Welcome to the Project Java MicroService

A base implementation for a microservice.

The Core Service will listen on IP 0.0.0.0 The base configuration will start Servlets at port 7080 and REST-Endpoints at 7081.

SNAPSHOTS

If you are using maven you could add the following to your settings.xml to get the snapshots.

   <profile>
      <id>allow-snapshots</id>
      <activation>
        <activeByDefault>true</activeByDefault>
      </activation>
      <repositories>
        <repository>
          <id>snapshots-repo</id>
          <url>https://oss.sonatype.org/content/repositories/snapshots</url>
          <releases>
            <enabled>false</enabled>
          </releases>
          <snapshots>
            <enabled>true</enabled>
            <updatePolicy>always</updatePolicy>
          </snapshots>
        </repository>
      </repositories>
    </profile>

Getting started

The use of the MicroService is fairly simple. Just call Main.deploy(). This will start the MicroService with all servlets and REST endpoints it can find.

REST example

Let's create a simple service that will multiply two parameters. The service will listen on the path /multiply and returns an Integer. Here is the code:

@Path("/multiply")
public class Service {

  @GET()
  @Produces("text/plain")
  public int get(@QueryParam("x") int x, @QueryParam("y") int y) {
    return Math.multiplyExact(x, y);
  }
}

And the corresponding JUnit Test:

public class RestTest {

  @Test
  public void testRestPath() throws Exception {
    Main.deploy();
    
    Client client = ClientBuilder.newClient();

    final String generateURL = TestPortProvider.generateURL("/rest" + "/multiply");
    System.out.println("generateURL = " + generateURL);
    int val = client
        .target(generateURL)
        .queryParam("x", 2)
        .queryParam("y", 21)
        .request()
        .get(Integer.class);
    Assert.assertEquals(42, val); // the only truth
    
    client.close();
    Main.stop();
  }

}

Servlet example

Here is a simple WebServlet, that will be deployed by the MicroService as soon as Main.deploy() is called:

@WebServlet(urlPatterns = "/hello")
public class HelloServlet extends HttpServlet {

  @Override
  protected void doGet(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
    PrintWriter writer = resp.getWriter();
    writer.write("hello " + req.getParameter("name"));
    writer.close();
  }

  @Override
  protected void doPost(final HttpServletRequest req, final HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
  }
}

And the corresponding JUnit Test:

public class ServletTest extends BaseTest{
  private static String url;

  @Before
  public void setUp() throws Exception {
    Main.deploy();
    url = "http://127.0.0.1:" + System.getProperty(MainUndertow.SERVLET_PORT_PROPERTY)
        + MainUndertow.MYAPP
        + HelloServlet.class.getAnnotation(WebServlet.class).urlPatterns()[0];
    System.out.println("generateURL = " + url);
  }
  
  @After
  public void tearDown() throws Exception {
    Main.stop();
  }

  @Test
  public void testServletGetRequest() throws Exception {
    Client client = ClientBuilder.newClient();

    Response response = client
        .target(url)
        .queryParam("name", "marvin")
        .request()
        .get();
    Assert.assertEquals("hello marvin", response.readEntity(String.class));
    response.close();
    client.close();
  }
}

Examples

See rapidpm-microservice-examples for more demos