Explicitly updates the {@link #getLastAccessTime() lastAccessTime} of this session to the current time when
      this method is invoked.  This method can be used to ensure a session does not time out.
      <p/>
      Most programmers won't use this method directly and will instead rely on the last access time to be updated
      automatically as a result of an incoming web request or remote procedure call/method invocation.
      <p/>
      However, this method is particularly useful when supporting rich-client applications such as
      Java Web Start appp, Java or Flash applets, etc.  Although rare, it is possible in a rich-client
      environment that a user continuously interacts with the client-side application without a
      server-side method call ever being invoked.  If this happens over a long enough period of
      time, the user's server-side session could time-out.  Again, such cases are rare since most
      rich-clients frequently require server-side method invocations.
      <p/>
      In this example though, the user's session might still be considered valid because
      the user is actively &quot;using&quot; the application, just not communicating with the
      server. But because no server-side method calls are invoked, there is no way for the server
      to know if the user is sitting idle or not, so it must assume so to maintain session
      integrity.  This {@code touch()} method could be invoked by the rich-client application code during those
      times to ensure that the next time a server-side method is invoked, the invocation will not
      throw an {@link ExpiredSessionException ExpiredSessionException}.  In short terms, it could be used periodically
      to ensure a session does not time out.
      <p/>
      How often this rich-client &quot;maintenance&quot; might occur is entirely dependent upon
      the application and would be based on variables such as session timeout configuration,
      usage characteristics of the client application, network utilization and application server
      performance.
     
      @throws InvalidSessionException if this session has stopped or expired prior to calling this method.

做个记录


Joyven
630 声望34 粉丝

不学无(用之)术,不安于现状,总想鼓捣点什么,或者总想尝试一些什么新鲜事物。


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