Chapter 1. Getting Started

Jersey project is built using Apache Maven software project build and management tool. All modules produced as part of Jersey project build are pushed to the Central Maven Repository. Therefore it is very convenient to work with Jersey for any Maven-based project as all the released (non-SNAPSHOT) Jersey dependencies are readily available without a need to configure a special maven repository to consume the Jersey modules.

<snapshotRepository>
    <id>ossrh</id>
    <name>Sonatype Nexus Snapshots</name>
    <url>https://jakarta.oss.sonatype.org/content/repositories/snapshots/</url>
</snapshotRepository>

Since starting from a Maven project is the most convenient way for working with Jersey, let's now have a look at this approach. We will now create a new Jersey project that runs on top of a Grizzly container. We will use a Jersey-provided maven archetype. To create the project, execute the following Maven command in the directory where the new project should reside:

mvn archetype:generate -DarchetypeArtifactId=jersey-quickstart-grizzly2 \
-DarchetypeGroupId=org.glassfish.jersey.archetypes -DinteractiveMode=false \
-DgroupId=com.example -DartifactId=simple-service -Dpackage=com.example \
-DarchetypeVersion=2.46

Feel free to adjust the groupId, package and/or artifactId of your new project. Alternatively, you can change it by updating the new project pom.xml once it gets generated.

Once the project generation from a Jersey maven archetype is successfully finished, you should see the new simple-service project directory created in your current location. The directory contains a standard Maven project structure:

There are 2 classes in the project source directory in the com.example package. The Main class is responsible for bootstrapping the Grizzly container as well as configuring and deploying the project's JAX-RS application to the container. Another class in the same package is MyResource class, that contains implementation of a simple JAX-RS resource. It looks like this:

package com.example;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

/**
 * Root resource (exposed at "myresource" path)
 */
@Path("myresource")
public class MyResource {

    /**
     * Method handling HTTP GET requests. The returned object will be sent
     * to the client as "text/plain" media type.
     *
     * @return String that will be returned as a text/plain response.
     */
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String getIt() {
        return "Got it!";
    }
}

A JAX-RS resource is an annotated POJO that provides so-called resource methods that are able to handle HTTP requests for URI paths that the resource is bound to. See Chapter 3, JAX-RS Application, Resources and Sub-Resources for a complete guide to JAX-RS resources. In our case, the resource exposes a single resource method that is able to handle HTTP GET requests, is bound to /myresource URI path and can produce responses with response message content represented in "text/plain" media type. In this version, the resource returns the same "Got it!" response to all client requests.

The last piece of code that has been generated in this skeleton project is a MyResourceTest unit test class that is located in the same com.example package as the MyResource class, however, this unit test class is placed into the maven project test source directory src/test/java (certain code comments and JUnit imports have been excluded for brevity):

package com.example;

import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.WebTarget;

import org.glassfish.grizzly.http.server.HttpServer;

...

public class MyResourceTest {

    private HttpServer server;
    private WebTarget target;

    @BeforeEach
    public void setUp() throws Exception {
        server = Main.startServer();

        Client c = ClientBuilder.newClient();
        target = c.target(Main.BASE_URI);
    }

    @AfterEach
    public void tearDown() throws Exception {
        server.stop();
    }

    /**
     * Test to see that the message "Got it!" is sent in the response.
     */
    @Test
    public void testGetIt() {
        String responseMsg = target.path("myresource").request().get(String.class);
        assertEquals("Got it!", responseMsg);
    }
}

In this unit test, a Grizzly container is first started and server application is deployed in the test setUp() method by a static call to Main.startServer(). Next, JAX-RS client components are created in the same test set-up method. First a new JAX-RS client instance c is built and then a JAX-RS web target component pointing to the context root of our application deployed at http://localhost:8080/myapp/ (a value of Main.BASE_URI constant) is stored into a target field of the unit test class. This field is then used in the actual unit test method (testGetIt()).

