置到具体的会话中，如果是连接请求会话，则将连接结果添加会话属性中。
今天我们我们来看一下IoService的一个分支IoAcceptor：

/**
 * Accepts incoming connection, communicates with clients, and fires events to
 * {@link IoHandler}s.
 接收连接请求，与客户端通信，触发IoHandler相关事件。
 * <p>
 * Please refer to
 * [url=../../../../../xref-examples/org/apache/mina/examples/echoserver/Main.html]EchoServer[/url]
 * example.
 * <p>
 * You should bind to the desired socket address to accept incoming
 * connections, and then events for incoming connections will be sent to
 * the specified default {@link IoHandler}.
 * <p>
 你应该绑定socket地址，以接收连接请求，连接请求事件将会发送个默认的IoHandler。
 * Threads accept incoming connections start automatically when
 * {@link #bind()} is invoked, and stop when {@link #unbind()} is invoked.
 *当IoAcceptor绑定地址时，相关线程将自动开始接收连接请求，当调用#unbind方法，将停止
 线程接收连接请求
 * @author [url=http://mina.apache.org]Apache MINA Project[/url]
 */
public interface IoAcceptor extends IoService {
    /**
     * Returns the local address which is bound currently.  If more than one
     * address are bound, only one of them will be returned, but it's not
     * necessarily the firstly bound address.
     * 返回当前绑定本地地址，当绑定多个地址时，返回其中一个，不需要非是第一个绑定的地址
     * @return The bound LocalAddress
     */
    SocketAddress getLocalAddress();

    /**
     * Returns a {@link Set} of the local addresses which are bound currently.
     * 返回绑定的地址集
     * @return The Set of bound LocalAddresses
     */
    Set<SocketAddress> getLocalAddresses();

    /**
     * Returns the default local address to bind when no argument is specified
     * in {@link #bind()} method.  Please note that the default will not be
     * used if any local address is specified.  If more than one address are
     * set, only one of them will be returned, but it's not necessarily the
     * firstly specified address in {@link #setDefaultLocalAddresses(List)}.
     * 当bind无参方法被调用时，返回一个默认的本地地址。
     * @return The default bound LocalAddress
     */
    SocketAddress getDefaultLocalAddress();

    /**
     * Returns a {@link List} of the default local addresses to bind when no
     * argument is specified in {@link #bind()} method.  Please note that the
     * default will not be used if any local address is specified.
     * 返回默认地址集
     * @return The list of default bound LocalAddresses
     */
    List<SocketAddress> getDefaultLocalAddresses();

    /**
     * Sets the default local address to bind when no argument is specified in
     * {@link #bind()} method.  Please note that the default will not be used
     * if any local address is specified.
     *设置默认socket地址
     * @param localAddress The local addresses to bind the acceptor on
     */
    void setDefaultLocalAddress(SocketAddress localAddress);

    /**
     * Sets the default local addresses to bind when no argument is specified
     * in {@link #bind()} method.  Please note that the default will not be
     * used if any local address is specified.
     设置默认地址集
     * @param firstLocalAddress The first local address to bind the acceptor on
     * @param otherLocalAddresses The other local addresses to bind the acceptor on
     */
    void setDefaultLocalAddresses(SocketAddress firstLocalAddress, SocketAddress... otherLocalAddresses);

    /**
     * Sets the default local addresses to bind when no argument is specified
     * in {@link #bind()} method.  Please note that the default will not be
     * used if any local address is specified.
     * 
     * @param localAddresses The local addresses to bind the acceptor on
     */
    void setDefaultLocalAddresses(Iterable<? extends SocketAddress> localAddresses);

    /**
     * Sets the default local addresses to bind when no argument is specified
     * in {@link #bind()} method.  Please note that the default will not be
     * used if any local address is specified.
     * 
     * @param localAddresses The local addresses to bind the acceptor on
     */
    void setDefaultLocalAddresses(List<? extends SocketAddress> localAddresses);

