DefaultExceptionHandlerTest.java

/*******************************************************************************
 * Mission Control Technologies, Copyright (c) 2009-2012, United States Government
 * as represented by the Administrator of the National Aeronautics and Space 
 * Administration. All rights reserved.
 *
 * The MCT platform is 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.
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 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 
 * License for the specific language governing permissions and limitations under 
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package gov.nasa.arc.mct.exception;

import static org.testng.Assert.assertEquals;

import java.lang.Thread.UncaughtExceptionHandler;
import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;
import org.apache.log4j.spi.LoggingEvent;
import org.apache.log4j.varia.NullAppender;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class DefaultExceptionHandlerTest {

    protected static class MyAppender extends NullAppender {
        
        List<LoggingEvent> events = new ArrayList<LoggingEvent>();

        @Override
        protected void append(LoggingEvent event) {
            events.add(event);
        }

        @Override
        public void doAppend(LoggingEvent event) {
            append(event);
        }

        public void clearEvents() {
            events.clear();
        }

        public List<LoggingEvent> getEvents() {
            return events;
        }

    }
    // Then, configure the underlying logger the way we want.
    Logger logger = Logger.getLogger(DefaultExceptionHandler.class);
    MyAppender appender = new MyAppender();

    @BeforeClass
    public void initLogging() {
        logger.addAppender(appender);
    }
    
    @BeforeMethod
    public void initTest() {
        appender.clearEvents();
    }
    
    @AfterMethod
    public void cleanTest() {
        appender.clearEvents();
    }
    
    
    @Test 
    public void testInstantiation() throws Exception {
        DefaultExceptionHandler handler = new DefaultExceptionHandler(false);
        assertEquals(appender.getEvents().size(), 1);
    }
    
    @Test
    public void testExceptionHandler() throws Exception {
        UncaughtExceptionHandler handler = Thread.getDefaultUncaughtExceptionHandler();
        Thread.setDefaultUncaughtExceptionHandler(new DefaultExceptionHandler(false));
        
        Thread t = new Thread() {
            public void run() {
                throw new RuntimeException("Should be uncaught");
            }
        };
        t.start();
        t.join();
        
        Thread.setDefaultUncaughtExceptionHandler(handler);
        assertEquals(appender.getEvents().size(), 2);
    }
    
}