In the testGetIt() method a fluent JAX-RS Client API is used to connect to and send a HTTP GET request to the MyResource JAX-RS resource class listening on /myresource URI. As part of the same fluent JAX-RS API method invocation chain, a response is read as a Java String type. On the second line in the test method, the response content string returned from the server is compared with the expected phrase in the test assertion. To learn more about using JAX-RS Client API, please see the Chapter 5, Client API chapter.

Now that we have seen the content of the project, let's try to test-run it. To do this, we need to invoke following command on the command line:

mvn clean test

This will compile the project and run the project unit tests. We should see a similar output that informs about a successful build once the build is finished:

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  7.519 s
[INFO] Finished at: 2021-01-29T08:16:04+01:00
[INFO] ------------------------------------------------------------------------

Now that we have verified that the project compiles and that the unit test passes, we can execute the application in a standalone mode. To do this, run the following maven command:

mvn exec:java

The application starts and you should soon see the following notification in your console:

May 26, 2013 8:08:45 PM org.glassfish.grizzly.http.server.NetworkListener start
INFO: Started listener bound to [localhost:8080]
Jan 29, 2021 8:33:02 AM org.glassfish.grizzly.http.server.HttpServer start
INFO: [HttpServer] Started.
Jersey app started with WADL available at http://localhost:8080/myapp/application.wadl
Hit enter to stop it...

This informs you that the application has been started and it's WADL descriptor is available at http://localhost:8080/myapp/application.wadl URL. You can retrieve the WADL content by executing a curl http://localhost:8080/myapp/application.wadl command in your console or by typing the WADL URL into your favorite browser. You should get back an XML document in describing your deployed RESTful application in a WADL format. To learn more about working with WADL, check the Chapter 19, WADL Support chapter.

The last thing we should try before concluding this section is to see if we can communicate with our resource deployed at /myresource path. We can again either type the resource URL in the browser or we can use curl:

$ curl http://localhost:8080/myapp/myresource
Got it!

As we can see, the curl command returned with the Got it! message that was sent by our resource. We can also ask curl to provide more information about the response, for example we can let it display all response headers by using the -i switch:

curl -i http://localhost:8080/myapp/myresource
HTTP/1.1 200 OK
Content-Type: text/plain
Content-Length: 7

Got it!

Here we see the whole content of the response message that our Jersey/JAX-RS application returned, including all the HTTP headers. Notice the Content-Type: text/plain header that was derived from the value of @Produces annotation attached to the MyResource class.

In case you want to see even more details about the communication between our curl client and our resource running on Jersey in a Grizzly I/O container, feel free to try other various options and switches that curl provides. For example, this last command will make curl output a lot of additional information about the whole communication:

$ curl -v http://localhost:8080/myapp/myresource
*   Trying 127.0.0.1:8080...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 8080 (#0)
> GET /myapp/myresource HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.68.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Content-Type: text/plain
< Content-Length: 7
<
* Connection #0 to host localhost left intact
Got it!

To create a Web Application that can be packaged as WAR and deployed in a Servlet container follow a similar process to the one described in Section 1.1, “Creating a New Project from Maven Archetype”. In addition to the Grizzly-based archetype, Jersey provides also a Maven archetype for creating web application skeletons. To create the new web application skeleton project, execute the following Maven command in the directory where the new project should reside:

mvn archetype:generate -DarchetypeArtifactId=jersey-quickstart-webapp \
                -DarchetypeGroupId=org.glassfish.jersey.archetypes -DinteractiveMode=false \
                -DgroupId=com.example -DartifactId=simple-service-webapp -Dpackage=com.example \
                -DarchetypeVersion=2.46

As with the Grizzly based project, feel free to adjust the groupId, package and/or artifactId of your new web application project. Alternatively, you can change it by updating the new project pom.xml once it gets generated.

Once the project generation from a Jersey maven archetype is successfully finished, you should see the new simple-service-webapp project directory created in your current location. The directory contains a standard Maven project structure, similar to the simple-service project content we have seen earlier, except it is extended with an additional web application specific content:

The project contains the same MyResouce JAX-RS resource class. It does not contain any unit tests as well as it does not contain a Main class that was used to setup Grizzly container in the previous project. Instead, it contains the standard Java EE web application web.xml deployment descriptor under src/main/webapp/WEB-INF. The last component in the project is an index.jsp page that serves as a client for the MyResource resource class that is packaged and deployed with the application.