    /**
     * Returns <tt>true</tt> if and only if all clients are closed when this
     * acceptor unbinds from all the related local address (i.e. when the
     * service is deactivated).
     当且仅当所有客户端关闭，acceptor解绑所有相关本地地址
     * 
     * @return <tt>true</tt> if the service sets the closeOnDeactivation flag
     */
    boolean isCloseOnDeactivation();

    /**
     * Sets whether all client sessions are closed when this acceptor unbinds
     * from all the related local addresses (i.e. when the service is
     * deactivated).  The default value is <tt>true</tt>.
     * 无论所有客户端关闭是否，acceptor是否解绑所有相关本地地址，设置closeOnDeactivation
     * @param closeOnDeactivation <tt>true</tt> if we should close on deactivation
     */
    void setCloseOnDeactivation(boolean closeOnDeactivation);

    /**
     * Binds to the default local address(es) and start to accept incoming
     * connections.
     *绑定默认的socket本地地址，接收连接请求
     * @throws IOException if failed to bind
     */
    void bind() throws IOException;

    /**
     * Binds to the specified local address and start to accept incoming
     * connections.
     *绑定socket本地地址，接收连接请求
     * @param localAddress The SocketAddress to bind to
     * 
     * @throws IOException if failed to bind
     */
    void bind(SocketAddress localAddress) throws IOException;

    /**
     * Binds to the specified local addresses and start to accept incoming
     * connections. If no address is given, bind on the default local address.
     * 绑定socket本地地址，接收连接请求，如果没给给定参数，绑定默认地址
     * @param firstLocalAddress The first address to bind to
     * @param addresses The SocketAddresses to bind to
     * 
     * @throws IOException if failed to bind
     */
    void bind(SocketAddress firstLocalAddress, SocketAddress... addresses) throws IOException;

    /**
     * Binds to the specified local addresses and start to accept incoming
     * connections. If no address is given, bind on the default local address.
     * 绑定socket本地地址，接收连接请求，如果没给给定参数，绑定默认地址
     * @param addresses The SocketAddresses to bind to
     *
     * @throws IOException if failed to bind
     */
    void bind(SocketAddress... addresses) throws IOException;

    /**
     * Binds to the specified local addresses and start to accept incoming
     * connections.
     *绑定socket本地地址，接收连接请求，如果没给给定参数，绑定默认地址
     * @param localAddresses The local address we will be bound to
     * @throws IOException if failed to bind
     */
    void bind(Iterable<? extends SocketAddress> localAddresses) throws IOException;

    /**
     * Unbinds from all local addresses that this service is bound to and stops
     * to accept incoming connections.  All managed connections will be closed
     * if {@link #setCloseOnDeactivation(boolean) disconnectOnUnbind} property
     * is <tt>true</tt>.  This method returns silently if no local address is
     * bound yet.
     解绑service绑定的所有本地socket地址，停止接收，连接请求。如果CloseOnDeactivation参数为
     解绑时，断开连接，则关闭service管理的所有会话。
     */
    void unbind();

    /**
     * Unbinds from the specified local address and stop to accept incoming
     * connections.  All managed connections will be closed if
     * {@link #setCloseOnDeactivation(boolean) disconnectOnUnbind} property is
     * <tt>true</tt>.  This method returns silently if the default local
     * address is not bound yet.
     * 解绑service绑定的所有本地socket地址，停止接收，连接请求。如果CloseOnDeactivation参数为
     解绑时，断开连接，则关闭service管理的所有会话。
     * @param localAddress The local address we will be unbound from
     */
    void unbind(SocketAddress localAddress);

    /**
     * Unbinds from the specified local addresses and stop to accept incoming
     * connections.  All managed connections will be closed if
     * {@link #setCloseOnDeactivation(boolean) disconnectOnUnbind} property is
     * <tt>true</tt>.  This method returns silently if the default local
     * addresses are not bound yet.
     * 解绑service绑定的所有本地socket地址，停止接收，连接请求。如果CloseOnDeactivation参数为
     解绑时，断开连接，则关闭service管理的所有会话。
     * @param firstLocalAddress The first local address to be unbound from
     * @param otherLocalAddresses The other local address to be unbound from
     */
    void unbind(SocketAddress firstLocalAddress, SocketAddress... otherLocalAddresses);

