Package org.apache.mina.core.session

Interface IoSession

  • All Known Subinterfaces:
    SerialSession
    All Known Implementing Classes:
    AbstractIoSession, AprSession, DummySession, NioSession, ProtocolCodecSession
    public interface IoSession

    A handle which represents connection between two end-points regardless of transport types.

    IoSession provides user-defined attributes. User-defined attributes are application-specific data which are associated with a session. It often contains objects that represents the state of a higher-level protocol and becomes a way to exchange data between filters and handlers.

    Adjusting Transport Type Specific Properties

    You can simply downcast the session to an appropriate subclass.

    Thread Safety

    IoSession is thread-safe. But please note that performing more than one write(Object) calls at the same time will cause the IoFilter.filterWrite(IoFilter.NextFilter,IoSession,WriteRequest) to be executed simultaneously, and therefore you have to make sure the IoFilter implementations you're using are thread-safe, too.

    Equality of Sessions

    TODO : The getId() method is totally wrong. We can't base a method which is designed to create a unique ID on the hashCode method. Object.equals(Object) and Object.hashCode() shall not be overriden to the default behavior that is defined in Object.
    Author:
    Apache MINA Project

    • Method Detail

      • getId

        long getId()
        Returns:
        a unique identifier for this session. Every session has its own ID which is different from each other. TODO : The way it's implemented does not guarantee that the contract is respected. It uses the HashCode() method which don't guarantee the key unicity.

      • getService

        IoService getService()
        Returns:
        the IoService which provides I/O service to this session.

      • getConfig

        IoSessionConfig getConfig()
        Returns:
        the configuration of this session.

      • getFilterChain

        IoFilterChain getFilterChain()
        Returns:
        the filter chain that only affects this session.

      • getWriteRequestQueue

        WriteRequestQueue getWriteRequestQueue()
        Get the queue that contains the message waiting for being written. As the reader might not be ready, it's frequent that the messages aren't written completely, or that some older messages are waiting to be written when a new message arrives. This queue is used to manage the backlog of messages.
        Returns:
        The queue containing the pending messages.

      • read

        ReadFuture read()
        TODO This javadoc is wrong. The return tag should be short.
        Returns:
        a ReadFuture which is notified when a new message is received, the connection is closed or an exception is caught. This operation is especially useful when you implement a client application. TODO : Describe here how we enable this feature. However, please note that this operation is disabled by default and throw IllegalStateException because all received events must be queued somewhere to support this operation, possibly leading to memory leak. This means you have to keep calling read() once you enabled this operation. To enable this operation, please call IoSessionConfig.setUseReadOperation(boolean) with true.
        Throws:
        IllegalStateException - if useReadOperation option has not been enabled.

      • write

        WriteFuture write​(Object message)
        Writes the specified message to remote peer. This operation is asynchronous; IoHandler.messageSent(IoSession,Object) will be invoked when the message is actually sent to remote peer. You can also wait for the returned WriteFuture if you want to wait for the message actually written.
        Parameters:
        message - The message to write
        Returns:
        The associated WriteFuture

      • write

        WriteFuture write​(Object message,
                  SocketAddress destination)
        (Optional) Writes the specified message to the specified destination. This operation is asynchronous; IoHandler.messageSent(IoSession, Object) will be invoked when the message is actually sent to remote peer. You can also wait for the returned WriteFuture if you want to wait for the message actually written.

        When you implement a client that receives a broadcast message from a server such as DHCP server, the client might need to send a response message for the broadcast message the server sent. Because the remote address of the session is not the address of the server in case of broadcasting, there should be a way to specify the destination when you write the response message. This interface provides write(Object, SocketAddress) method so you can specify the destination.

        Parameters:
        message - The message to write
        destination - null if you want the message sent to the default remote address
        Returns:
        The associated WriteFuture

      • close

        @Deprecated
CloseFuture close​(boolean immediately)
        Deprecated.
        Use either the closeNow() or the closeOnFlush() methods
        Closes this session immediately or after all queued write requests are flushed. This operation is asynchronous. Wait for the returned CloseFuture if you want to wait for the session actually closed.
        Parameters:
        immediately - true to close this session immediately . The pending write requests will simply be discarded. false to close this session after all queued write requests are flushed.
        Returns:
        The associated CloseFuture

      • closeNow

        CloseFuture closeNow()
        Closes this session immediately. This operation is asynchronous, it returns a CloseFuture.
        Returns:
        The CloseFuture that can be use to wait for the completion of this operation

      • closeOnFlush

        CloseFuture closeOnFlush()
        Closes this session after all queued write requests are flushed. This operation is asynchronous. Wait for the returned CloseFuture if you want to wait for the session actually closed.
        Returns:
        The associated CloseFuture

      • close

        @Deprecated
CloseFuture close()
        Deprecated.
        use closeNow()
        Closes this session after all queued write requests are flushed. This operation is asynchronous. Wait for the returned CloseFuture if you want to wait for the session actually closed.
        Returns:
        The associated CloseFuture

      • getAttachment

        @Deprecated
Object getAttachment()
        Deprecated.
        Use getAttribute(Object) instead.
        Returns an attachment of this session. This method is identical with getAttribute( "" ).
        Returns:
        The attachment

      • setAttachment

        @Deprecated
Object setAttachment​(Object attachment)
        Deprecated.
        Use setAttribute(Object, Object) instead.
        Sets an attachment of this session. This method is identical with setAttribute( "", attachment ).
        Parameters:
        attachment - The attachment
        Returns:
        Old attachment. null if it is new.