To compile and package the application into a WAR, invoke the following maven command in your console:

mvn clean package

A successful build output will produce an output similar to the one below:

Results :

Tests run: 0, Failures: 0, Errors: 0, Skipped: 0

[INFO]
[INFO] --- maven-war-plugin:2.2:war (default-war) @ simple-service-webapp ---
[INFO] Packaging webapp
[INFO] Assembling webapp [simple-service-webapp] in [.../simple-service-webapp/target/simple-service-webapp]
[INFO] Processing war project
[INFO] Copying webapp resources [.../simple-service-webapp/src/main/webapp]
[INFO] Webapp assembled in [110 msecs]
[INFO] Building war: .../simple-service-webapp/target/simple-service-webapp.war
[INFO] WEB-INF/web.xml already added, skipping
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  4.520 s
[INFO] Finished at: 2021-01-29T08:42:11+01:00
[INFO] ------------------------------------------------------------------------

Now you are ready to take the packaged WAR (located under ./target/simple-service-webapp.war) and deploy it to a Servlet container of your choice.

To create a Web Application that can be either packaged as WAR and deployed in a Servlet container or that can be pushed and deployed on Heroku the process is very similar to the one described in Section 1.4, “Creating a JavaEE Web Application”. To create the new web application skeleton project, execute the following Maven command in the directory where the new project should reside:

mvn archetype:generate -DarchetypeArtifactId=jersey-heroku-webapp \
                -DarchetypeGroupId=org.glassfish.jersey.archetypes -DinteractiveMode=false \
                -DgroupId=com.example -DartifactId=simple-heroku-webapp -Dpackage=com.example \
                -DarchetypeVersion=2.46

Adjust the groupId, package and/or artifactId of your new web application project to your needs or, alternatively, you can change it by updating the new project pom.xml once it gets generated.

Once the project generation from a Jersey maven archetype is successfully finished, you should see the new simple-heroku-webapp project directory created in your current location. The directory contains a standard Maven project structure:

The project contains one JAX-RS resource class, MyResouce, and one resource method which returns simple text message. To make sure the resource is properly tested there is also a end-to-end test-case in MyResourceTest (the test is based on JerseyTest from our Chapter 29, Jersey Test Framework). Similarly to simple-service-webapp, the project contains the standard Java EE web application web.xml deployment descriptor under src/main/webapp/WEB-INF since the goal is to deploy the application in a Servlet container (the application will run in Jetty on Heroku).

To compile and package the application into a WAR, invoke the following maven command in your console:

mvn clean package

A successful build output will produce an output similar to the one below:

    Results :

