Adding swagger to your DropWizard application

Adding swagger to your dropwizard application is very easy.  I followed the tutorial for information on how to do so, and here were the actual changes I made.

Step 1: Update your pom.xml file

<!-- Swagger UI -->
        <dependency>
            <groupId>com.wordnik</groupId>
            <artifactId>swagger-jaxrs_2.10</artifactId>
            <version>1.3.12</version>
        </dependency>

        <!-- CORS support for Swagger-->
        <dependency>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-servlets</artifactId>
            <version>9.2.9.v20150224</version>
        </dependency>

Step 2: Update your DW application configuration

To make the configuration portable across environments, you can add the base path to your configuration file.

@Valid
@NotNull
@JsonProperty
private String swaggerBasePath;
public String getSwaggerBasePath(){ return swaggerBasePath; }</pre>

Step 3: Update the Application class

Add the swagger init to the run method of the Application Class.

// init Swagger resources
initSwagger(configuration, environment);

And add the definition of that method to the same class.

private void initSwagger(ExampleServiceConfiguration configuration, Environment environment) {
    // Swagger Resource
    environment.jersey().register(new ApiListingResourceJSON());

    // Swagger providers
    environment.jersey().register(new ApiDeclarationProvider());
    environment.jersey().register(new ResourceListingProvider());

    // Swagger Scanner, which finds all the resources for @Api Annotations
    ScannerFactory.setScanner(new DefaultJaxrsScanner());

    // Add the reader, which scans the resources and extracts the resource information
    ClassReaders.setReader(new DefaultJaxrsApiReader());

    // required CORS support
    FilterRegistration.Dynamic filter = environment.servlets().addFilter("CORS", CrossOriginFilter.class);
    filter.addMappingForUrlPatterns(EnumSet.allOf(DispatcherType.class), true, "/*");
    filter.setInitParameter("allowedOrigins", "*"); // allowed origins comma separated
    filter.setInitParameter("allowedHeaders", "Content-Type,Authorization,X-Requested-With,Content-Length,Accept,Origin");
    filter.setInitParameter("allowedMethods", "GET,PUT,POST,DELETE,OPTIONS,HEAD");
    filter.setInitParameter("preflightMaxAge", "5184000"); // 2 months
    filter.setInitParameter("allowCredentials", "true");

    // Set the swagger config options
    SwaggerConfig config = ConfigFactory.config();
    config.setApiVersion("1.0.1");
    config.setBasePath(configuration.getSwaggerBasePath());
}

Step 4: Update application yml file

swaggerBasePath: http://localhost:9080

Step 5: Annotate your classes

import com.codahale.metrics.annotation.Timed;
import com.wordnik.swagger.annotations.Api;
import com.wordnik.swagger.annotations.ApiOperation;
import com.wordnik.swagger.annotations.ApiResponse;
import com.wordnik.swagger.annotations.ApiResponses;
import javax.ws.rs.GET;
import javax.ws.rs.Path;

/**
 * Created by mlynch 
 */
@Path("/hello")
@Api(value="/hello", description="Operations on the hello object")
public class HelloResource {

    private final MessagesConfiguration conf;

    public HelloResource(MessagesConfiguration conf) {
        this.conf = conf;
    }

    @GET
    @Timed
    @ApiOperation(value="Return a simple greeting", notes="some day this will do more, it believes in a growth mentality.")
    @ApiResponses(value={
            @ApiResponse(code=400, message="Invalid ID"),
    })
    public String sayHello() {
        return conf.getHello();
    }

}

Full tutorial link here: https://github.com/swagger-api/swagger-core/wiki/Swagger-Core-JAX-RS-Project-Setup-1.5.X