Guava - EventBus example

package com.areoit.guava.eventbus;

import org.junit.Test;
import static org.junit.Assert.assertEquals;

import com.google.common.eventbus.EventBus;
import com.google.common.eventbus.Subscribe;

public class EventBusIntegerEventsTests {
 
 private static final String EVENT_BUS_ID = "numbers";

 /**
  * Case:
  *  + one listener
  *  + listener subcribe for Integer event
  *  + listener subcribe for Number event
  *  + REMEMBER: Integer IS-A Number
  */
 @Test
 public void oneIntegerEventTwoSubscribingMethod() {
 
  IntegerListener listener = new IntegerListener();
  Integer integerEvent = Integer.MAX_VALUE;
  
  EventBus eventBus = new EventBus(EVENT_BUS_ID);
  eventBus.register(listener);  
  eventBus.post(integerEvent);
  
  //check event counters
  int integerCount 
   = listener.getIntegerEventCount();
  
  int numberCount 
   = listener.getNumberEventCount();
  
  assertEquals(1, integerCount);
  assertEquals(1, numberCount);
 }
 

 class IntegerListener  {

  private int integerEventCount = 0;
  private int numberEventCount = 0;
   
  @Subscribe
  public void onIntegerEvent(Integer event) {
   ++integerEventCount;
  }
  
  @Subscribe
  public void onNumberEvent(Number event) {
   ++numberEventCount;
  }

  public int getIntegerEventCount() {
   return integerEventCount;
  }

  public int getNumberEventCount() {
   return numberEventCount;
  }
 }
 
 
}

Guava - Functions + composition

public class FunctionsTests {
 
 @Test
 public void Functions_converter_example() {
  
  Function stringToInteger = new Function() {

   @Override
   public Integer apply(String input) {
    return Integer.valueOf(input);
   }
  };
  
  Function integerToLong = new Function\() {
   @Override
   public Long apply(Integer input) {
    return Long.valueOf(input.longValue());
   }
  };
  
  Function stringToLong 
   = Functions.compose(integerToLong, stringToInteger);
  
  Long actual = stringToLong.apply("5");
  Long expected = 5L;
  
  assertEquals(expected, actual);
 }
}

Guava - Joiner

import org.junit.Test;

import com.google.common.base.Joiner;

public class Collections {

 @Test
 public void Joiner_on_list_with_one_null_value() {
  
  String actual 
   = Joiner
    .on(",")
    .skipNulls()
    .join("one",null,"two");
  
  assertEquals("one,two", actual);
 }
 
 @Test
 public void Joiner_on_map() {
  
  Map map = new HashMap();
  map.put("k1", "v1");
  map.put("k2", "v2");

  String actual 
   = Joiner
    .on(",")
    .withKeyValueSeparator(" => ")
    .join(map);
  
  assertEquals("k1 => v1,k2 => v2", actual);
 }

}