    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

    [INFO]
    [INFO] --- maven-war-plugin:2.2:war (default-war) @ simple-heroku-webapp ---
    [INFO] Packaging webapp
    [INFO] Assembling webapp [simple-heroku-webapp] in [.../simple-heroku-webapp/target/simple-heroku-webapp]
    [INFO] Processing war project
    [INFO] Copying webapp resources [.../simple-heroku-webapp/src/main/webapp]
    [INFO] Webapp assembled in [122 msecs]
    [INFO] Building war: .../simple-heroku-webapp/target/simple-heroku-webapp.war
    [INFO] WEB-INF/web.xml already added, skipping
    [INFO]
    [INFO] --- maven-dependency-plugin:2.8:copy-dependencies (copy-dependencies) @ simple-heroku-webapp ---
    [INFO] Copying jetty-util-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-util-9.4.28.v20200408.jar
    [INFO] Copying jersey-hk2-2.33.jar to .../simple-heroku-webapp/target/dependency/jersey-hk2-2.33.jar
    [INFO] Copying javassist-3.25.0-GA.jar to .../simple-heroku-webapp/target/dependency/javassist-3.25.0-GA.jar
    [INFO] Copying jakarta.inject-2.6.1.jar to .../simple-heroku-webapp/target/dependency/jakarta.inject-2.6.1.jar
    [INFO] Copying hk2-locator-2.6.1.jar to .../simple-heroku-webapp/target/dependency/hk2-locator-2.6.1.jar
    [INFO] Copying hk2-utils-2.6.1.jar to .../simple-heroku-webapp/target/dependency/hk2-utils-2.6.1.jar
    [INFO] Copying hk2-api-2.6.1.jar to .../simple-heroku-webapp/target/dependency/hk2-api-2.6.1.jar
    [INFO] Copying jetty-webapp-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-webapp-9.4.28.v20200408.jar
    [INFO] Copying jakarta.annotation-api-1.3.5.jar to .../simple-heroku-webapp/target/dependency/jakarta.annotation-api-1.3.5.jar
    [INFO] Copying jersey-server-2.33.jar to .../simple-heroku-webapp/target/dependency/jersey-server-2.33.jar
    [INFO] Copying jakarta.ws.rs-api-2.1.6.jar to .../simple-heroku-webapp/target/dependency/jakarta.ws.rs-api-2.1.6.jar
    [INFO] Copying osgi-resource-locator-1.0.3.jar to .../simple-heroku-webapp/target/dependency/osgi-resource-locator-1.0.3.jar
    [INFO] Copying aopalliance-repackaged-2.6.1.jar to .../simple-heroku-webapp/target/dependency/aopalliance-repackaged-2.6.1.jar
    [INFO] Copying jetty-servlet-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-servlet-9.4.28.v20200408.jar
    [INFO] Copying jetty-xml-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-xml-9.4.28.v20200408.jar
    [INFO] Copying jersey-container-servlet-2.33.jar to .../simple-heroku-webapp/target/dependency/jersey-container-servlet-2.33.jar
    [INFO] Copying jetty-io-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-io-9.4.28.v20200408.jar
    [INFO] Copying jetty-security-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-security-9.4.28.v20200408.jar
    [INFO] Copying jetty-server-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-server-9.4.28.v20200408.jar
    [INFO] Copying javax.servlet-3.0.0.v201112011016.jar to .../simple-heroku-webapp/target/dependency/javax.servlet-3.0.0.v201112011016.jar
    [INFO] Copying jersey-common-2.33.jar to .../simple-heroku-webapp/target/dependency/jersey-common-2.33.jar
    [INFO] Copying jakarta.validation-api-2.0.2.jar to .../simple-heroku-webapp/target/dependency/jakarta.validation-api-2.0.2.jar
    [INFO] Copying jersey-container-servlet-core-2.33.jar to .../simple-heroku-webapp/target/dependency/jersey-container-servlet-core-2.33.jar
    [INFO] Copying jersey-client-2.33.jar to .../simple-heroku-webapp/target/dependency/jersey-client-2.33.jar
    [INFO] Copying jetty-http-9.4.28.v20200408.jar to .../simple-heroku-webapp/target/dependency/jetty-http-9.4.28.v20200408.jar
    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESS
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time:  12.009 s
    [INFO] Finished at: 2021-01-29T08:48:04+01:00
    [INFO] ------------------------------------------------------------------------

Now that you know everything went as expected you are ready to:

    $ git init
    Initialized empty Git repository in /.../simple-heroku-webapp/.git/

    $ heroku create
    Creating simple-heroku-webapp... done, stack is cedar
    http://simple-heroku-webapp.herokuapp.com/ | git@heroku.com:simple-heroku-webapp.git
    Git remote heroku added

    $ git add src/ pom.xml Procfile system.properties

    $ git commit -a -m "initial commit"
    [master (root-commit) e2b58e3] initial commit
     7 files changed, 221 insertions(+)
     create mode 100644 Procfile
     create mode 100644 pom.xml
     create mode 100644 src/main/java/com/example/MyResource.java
     create mode 100644 src/main/java/com/example/heroku/Main.java
     create mode 100644 src/main/webapp/WEB-INF/web.xml
     create mode 100644 src/test/java/com/example/MyResourceTest.java
     create mode 100644 system.properties

