/*
* Copyright 2006 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.felix.examples.dictionaryclient;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.apache.felix.examples.dictionaryservice.DictionaryService;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
/**
* This class implements a bundle that uses a dictionary service to check for
* the proper spelling of a word by check for its existence in the dictionary.
* This bundle uses the first service that it finds and does not monitor the
* dynamic availability of the service (i.e., it does not listen for the arrival
* or departure of dictionary services). When starting this bundle, the thread
* calling the start() method is used to read words from standard input. You can
* stop checking words by entering an empty line, but to start checking words
* again you must stop and then restart the bundle.
*
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
public class Activator implements BundleActivator
{
/**
* Implements BundleActivator.start(). Queries for all available dictionary
* services. If none are found it simply prints a message and returns,
* otherwise it reads words from standard input and checks for their
* existence from the first dictionary that it finds. (NOTE: It is very bad
* practice to use the calling thread to perform a lengthy process like
* this; this is only done for the purpose of the tutorial.)
*
* @param context the framework context for the bundle.
*/
public void start( BundleContext context ) throws Exception
{
// Query for all service references matching any language.
ServiceReference[] refs = context.getServiceReferences( DictionaryService.class.getName(), "(Language=*)" );
if ( refs != null )
{
try
{
System.out.println( "Enter a blank line to exit." );
BufferedReader in = new BufferedReader( new InputStreamReader( System.in ) );
String word = "";
// Loop endlessly.
while ( true )
{
// Ask the user to enter a word.
System.out.print( "Enter word: " );
word = in.readLine();
// If the user entered a blank line, then
// exit the loop.
if ( word.length() == 0 )
{
break;
}
// First, get a dictionary service and then check
// if the word is correct.
DictionaryService dictionary = ( DictionaryService ) context.getService( refs[0] );
if ( dictionary.checkWord( word ) )
{
System.out.println( "Correct." );
}
else
{
System.out.println( "Incorrect." );
}
// Unget the dictionary service.
context.ungetService( refs[0] );
}
}
catch ( IOException ex )
{
}
}
else
{
System.out.println( "Couldn't find any dictionary service..." );
}
}
/**
* Implements BundleActivator.stop(). Does nothing since the framework will
* automatically unget any used services.
*
* @param context the framework context for the bundle.
*/
public void stop( BundleContext context )
{
// NOTE: The service is automatically released.
}
}