main
Class DataGatherer

java.lang.Object
  main.DataGatherer

public class DataGatherer
extends java.lang.Object

The DataGatherer class serves as a connection to Sophia. Its methods allow to send queries to sophia and to retrieve the results. A query must be set before it is executed and a query must be executed before its result can be seen.

Nested Class Summary

(package private) class

DataGatherer.ReadLine

Field Summary

private java.lang.String	query
private java.lang.String	result
private int	timeout

Constructor Summary

DataGatherer()
Creates a new, uninitialized DataGatherer with a time-out value of 10 seconds.

DataGatherer(int timeout)
Creates a new, uninitialized DataGatherer with a specified time before a query times out.

Method Summary

void	executeQuery() Executes the query and stores the results.
void	executeQuery(int timeout) Executes the query and stores the results.
java.lang.String	getResult() Returns the results from Sophia from executing the query.
private java.lang.String	sendQuery(java.lang.String host, java.lang.String port, int timeout)
void	setQuery(java.lang.String query) Sets the Prolog query that will be sent to Sophia.
java.lang.String	toString() Returns a string representation of the DataGatherer.
private java.lang.String	tryHosts(int timeout)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

query

private java.lang.String query

result

private java.lang.String result

timeout

private int timeout

Constructor Detail

DataGatherer

public DataGatherer()

Creates a new, uninitialized DataGatherer with a time-out value of 10 seconds.

DataGatherer

public DataGatherer(int timeout)

Creates a new, uninitialized DataGatherer with a specified time before a query times out.

Parameters:

timeout - the time in seconds a query has before it times out

Method Detail

setQuery

public void setQuery(java.lang.String query)

Sets the Prolog query that will be sent to Sophia.

Parameters:

query - a String

executeQuery

public void executeQuery()
                  throws java.net.UnknownHostException,
                         java.io.IOException

Executes the query and stores the results. If the query times out, an exception will be thrown.

Throws:

java.net.UnknownHostException - the host is not accessible

java.io.IOException - an I/O error occurred

executeQuery

public void executeQuery(int timeout)
                  throws java.net.UnknownHostException,
                         java.io.IOException

Executes the query and stores the results. If the query times out as specified by the argument, an exception is thrown. The argument overrides the time-out value set by the constructor.

Parameters:

timeout - the time in seconds the query has before it times out

Throws:

java.net.UnknownHostException - if the host is not accessible

java.io.IOException - if an I/O error occurred

getResult

public java.lang.String getResult()

Returns the results from Sophia from executing the query.

Returns:

the query results

tryHosts

private java.lang.String tryHosts(int timeout)
                           throws java.net.UnknownHostException,
                                  java.io.IOException

Throws:

java.net.UnknownHostException

java.io.IOException

sendQuery

private java.lang.String sendQuery(java.lang.String host,
                                   java.lang.String port,
                                   int timeout)
                            throws java.io.IOException,
                                   java.net.UnknownHostException

Throws:

java.io.IOException

java.net.UnknownHostException

toString

public java.lang.String toString()

Returns a string representation of the DataGatherer.

Overrides:

toString in class java.lang.Object

Returns:

a string representation