    $ git push heroku master
    Counting objects: 21, done.
    Delta compression using up to 8 threads.
    Compressing objects: 100% (11/11), done.
    Writing objects: 100% (21/21), 3.73 KiB | 0 bytes/s, done.
    Total 21 (delta 0), reused 0 (delta 0)

    -----> Java app detected
    -----> Installing OpenJDK 1.8... done
    -----> Installing Maven 3.6.3... done
    -----> Installing settings.xml... done
    -----> executing /app/tmp/cache/.maven/bin/mvn -B -Duser.home=/tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd -Dmaven.repo.local=/app/tmp/cache/.m2/repository -s /app/tmp/cache/.m2/settings.xml -DskipTests=true clean install
    [INFO] Scanning for projects...
    [INFO]
    [INFO] ------------------ com.example:simple-heroku-webapp ------------------
    [INFO] Building simple-heroku-webapp 1.0-SNAPSHOT
    [INFO] --------------------------------[ war ]---------------------------------
    [INFO]
    [INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ simple-heroku-webapp ---
    [INFO] Deleting /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target
    [INFO]
    [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ simple-heroku-webapp ---
    [INFO] Using 'UTF-8' encoding to copy filtered resources.
    [INFO] skip non existing resourceDirectory /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/src/main/resources
    [INFO]
    [INFO] --- maven-compiler-plugin:2.5.1:compile (default-compile) @ simple-heroku-webapp ---
    [INFO] Compiling 2 source files to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/classes
    [INFO]
    [INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ simple-heroku-webapp ---
    [INFO] Using 'UTF-8' encoding to copy filtered resources.
    [INFO] skip non existing resourceDirectory /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/src/test/resources
    [INFO]
    [INFO] --- maven-compiler-plugin:2.5.1:testCompile (default-testCompile) @ simple-heroku-webapp ---
    [INFO] Compiling 1 source file to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/test-classes
    [INFO]
    [INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ simple-heroku-webapp ---
    [INFO] Surefire report directory: /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/surefire-reports

    -------------------------------------------------------
    T E S T S
    -------------------------------------------------------
    Running com.example.MyResourceTest
    Jan 29, 2021 9:13:20 AM org.glassfish.jersey.test.grizzly.GrizzlyTestContainerFactory$GrizzlyTestContainer
    INFO: Creating GrizzlyTestContainer configured at the base URI http://localhost:9998/
    Jan 29, 2021 9:13:20 AM org.glassfish.jersey.server.wadl.WadlFeature configure
    WARNING: JAXBContext implementation could not be found. WADL feature is disabled.
    Jan 29, 2021 9:13:21 AM org.glassfish.grizzly.http.server.NetworkListener start
    INFO: Started listener bound to [localhost:9998]
    Jan 29, 2021 9:13:21 AM org.glassfish.grizzly.http.server.HttpServer start
    INFO: [HttpServer] Started.
    Jan 29, 2021 9:13:21 AM org.glassfish.grizzly.http.server.NetworkListener shutdownNow
    INFO: Stopped listener bound to [localhost:9998]
    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.476 sec

    Results :

