Akka/Scala example source code file (MessageJavaTest.java)

This example Akka source code file (MessageJavaTest.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

a, actor, akka, akkajunitactorsystemresource, b, c, camel, camelmessage, dispatch, hashmap, map, object, string, test, testing, testkit

The MessageJavaTest.java Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */

package akka.camel;

import akka.actor.ActorSystem;
import akka.dispatch.Mapper;
import akka.testkit.AkkaJUnitActorSystemResource;
import org.apache.camel.NoTypeConversionAvailableException;
import org.apache.camel.converter.stream.InputStreamCache;
import org.junit.ClassRule;
import org.junit.Test;

import java.io.InputStream;
import java.util.*;

import static org.junit.Assert.assertEquals;

/**
 *
 */
public class MessageJavaTest {
  private Map<String,Object> empty = new HashMap<String, Object>();

  @ClassRule
  public static AkkaJUnitActorSystemResource actorSystemResource =
    new AkkaJUnitActorSystemResource("MessageJavaTest");

  private final ActorSystem system = actorSystemResource.getSystem();
  private Camel camel = (Camel) CamelExtension.get(system);

  CamelMessage message(Object body){ return new CamelMessage(body, new HashMap<String, Object>()); }
  CamelMessage message(Object body, Map<String, Object> headers){ return new CamelMessage(body, headers); }


  @Test public void shouldConvertDoubleBodyToString() {
    assertEquals("1.4", message("1.4", empty).getBodyAs(String.class,camel.context()));
  }

  @Test(expected=NoTypeConversionAvailableException.class)
  public void shouldThrowExceptionWhenConvertingDoubleBodyToInputStream() {
    message(1.4).getBodyAs(InputStream.class,camel.context());
  }

  @Test public void shouldConvertDoubleHeaderToString() {
    CamelMessage message = message("test" , createMap("test", 1.4));
    assertEquals("1.4", message.getHeaderAs("test", String.class,camel.context()));
  }

  @Test public void shouldReturnSubsetOfHeaders() {
    CamelMessage message = message("test" , createMap("A", "1", "B", "2"));
    assertEquals(createMap("B", "2"), message.getHeaders(createSet("B")));
  }

  @Test(expected=UnsupportedOperationException.class)
  public void shouldReturnSubsetOfHeadersUnmodifiable() {
    CamelMessage message = message("test" , createMap("A", "1", "B", "2"));
    message.getHeaders(createSet("B")).put("x", "y");
  }

  @Test public void shouldReturnAllHeaders() {
    CamelMessage message = message("test" , createMap("A", "1", "B", "2"));
    assertEquals(createMap("A", "1", "B", "2"), message.getHeaders());
  }

  @Test(expected=UnsupportedOperationException.class)
  public void shouldReturnAllHeadersUnmodifiable() {
    CamelMessage message = message("test" , createMap("A", "1", "B", "2"));
    message.getHeaders().put("x", "y");
  }

  @Test public void shouldTransformBodyAndPreserveHeaders() {
    assertEquals(
      message("ab", createMap("A", "1")),
      message("a" , createMap("A", "1")).mapBody(new TestTransformer()));
  }

  @Test public void shouldConvertBodyAndPreserveHeaders() {
    assertEquals(
      message("1.4", createMap("A", "1")),
      message(1.4  , createMap("A", "1")).withBodyAs(String.class,camel.context()));
  }

  @Test public void shouldSetBodyAndPreserveHeaders() {
    assertEquals(
      message("test2" , createMap("A", "1")),
      message("test1" , createMap("A", "1")).withBody("test2"));
  }

  @Test public void shouldSetHeadersAndPreserveBody() {
    assertEquals(
      message("test1" , createMap("C", "3")),
      message("test1" , createMap("A", "1")).withHeaders(createMap("C", "3")));
  }

  @Test
  public void shouldBeAbleToReReadStreamCacheBody() throws Exception {
    CamelMessage msg = new CamelMessage(new InputStreamCache("test1".getBytes("utf-8")), empty);
    assertEquals("test1", msg.getBodyAs(String.class, camel.context()));
    // re-read
    assertEquals("test1", msg.getBodyAs(String.class, camel.context()));
  }

  private static Set<String> createSet(String... entries) {
    HashSet<String> set = new HashSet<String>();
    set.addAll(Arrays.asList(entries));
    return set;
  }

  private static Map<String, Object> createMap(Object... pairs) {
    HashMap<String, Object> map = new HashMap<String, Object>();
    for (int i = 0; i < pairs.length; i += 2) {
      map.put((String)pairs[i], pairs[i+1]);
    }
    return map;
  }

  private static class TestTransformer extends Mapper<String, String> {
    @Override
    public String apply(String param) {
      return param + "b";
    }
  }

}