    /**
     * Unbinds from the specified local addresses and stop to accept incoming
     * connections.  All managed connections will be closed if
     * {@link #setCloseOnDeactivation(boolean) disconnectOnUnbind} property is
     * <tt>true</tt>.  This method returns silently if the default local
     * addresses are not bound yet.
     * 解绑service绑定的所有本地socket地址，停止接收，连接请求。如果CloseOnDeactivation参数为
     解绑时，断开连接，则关闭service管理的所有会话。
     * @param localAddresses The local address we will be unbound from
     */
    void unbind(Iterable<? extends SocketAddress> localAddresses);

    /**
     * (Optional) Returns an {@link IoSession} that is bound to the specified
     * <tt>localAddress</tt> and the specified <tt>remoteAddress</tt> which
     * reuses the local address that is already bound by this service.
     返回绑定本地地址和远端socket地址的会话，本地地址，service已绑定，并可以重用
     * <p>
     * This operation is optional.  Please throw {@link UnsupportedOperationException}
     * if the transport type doesn't support this operation.  This operation is
     * usually implemented for connectionless transport types.
     *操作时可选的，如果transport不支持此操作，则可抛出UnsupportedOperationException，
     此操作一般报文通信会实现
     * @param remoteAddress The remote address bound to the service
     * @param localAddress The local address the session will be bound to
     * @throws UnsupportedOperationException if this operation is not supported
     * @throws IllegalStateException if this service is not running.
     * @throws IllegalArgumentException if this service is not bound to the
     *                                  specified <tt>localAddress</tt>.
     * @return The session bound to the the given localAddress and remote address
     */
    IoSession newSession(SocketAddress remoteAddress, SocketAddress localAddress);
}

从IoAcceptor的接口定义可以看，IoAcceptor是将IoService添加了监听连接请求功能。
再来看抽象实现：

/**
 * A base implementation of {@link IoAcceptor}.
 *
 * @author [url=http://mina.apache.org]Apache MINA Project[/url]
 * @org.apache.xbean.XBean
 */
public abstract class AbstractIoAcceptor extends AbstractIoService implements IoAcceptor {
    private final List<SocketAddress> defaultLocalAddresses = new ArrayList<>();//默认绑定的socket地址集
    private final List<SocketAddress> unmodifiableDefaultLocalAddresses = Collections
            .unmodifiableList(defaultLocalAddresses);//包装默认的地址集为不可修改集合
    private final Set<SocketAddress> boundAddresses = new HashSet<>();//绑定地址集
    private boolean disconnectOnUnbind = true;
    /**
     * The lock object which is acquired while bind or unbind operation is performed.
     * Acquire this lock in your property setters which shouldn't be changed while
     * the service is bound.
     */
    protected final Object bindLock = new Object();
    
    /**
     * Constructor for {@link AbstractIoAcceptor}. You need to provide a default
     * session configuration and an {@link Executor} for handling I/O events. If
     * null {@link Executor} is provided, a default one will be created using
     * {@link Executors#newCachedThreadPool()}.
     * 根据会话配置和执行器构造抽象Io接收器
     * @see AbstractIoService#AbstractIoService(IoSessionConfig, Executor)
     * 
     * @param sessionConfig
     *            the default configuration for the managed {@link IoSession}
     * @param executor
     *            the {@link Executor} used for handling execution of I/O
     *            events. Can be <code>null</code>.
     */
    protected AbstractIoAcceptor(IoSessionConfig sessionConfig, Executor executor) {
        super(sessionConfig, executor);
        defaultLocalAddresses.add(null);
    }
}

来看一下地址绑定操作：

  /**
     * {@inheritDoc}
     */
    @Override
    public final void bind() throws IOException {
        bind(getDefaultLocalAddresses());
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final void bind(SocketAddress localAddress) throws IOException {
        if (localAddress == null) {
            throw new IllegalArgumentException("localAddress");
        }
        
