How to integrate Swagger no config setup with Jers

Question

I'm trying to do a barebones Swagger setup with a Jersey 2 project hosted on Tomcat 8.5. I first generated the jersey project with the following snippet from the Jersey getting started guide (https://jersey.github.io/documentation/latest/getting-started.html):

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=2.27

Then I added the Swagger dependencies from the swagger getting started guide (https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X---Getting-started):

<dependency>
  <groupId>io.swagger.core.v3</groupId>
  <artifactId>swagger-jaxrs2</artifactId>
  <version>2.0.0</version>
</dependency>
<dependency>
  <groupId>io.swagger.core.v3</groupId>
  <artifactId>swagger-jaxrs2-servlet-initializer</artifactId>
  <version>2.0.0</version>
</dependency>

When hit the api at http://localhost:8080/simple-service-webapp/webapi/myresource I get the correct response. When I hit http://localhost:8080/simple-service-webapp/webapi/openapi.json I get a 404 Not Found.

Any ideas?

Here's what my pom looks like:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

<modelVersion>4.0.0</modelVersion>

<groupId>com.example</groupId>
<artifactId>simple-service-webapp</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>simple-service-webapp</name>

<build>
    <finalName>simple-service-webapp</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.5.1</version>
            <inherited>true</inherited>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
            </configuration>
        </plugin>
    </plugins>
</build>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey</groupId>
            <artifactId>jersey-bom</artifactId>
            <version>${jersey.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet-core</artifactId>
        <!-- use the following artifactId if you don't need servlet 2.x compatibility -->
        <!-- artifactId>jersey-container-servlet</artifactId -->
    </dependency>
    <dependency>
        <groupId>org.glassfish.jersey.inject</groupId>
        <artifactId>jersey-hk2</artifactId>
    </dependency>
    <!-- uncomment this to get JSON support
    <dependency>
        <groupId>org.glassfish.jersey.media</groupId>
        <artifactId>jersey-media-json-binding</artifactId>
    </dependency>
    -->
    <dependency>
      <groupId>io.swagger.core.v3</groupId>
      <artifactId>swagger-jaxrs2</artifactId>
      <version>2.0.0</version>
    </dependency>
    <dependency>
      <groupId>io.swagger.core.v3</groupId>
      <artifactId>swagger-jaxrs2-servlet-initializer</artifactId>
      <version>2.0.0</version>
    </dependency>
</dependencies>
<properties>
    <jersey.version>2.27</jersey.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

Answer 1

You still need to register the OpenApi resources. These are the JAX-RS resource classes that serve up the JSON. Since you are using web.xml for your configuration, you can simply add the swagger package to the list of packages to scan.

<servlet>
    <servlet-name>Jersey Web Application</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>
            com.example,
            io.swagger.v3.jaxrs2.integration.resources
        </param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

Notice I added the io.swagger.v3.jaxrs2.integration.resources package to the list, delimited by comma. This will tell Jersey to scan that package, and it will discover and register both the AcceptHeaderOpenApiResource and the OpenApiResource. The difference between the two is that the former serves up the path /openapi and the data format is determined by the Accept header in the request, and the latter serves up the path /openapi.{type:json|yaml}, where the data format is determined by the extension (.json or .yaml) in the path.