      • getAttribute

        Object getAttribute​(Object key)
        Returns the value of the user-defined attribute of this session.
        Parameters:
        key - the key of the attribute
        Returns:
        null if there is no attribute with the specified key

      • getAttribute

        Object getAttribute​(Object key,
                    Object defaultValue)
        Returns the value of user defined attribute associated with the specified key. If there's no such attribute, the specified default value is associated with the specified key, and the default value is returned. This method is same with the following code except that the operation is performed atomically. 
         if (containsAttribute(key)) {
     return getAttribute(key);
 } else {
     setAttribute(key, defaultValue);
     return defaultValue;
 }
        Parameters:
        key - the key of the attribute we want to retreive
        defaultValue - the default value of the attribute
        Returns:
        The retrieved attribute or null if not found

      • setAttribute

        Object setAttribute​(Object key,
                    Object value)
        Sets a user-defined attribute.
        Parameters:
        key - the key of the attribute
        value - the value of the attribute
        Returns:
        The old value of the attribute. null if it is new.

      • setAttribute

        Object setAttribute​(Object key)
        Sets a user defined attribute without a value. This is useful when you just want to put a 'mark' attribute. Its value is set to Boolean.TRUE.
        Parameters:
        key - the key of the attribute
        Returns:
        The old value of the attribute. null if it is new.

      • setAttributeIfAbsent

        Object setAttributeIfAbsent​(Object key,
                            Object value)
        Sets a user defined attribute if the attribute with the specified key is not set yet. This method is same with the following code except that the operation is performed atomically. 
         if (containsAttribute(key)) {
     return getAttribute(key);
 } else {
     return setAttribute(key, value);
 }
        Parameters:
        key - The key of the attribute we want to set
        value - The value we want to set
        Returns:
        The old value of the attribute. null if not found.

      • setAttributeIfAbsent

        Object setAttributeIfAbsent​(Object key)
        Sets a user defined attribute without a value if the attribute with the specified key is not set yet. This is useful when you just want to put a 'mark' attribute. Its value is set to Boolean.TRUE. This method is same with the following code except that the operation is performed atomically. 
         if (containsAttribute(key)) {
     return getAttribute(key);  // might not always be Boolean.TRUE.
 } else {
     return setAttribute(key);
 }
        Parameters:
        key - The key of the attribute we want to set
        Returns:
        The old value of the attribute. null if not found.

      • removeAttribute

        Object removeAttribute​(Object key)
        Removes a user-defined attribute with the specified key.
        Parameters:
        key - The key of the attribute we want to remove
        Returns:
        The old value of the attribute. null if not found.

      • removeAttribute

        boolean removeAttribute​(Object key,
                        Object value)
        Removes a user defined attribute with the specified key if the current attribute value is equal to the specified value. This method is same with the following code except that the operation is performed atomically. 
         if (containsAttribute(key) && getAttribute(key).equals(value)) {
     removeAttribute(key);
     return true;
 } else {
     return false;
 }
        Parameters:
        key - The key we want to remove
        value - The value we want to remove
        Returns:
        true if the removal was successful

      • replaceAttribute

        boolean replaceAttribute​(Object key,
                         Object oldValue,
                         Object newValue)
        Replaces a user defined attribute with the specified key if the value of the attribute is equals to the specified old value. This method is same with the following code except that the operation is performed atomically. 
         if (containsAttribute(key) && getAttribute(key).equals(oldValue)) {
     setAttribute(key, newValue);
     return true;
 } else {
     return false;
 }
        Parameters:
        key - The key we want to replace
        oldValue - The previous value
        newValue - The new value
        Returns:
        true if the replacement was successful

      • containsAttribute

        boolean containsAttribute​(Object key)
        Parameters:
        key - The key of the attribute we are looking for in the session
        Returns:
        true if this session contains the attribute with the specified key.

      • getAttributeKeys

        Set<Object> getAttributeKeys()
        Returns:
        the set of keys of all user-defined attributes.

      • isConnected

        boolean isConnected()
        Returns:
        true if this session is connected with remote peer.

      • isActive

        boolean isActive()
        Returns:
        true if this session is active.