        List<SocketAddress> localAddresses = new ArrayList<>(1);
        localAddresses.add(localAddress);
        bind(localAddresses);
    }
    /**
     * {@inheritDoc}
     */
    @Override
    public final void bind(SocketAddress... addresses) throws IOException {
        if ((addresses == null) || (addresses.length == 0)) {
            bind(getDefaultLocalAddresses());
            return;
        }
        List<SocketAddress> localAddresses = new ArrayList<>(2);

        for (SocketAddress address : addresses) {
            localAddresses.add(address);
        }
        bind(localAddresses);
    }
    /**
     * {@inheritDoc}
     */
    @Override
    public final void bind(SocketAddress firstLocalAddress, SocketAddress... addresses) throws IOException {
        if (firstLocalAddress == null) {
            bind(getDefaultLocalAddresses());
        }
        if ((addresses == null) || (addresses.length == 0)) {
            bind(getDefaultLocalAddresses());
            return;
        }
        List<SocketAddress> localAddresses = new ArrayList<>(2);
        localAddresses.add(firstLocalAddress);

        for (SocketAddress address : addresses) {
            localAddresses.add(address);
        }
        bind(localAddresses);
    }
以上的绑定方法，实际由bind(Iterable<? extends SocketAddress> localAddresses)完成。

    /**
     * {@inheritDoc}
     */
    @Override
public final void bind(Iterable<? extends SocketAddress> localAddresses) throws IOException {
        if (isDisposing()) {
            throw new IllegalStateException("The Accpetor disposed is being disposed.");
        }
        if (localAddresses == null) {
            throw new IllegalArgumentException("localAddresses");
        }
        List<SocketAddress> localAddressesCopy = new ArrayList<>();
        for (SocketAddress a : localAddresses) {
            checkAddressType(a);//检查地址类
            localAddressesCopy.add(a);
        }
        if (localAddressesCopy.isEmpty()) {
            throw new IllegalArgumentException("localAddresses is empty.");
        }
        boolean activate = false;
	//同步绑定锁和地址绑定集合
        synchronized (bindLock) {
            synchronized (boundAddresses) {
                if (boundAddresses.isEmpty()) {
                    activate = true;
                }
            }
            if (getHandler() == null) {
                throw new IllegalStateException("handler is not set.");
            }
            try {
	        //完成实际绑定
                Set<SocketAddress> addresses = bindInternal(localAddressesCopy);
                synchronized (boundAddresses) {
		   //将绑定地址添加到绑定集合boundAddresses
                    boundAddresses.addAll(addresses);
                }
            } catch (IOException | RuntimeException e) {
                throw e;
            } catch (Exception e) {
                throw new RuntimeIoException("Failed to bind to: " + getLocalAddresses(), e);
            }
        }
        if (activate) {
	   //通知Service监听器，Service已激活
            getListeners().fireServiceActivated();
        }
    }

绑定方法有以下几点要看

 1.
  checkAddressType(a);//检查地址类

 private void checkAddressType(SocketAddress a) {
       //检查绑定的socket地址与传输元数据的地址类型是否相同
        if (a != null && !getTransportMetadata().getAddressType().isAssignableFrom(a.getClass())) {
            throw new IllegalArgumentException("localAddress type: " + a.getClass().getSimpleName() + " (expected: "
                    + getTransportMetadata().getAddressType().getSimpleName() + ")");
        }
    }

 2.
 //完成实际绑定
 Set<SocketAddress> addresses = bindInternal(localAddressesCopy); 

/**
     * Starts the acceptor, and register the given addresses
     * 待子类扩展，启动监听器，注册地址
     * @param localAddresses The address to bind to
     * @return the {@link Set} of the local addresses which is bound actually
     * @throws Exception If the bind failed
     */
protected abstract Set<SocketAddress> bindInternal(List<? extends SocketAddress> localAddresses) throws Exception;

从上面可以看出，绑定地址首先要检查绑定的socket地址与传输元数据的地址类型是否相同，相同则通过bindInternal完成实际的绑定，然后通知Service监听器，Service已激活fireServiceActivated。
再来看地址解绑：