    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

    [INFO]
    [INFO] --- maven-war-plugin:2.2:war (default-war) @ simple-heroku-webapp ---
    [INFO] Packaging webapp
    [INFO] Assembling webapp [simple-heroku-webapp] in [/tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/simple-heroku-webapp]
    [INFO] Processing war project
    [INFO] Copying webapp resources [/tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/src/main/webapp]
    [INFO] Webapp assembled in [115 msecs]
    [INFO] Building war: /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/simple-heroku-webapp.war
    [INFO] WEB-INF/web.xml already added, skipping
    [INFO]
    [INFO] --- maven-dependency-plugin:2.8:copy-dependencies (copy-dependencies) @ simple-heroku-webapp ---
    [INFO] Copying jetty-util-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-util-9.4.28.v20200408.jar
    [INFO] Copying jersey-hk2-2.33.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jersey-hk2-2.33.jar
    [INFO] Copying javassist-3.25.0-GA.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/javassist-3.25.0-GA.jar
    [INFO] Copying jakarta.inject-2.6.1.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jakarta.inject-2.6.1.jar
    [INFO] Copying hk2-locator-2.6.1.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/hk2-locator-2.6.1.jar
    [INFO] Copying hk2-utils-2.6.1.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/hk2-utils-2.6.1.jar
    [INFO] Copying hk2-api-2.6.1.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/hk2-api-2.6.1.jar
    [INFO] Copying jetty-webapp-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-webapp-9.4.28.v20200408.jar
    [INFO] Copying jakarta.annotation-api-1.3.5.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jakarta.annotation-api-1.3.5.jar
    [INFO] Copying jersey-server-2.33.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jersey-server-2.33.jar
    [INFO] Copying jakarta.ws.rs-api-2.1.6.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jakarta.ws.rs-api-2.1.6.jar
    [INFO] Copying osgi-resource-locator-1.0.3.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/osgi-resource-locator-1.0.3.jar
    [INFO] Copying aopalliance-repackaged-2.6.1.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/aopalliance-repackaged-2.6.1.jar
    [INFO] Copying jetty-servlet-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-servlet-9.4.28.v20200408.jar
    [INFO] Copying jetty-xml-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-xml-9.4.28.v20200408.jar
    [INFO] Copying jersey-container-servlet-2.33.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jersey-container-servlet-2.33.jar
    [INFO] Copying jetty-io-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-io-9.4.28.v20200408.jar
    [INFO] Copying jetty-security-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-security-9.4.28.v20200408.jar
    [INFO] Copying jetty-server-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-server-9.4.28.v20200408.jar
    [INFO] Copying javax.servlet-3.0.0.v201112011016.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/javax.servlet-3.0.0.v201112011016.jar
    [INFO] Copying jersey-common-2.33.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jersey-common-2.33.jar
    [INFO] Copying jakarta.validation-api-2.0.2.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jakarta.validation-api-2.0.2.jar
    [INFO] Copying jersey-container-servlet-core-2.33.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jersey-container-servlet-core-2.33.jar
    [INFO] Copying jersey-client-2.33.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jersey-client-2.33.jar
    [INFO] Copying jetty-http-9.4.28.v20200408.jar to /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/dependency/jetty-http-9.4.28.v20200408.jar
    [INFO]
    [INFO] --- maven-install-plugin:2.4:install (default-install) @ simple-heroku-webapp ---
    [INFO] Installing /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/target/simple-heroku-webapp.war to /app/tmp/cache/.m2/repository/com/example/simple-heroku-webapp/1.0-SNAPSHOT/simple-heroku-webapp-1.0-SNAPSHOT.war
    [INFO] Installing /tmp/build_992cc747-26d6-4800-bdb1-add47b9583cd/pom.xml to /app/tmp/cache/.m2/repository/com/example/simple-heroku-webapp/1.0-SNAPSHOT/simple-heroku-webapp-1.0-SNAPSHOT.pom
    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESS
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time:  5.857 s
    [INFO] Finished at: 2021-01-29T09:13:23+01:00
    [INFO] ------------------------------------------------------------------------
    -----> Discovering process types
           Procfile declares types -> web

    -----> Compiled slug size: 75.9MB
    -----> Launching... done, v6
           http://simple-heroku-webapp.herokuapp.com deployed to Heroku

    To git@heroku.com:simple-heroku-webapp.git
     * [new branch]      master -> master

In the sections above, we have covered an approach how to get dirty with Jersey quickly. Please consult the other sections of the Jersey User Guide to learn more about Jersey and JAX-RS. Even though we try our best to cover as much as possible in the User Guide, there is always a chance that you would not be able to get a full answer to the problem you are solving. In that case, consider diving in our examples that provide additional tips and hints to the features you may want to use in your projects.

Jersey codebase contains a number of useful examples on how to use various JAX-RS and Jersey features. Feel free to browse through the code of individual Jersey Examples in the Jersey source repository. For off-line browsing, you can also download a bundle with all the examples from here.