      • isClosing

        boolean isClosing()
        Returns:
        true if and only if this session is being closed (but not disconnected yet) or is closed.

      • isSecured

        boolean isSecured()
        Returns:
        true if the session has started and initialized a SSLEngine, false if the session is not yet secured (the handshake is not completed) or if SSL is not set for this session, or if SSL is not even an option.

      • isServer

        boolean isServer()
        Returns:
        true if the session was created by an acceptor.

      • getCloseFuture

        CloseFuture getCloseFuture()
        Returns:
        the CloseFuture of this session. This method returns the same instance whenever user calls it.

      • getRemoteAddress

        SocketAddress getRemoteAddress()
        Returns:
        the socket address of remote peer.

      • getLocalAddress

        SocketAddress getLocalAddress()
        Returns:
        the socket address of local machine which is associated with this session.

      • setCurrentWriteRequest

        void setCurrentWriteRequest​(WriteRequest currentWriteRequest)
        Associate the current write request with the session
        Parameters:
        currentWriteRequest - the current write request to associate

      • suspendRead

        void suspendRead()
        Suspends read operations for this session.

      • suspendWrite

        void suspendWrite()
        Suspends write operations for this session.

      • resumeRead

        void resumeRead()
        Resumes read operations for this session.

      • resumeWrite

        void resumeWrite()
        Resumes write operations for this session.

      • isReadSuspended

        boolean isReadSuspended()
        Is read operation is suspended for this session.
        Returns:
        true if suspended

      • isWriteSuspended

        boolean isWriteSuspended()
        Is write operation is suspended for this session.
        Returns:
        true if suspended

      • updateThroughput

        void updateThroughput​(long currentTime,
                      boolean force)
        Update all statistical properties related with throughput assuming the specified time is the current time. By default this method returns silently without updating the throughput properties if they were calculated already within last calculation interval. If, however, force is specified as true, this method updates the throughput properties immediately.
        Parameters:
        currentTime - the current time in milliseconds
        force - Force the update if true

      • getReadBytes

        long getReadBytes()
        Returns:
        the total number of bytes which were read from this session.

      • getWrittenBytes

        long getWrittenBytes()
        Returns:
        the total number of bytes which were written to this session.

      • getReadMessages

        long getReadMessages()
        Returns:
        the total number of messages which were read and decoded from this session.

      • getWrittenMessages

        long getWrittenMessages()
        Returns:
        the total number of messages which were written and encoded by this session.

      • getReadBytesThroughput

        double getReadBytesThroughput()
        Returns:
        the number of read bytes per second.

      • getWrittenBytesThroughput

        double getWrittenBytesThroughput()
        Returns:
        the number of written bytes per second.

      • getReadMessagesThroughput

        double getReadMessagesThroughput()
        Returns:
        the number of read messages per second.

      • getWrittenMessagesThroughput

        double getWrittenMessagesThroughput()
        Returns:
        the number of written messages per second.

      • getScheduledWriteMessages

        int getScheduledWriteMessages()
        Returns:
        the number of messages which are scheduled to be written to this session.

      • getScheduledWriteBytes

        long getScheduledWriteBytes()
        Returns:
        the number of bytes which are scheduled to be written to this session.

      • getCurrentWriteMessage

        Object getCurrentWriteMessage()
        Returns the message which is being written by IoService.
        Returns:
        null if and if only no message is being written

      • getCurrentWriteRequest

        WriteRequest getCurrentWriteRequest()
        Returns the WriteRequest which is being processed by IoService.
        Returns:
        null if and if only no message is being written

      • getCreationTime

        long getCreationTime()
        Returns:
        the session's creation time in milliseconds

      • getLastIoTime

        long getLastIoTime()
        Returns:
        the time in millis when I/O occurred lastly.

      • getLastReadTime

        long getLastReadTime()
        Returns:
        the time in millis when read operation occurred lastly.

      • getLastWriteTime

        long getLastWriteTime()
        Returns:
        the time in millis when write operation occurred lastly.

      • isIdle

        boolean isIdle​(IdleStatus status)
        Parameters:
        status - The researched idle status
        Returns:
        true if this session is idle for the specified IdleStatus.

      • getIdleCount

        int getIdleCount​(IdleStatus status)
        Parameters:
        status - The researched idle status
        Returns:
        the number of the fired continuous sessionIdle events for the specified IdleStatus.

        If sessionIdle event is fired first after some time after I/O, idleCount becomes 1. idleCount resets to 0 if any I/O occurs again, otherwise it increases to 2 and so on if sessionIdle event is fired again without any I/O between two (or more) sessionIdle events.

      • getLastIdleTime

        long getLastIdleTime​(IdleStatus status)
        Parameters:
        status - The researched idle status
        Returns:
        the time in milliseconds when the last sessionIdle event is fired for the specified IdleStatus.