/**
     * {@inheritDoc}
     */
    @Override
    public final void unbind() {
        unbind(getLocalAddresses());
    }
    /**
     * {@inheritDoc}
     */
    @Override
    public final void unbind(SocketAddress localAddress) {
        if (localAddress == null) {
            throw new IllegalArgumentException("localAddress");
        }

        List<SocketAddress> localAddresses = new ArrayList<>(1);
        localAddresses.add(localAddress);
        unbind(localAddresses);
    }
    /**
     * {@inheritDoc}
     */
    @Override
    public final void unbind(SocketAddress firstLocalAddress, SocketAddress... otherLocalAddresses) {
        if (firstLocalAddress == null) {
            throw new IllegalArgumentException("firstLocalAddress");
        }
        if (otherLocalAddresses == null) {
            throw new IllegalArgumentException("otherLocalAddresses");
        }

        List<SocketAddress> localAddresses = new ArrayList<>();
        localAddresses.add(firstLocalAddress);
        Collections.addAll(localAddresses, otherLocalAddresses);
        unbind(localAddresses);
    }

上面所有的解绑方法实际通过unbind(Iterable<? extends SocketAddress> localAddresses)方法完成：
  

 /**
     * {@inheritDoc}
     */
    @Override
    public final void unbind(Iterable<? extends SocketAddress> localAddresses) {
        if (localAddresses == null) {
            throw new IllegalArgumentException("localAddresses");
        }
        boolean deactivate = false;
	//同步绑定锁和绑定地址集合
        synchronized (bindLock) {
            synchronized (boundAddresses) {
                if (boundAddresses.isEmpty()) {
                    return;
                }
                List<SocketAddress> localAddressesCopy = new ArrayList<>();
                int specifiedAddressCount = 0;
                for (SocketAddress a : localAddresses) {
                    specifiedAddressCount++;

                    if ((a != null) && boundAddresses.contains(a)) {
                        localAddressesCopy.add(a);
                    }
                }
                if (specifiedAddressCount == 0) {
                    throw new IllegalArgumentException("localAddresses is empty.");
                }
                if (!localAddressesCopy.isEmpty()) {
                    try {
                        unbind0(localAddressesCopy);
                    } catch (RuntimeException e) {
                        throw e;
                    } catch (Exception e) {
                        throw new RuntimeIoException("Failed to unbind from: " + getLocalAddresses(), e);
                    }
		    //清空绑定地址集合
                    boundAddresses.removeAll(localAddressesCopy);
                    if (boundAddresses.isEmpty()) {
                        deactivate = true;
                    }
                }
            }
        }
        if (deactivate) {
	    //触发Service监听器无效事件
            getListeners().fireServiceDeactivated();
        }
    }

/**
 * Implement this method to perform the actual unbind operation.
 * 待子类实现，具体解绑
 * @param localAddresses The address to unbind from
 * @throws Exception If the unbind failed
 */
protected abstract void unbind0(List<? extends SocketAddress> localAddresses) throws Exception;

从解绑地址方法来看，主要是委托unbind0方法完成实际解绑工作，清空绑定地址集合boundAddresses，触发Service监听器无效事件fireServiceDeactivated。
再来看其他方法，下面这些方法就不讲了，都是set和get操作看看就行：

  /**
     * {@inheritDoc}
     */
    @Override
    public SocketAddress getLocalAddress() {
        Set<SocketAddress> localAddresses = getLocalAddresses();
        if (localAddresses.isEmpty()) {
            return null;
        }

        return localAddresses.iterator().next();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final Set<SocketAddress> getLocalAddresses() {
        Set<SocketAddress> localAddresses = new HashSet<>();

        synchronized (boundAddresses) {
            localAddresses.addAll(boundAddresses);
        }

        return localAddresses;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public SocketAddress getDefaultLocalAddress() {
        if (defaultLocalAddresses.isEmpty()) {
            return null;
        }
        return defaultLocalAddresses.iterator().next();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final void setDefaultLocalAddress(SocketAddress localAddress) {
        setDefaultLocalAddresses(localAddress);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final List<SocketAddress> getDefaultLocalAddresses() {
        return unmodifiableDefaultLocalAddresses;
    }

