Class IQuery

  extended by ix.icore.IXAgent
      extended by ix.iquery.IQuery
Direct Known Subclasses:

public abstract class IQuery
extends IXAgent

Generic base for simple information source I-X agents. Such an agent is typically defined by subclassing both this class and LookupHandler and defining the three methods those classes leave abstract:

Here is an outline example in which an inner class is used for the LookupHandler subclass:
 public class Example extends IQuery {

     public Example() {

     public static void main(String[] argv) {
         Util.printGreeting("I-Q Example");
         new Example().mainStartup(argv);

     protected boolean isLookupActivity(Activity activity) {
         return activity.getPattern().get(0) == ...;

     protected LookupHandler
               makeLookupHandler(IQuery queryAgent,
                                 Activity lookupActivity) {
         return new ExampleLookupHandler(queryAgent, lookupActivity);

     static class ExampleLookupHandler extends LookupHandler {

         ExampleLookupHandler(IQuery queryAgent, Activity lookupActivity) {
             super(queryAgent, lookupActivity);

         protected void handleLookup() {
             try {
                 sendReport(ReportType.SUCCESS, "Finished -- ...");
             catch (Exception e) {
                            "Problem: " + Debug.describeException(e));



By default, IQuery provides only a simple GUI: a frame containing an "Exit" button and a text area used to display a transcript of the messages sent and received. A different GUI could be created by overriding the startup() or setupGUI() methods.

When the agent receives a message, a description of the message is added to the transcript text area. Then, if the message is an Activity and isLookupActivity(Activity) returns true, the handleLookupActivity(Activity) method is called.

That method arranges for each request to be handled in a separate IQuery.LookupThread. The thread creates a new LookupHandler by calling makeLookupHandler(IQuery, Activity) and then calls the handler's LookupHandler.handleLookup() method.

Most activities of an I-X agent take place in the AWT event-handling thread, and operations on Swing GUI components should take place there as well, so LookupHandler.handleLookup() has to take care to do things in the right thread. The LookupHandler class provides some utility methods that deal with the most common cases: adding text to the transcript, and sending a report back to the agent that sent the lookup activity. In other cases, Util.swingAndWait(Runnable) might be used. Debug.displayException(Throwable) can be used in any thread to put up a dialog window that tells the user of an exception.

If for some reason you don't want a separate thread for each request, override handleLookupActivity(Activity).

Nested Class Summary
protected  class IQuery.LookupThread
          A thread that invokes a LookupHandler.
Field Summary
Fields inherited from class ix.icore.IXAgent
contactManager, displayName, eventLogger, exitHooks, initialDisplayName, ipcName, ipcStrategyName, iSimTimer, mainAgent, nameListeners, startupDate, startupHooks, symbolName, textFrame
Constructor Summary
Method Summary
 void addTool(ToolController tc)
          Adds a tool, usually by adding an entry to a "Tools" menu in the GUI.
 void do_transcript(java.lang.String line)
          A utility that adds a line to this agent's transcript text area.
 void exit()
          Called when the agent should cease execution.
protected  void handleLookupActivity(Activity activity)
          Handles the activity be creating and starting a new IQuery.LookupThread.
 void handleNewActivity(Activity activity)
          Handles new activities from external sources.
protected abstract  boolean isLookupActivity(Activity activity)
          Determines whether the activity is one that should be handled by a LookupHandler.
protected abstract  LookupHandler makeLookupHandler(IQuery queryAgent, Activity lookupActivity)
          Return a LookupHandler for an activity that was approved by isLookupActivity(Activity).
protected  void processCommandLineArguments()
          Command-line argument processing.
protected  void setupGUI()
          Creates a "transcript" frame for this agent, including an "Exit" button.
protected  void startup()
          Agent setup and initialization.
Methods inherited from class ix.icore.IXAgent
addAgentNameListener, addExitHook, addStartupHook, adjustLookAndFeel, displayMessage, do_mainStartup, ensureTool, fireSymbolNameChanged, getAgent, getAgentDisplayName, getAgentIPCName, getAgentStartupDate, getAgentSymbolName, getContactManager, getEventLogger, getISimTimer, getKnownAgents, handleInput, handleNewChatMessage, handleNewConstraint, handleNewIssue, handleNewReport, handleReceivedReport, installAgentExtensions, installAgentExtensions, isMainAgent, log, mainStartup, notePossibleNewContact, pre_handleInput, preprocessInput, reportInputException, setAgentSymbolName, setEventLogger, setupISimTimer, startServer
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public IQuery()
Method Detail


protected void processCommandLineArguments()
Command-line argument processing.

processCommandLineArguments in class IXAgent
See Also:
IFUtil.adjustLookAndFeel(), IPC.makeCommunicationStrategy(String methodName), ContactManager.processCommandLineArguments(), Debug.on, Parameters


protected void startup()
Agent setup and initialization. The method supplied by the IQuery class just calls setupGUI() in the AWT event thread.

startup in class IXAgent
See Also:


protected void setupGUI()
Creates a "transcript" frame for this agent, including an "Exit" button.


public void exit()
Called when the agent should cease execution.

exit in class IXAgent


public void addTool(ToolController tc)
Description copied from class: IXAgent
Adds a tool, usually by adding an entry to a "Tools" menu in the GUI. This method throws an exception that says tool additions are not supported; it should be overridden in subclasses that do allow tools.

addTool in class IXAgent


public void do_transcript(java.lang.String line)
A utility that adds a line to this agent's transcript text area. This method is normally called by other utility methods, including ones in the LookupHandler class, rather than being called directly.


public void handleNewActivity(Activity activity)
Handles new activities from external sources. A description of the activity is added to the transcript text area. Then, if isLookupActivity(Activity) returns true, handleNewActivity calls handleLookupActivity(Activity); otherwise, the activity is ignored.

handleNewActivity in class IXAgent


protected void handleLookupActivity(Activity activity)
Handles the activity be creating and starting a new IQuery.LookupThread.


protected abstract boolean isLookupActivity(Activity activity)
Determines whether the activity is one that should be handled by a LookupHandler.

See Also:


protected abstract LookupHandler makeLookupHandler(IQuery queryAgent,
                                                   Activity lookupActivity)
Return a LookupHandler for an activity that was approved by isLookupActivity(Activity).