    /**
     * {@inheritDoc}
     * @org.apache.xbean.Property nestedType="java.net.SocketAddress"
     */
    @Override
    public final void setDefaultLocalAddresses(List<? extends SocketAddress> localAddresses) {
        if (localAddresses == null) {
            throw new IllegalArgumentException("localAddresses");
        }
        setDefaultLocalAddresses((Iterable<? extends SocketAddress>) localAddresses);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final void setDefaultLocalAddresses(Iterable<? extends SocketAddress> localAddresses) {
        if (localAddresses == null) {
            throw new IllegalArgumentException("localAddresses");
        }

        synchronized (bindLock) {
            synchronized (boundAddresses) {
                if (!boundAddresses.isEmpty()) {
                    throw new IllegalStateException("localAddress can't be set while the acceptor is bound.");
                }

                Collection<SocketAddress> newLocalAddresses = new ArrayList<>();

                for (SocketAddress a : localAddresses) {
                    checkAddressType(a);
                    newLocalAddresses.add(a);
                }

                if (newLocalAddresses.isEmpty()) {
                    throw new IllegalArgumentException("empty localAddresses");
                }

                this.defaultLocalAddresses.clear();
                this.defaultLocalAddresses.addAll(newLocalAddresses);
            }
        }
    }

    /**
     * {@inheritDoc}
     * @org.apache.xbean.Property nestedType="java.net.SocketAddress"
     */
    @Override
    public final void setDefaultLocalAddresses(SocketAddress firstLocalAddress, SocketAddress... otherLocalAddresses) {
        if (otherLocalAddresses == null) {
            otherLocalAddresses = new SocketAddress[0];
        }

        Collection<SocketAddress> newLocalAddresses = new ArrayList<>(otherLocalAddresses.length + 1);

        newLocalAddresses.add(firstLocalAddress);
        
        for (SocketAddress a : otherLocalAddresses) {
            newLocalAddresses.add(a);
        }

        setDefaultLocalAddresses(newLocalAddresses);
    }
    /**
     * {@inheritDoc}
     */
    @Override
    public final boolean isCloseOnDeactivation() {
        return disconnectOnUnbind;
    }
    /**
     * {@inheritDoc}
     */
    @Override
    public final void setCloseOnDeactivation(boolean disconnectClientsOnUnbind) {
        this.disconnectOnUnbind = disconnectClientsOnUnbind;
    }

 

  /**
     * A {@Link IoFuture} 
     监听操作结果
     */
    public static class AcceptorOperationFuture extends ServiceOperationFuture {
        private final List<SocketAddress> localAddresses;

        /**
         * Creates a new AcceptorOperationFuture instance
         * 
         * @param localAddresses The list of local addresses to listen to
         */
        public AcceptorOperationFuture(List<? extends SocketAddress> localAddresses) {
            this.localAddresses = new ArrayList<>(localAddresses);
        }
        /**
         * @return The list of local addresses we listen to
         */
        public final List<SocketAddress> getLocalAddresses() {
            return Collections.unmodifiableList(localAddresses);
        }
        /**
         * @see Object#toString()
         */
        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();

            sb.append("Acceptor operation : ");

            if (localAddresses != null) {
                boolean isFirst = true;

                for (SocketAddress address : localAddresses) {
                    if (isFirst) {
                        isFirst = false;
                    } else {
                        sb.append(", ");
                    }

                    sb.append(address);
                }
            }
            return sb.toString();
        }
    }
}

总结；
IoAcceptor与IoService不同的是，添加了监听连接请求和地址绑定功能。抽象Io监听器AbstractIoAcceptor绑定地址首先要检查绑定的socket地址与传输元数据的地址类型是否相同，相同则通过bindInternal完成实际的绑定，然后通知Service监听器，Service已激活fireServiceActivated。解绑地址方法，主要是委托unbind0方法完成实际解绑工作，清空绑定地址集合boundAddresses，触发Service监听器无效事件fireServiceDeactivated。