ServletContext null - Jersey + Grizzly2 Standalone - 1.5.x

[BGaunitz]

When using Grizzly2 in standalone mode, ServletContext is not available.

NPE at

• com.wordnik.swagger.jaxrs.listing.ApiListingResource.scan(ApiListingResource.java:47)
• com.wordnik.swagger.jaxrs.listing.ApiListingResource.getListingJson(ApiListingResource.java:68)

https://jersey.java.net/documentation/latest/jaxrs-resources.html#d0e2742 [3.6]

[Plonk42]

Same for me, using:

        <dependency>
            <groupId>org.glassfish.grizzly</groupId>
            <artifactId>grizzly-http-servlet-server</artifactId>
            <version>2.3.21</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-grizzly2-http</artifactId>
            <version>2.18</version>
        </dependency>
        <dependency>
            <groupId>io.swagger</groupId>
            <artifactId>swagger-jersey2-jaxrs</artifactId>
            <version>1.5.0</version>
        </dependency>

java.lang.NullPointerException
    at io.swagger.jaxrs.listing.ApiListingResource.getListingJson(ApiListingResource.java:90)

Line 90 being:

        Swagger swagger = (Swagger) context.getAttribute("swagger");

Maybe related to: http://stackoverflow.com/questions/29974887/jersey-containerrequestfilter-does-not-get-context-servletrequest

[webron]

Yeah, it's related to Grizzly not using a servlet container. We need to find a work around for it.

[BGaunitz]

Hi, I fixed it quick and dirty which is sufficient for me. May be it can be used for a solid solution.

Best regards,
Benjamin

package com.wordnik.swagger.jaxrs.listing;

import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Application;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Cookie;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.wordnik.swagger.annotations.ApiOperation;
import com.wordnik.swagger.config.FilterFactory;
import com.wordnik.swagger.config.Scanner;
import com.wordnik.swagger.config.ScannerFactory;
import com.wordnik.swagger.config.SwaggerConfig;
import com.wordnik.swagger.core.filter.SpecFilter;
import com.wordnik.swagger.core.filter.SwaggerSpecFilter;
import com.wordnik.swagger.jaxrs.Reader;
import com.wordnik.swagger.jaxrs.config.JaxrsScanner;
import com.wordnik.swagger.models.Swagger;
import com.wordnik.swagger.util.Yaml;

@Path("/")
public class ApiListingResource {
    Logger LOGGER = LoggerFactory.getLogger(ApiListingResource.class);

    static boolean initialized = false;
    static Swagger swagger = null;

    @Context
    ServletContext context;

    protected synchronized Swagger scan(Application app, ServletConfig sc) {
        Scanner scanner = ScannerFactory.getScanner();
        LOGGER.debug("using scanner " + scanner);

        if (scanner != null) {
            SwaggerSerializers.setPrettyPrint(scanner.getPrettyPrint());
            if (context != null) {
                swagger = (Swagger) context.getAttribute("swagger");
            } else {
                swagger = new Swagger();
            }
            Set<Class<?>> classes = new HashSet<Class<?>>();
            if (scanner instanceof JaxrsScanner) {
                JaxrsScanner jaxrsScanner = (JaxrsScanner) scanner;
                classes = jaxrsScanner.classesFromContext(app, sc);
            } else {
                classes = scanner.classes();
            }
            if (classes != null) {
                Reader reader = new Reader(swagger);
                swagger = reader.read(classes);
                if (scanner instanceof SwaggerConfig)
                    swagger = ((SwaggerConfig) scanner).configure(swagger);
                else {
                    SwaggerConfig configurator = (SwaggerConfig) context
                            .getAttribute("reader");
                    if (configurator != null) {
                        LOGGER.debug("configuring swagger with " + configurator);
                        configurator.configure(swagger);
                    } else
                        LOGGER.debug("no configurator");
                }

            }
        }
        initialized = true;
        return swagger;
    }

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    @Path("/swagger.json")
    @ApiOperation(value = "The swagger definition in JSON", hidden = true)
    public Response getListingJson(@Context Application app,
            @Context ServletConfig sc, @Context HttpHeaders headers,
            @Context UriInfo uriInfo) {
        if (!initialized)
            swagger = scan(app, sc);
        if (swagger != null) {
            SwaggerSpecFilter filterImpl = FilterFactory.getFilter();
            if (filterImpl != null) {
                SpecFilter f = new SpecFilter();
                swagger = f.filter(swagger, filterImpl,
                        getQueryParams(uriInfo.getQueryParameters()),
                        getCookies(headers), getHeaders(headers));
            }
            return Response.ok().entity(swagger).build();
        } else
            return Response.status(404).build();
    }

    @GET
    @Produces("application/yaml")
    @Path("/swagger.yaml")
    @ApiOperation(value = "The swagger definition in YAML", hidden = true)
    public Response getListingYaml(@Context Application app,
            @Context ServletConfig sc, @Context HttpHeaders headers,
            @Context UriInfo uriInfo) {
        // Swagger swagger = (Swagger) context.getAttribute("swagger");
        if (!initialized)
            swagger = scan(app, sc);
        try {
            if (swagger != null) {
                SwaggerSpecFilter filterImpl = FilterFactory.getFilter();
                LOGGER.debug("using filter " + filterImpl);
                if (filterImpl != null) {
                    SpecFilter f = new SpecFilter();
                    swagger = f.filter(swagger, filterImpl,
                            getQueryParams(uriInfo.getQueryParameters()),
                            getCookies(headers), getHeaders(headers));
                }

                String yaml = Yaml.mapper().writeValueAsString(swagger);
                String[] parts = yaml.split("\n");
                StringBuilder b = new StringBuilder();
                for (String part : parts) {
                    int pos = part.indexOf("!<");
                    int endPos = part.indexOf(">");
                    b.append(part);
                    b.append("\n");
                }
                return Response.ok().entity(b.toString()).type("text/plain")
                        .build();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return Response.status(404).build();
    }

    protected Map<String, List<String>> getQueryParams(
            MultivaluedMap<String, String> params) {
        Map<String, List<String>> output = new HashMap<String, List<String>>();
        if (params != null) {
            for (String key : params.keySet()) {
                List<String> values = params.get(key);
                output.put(key, values);
            }
        }
        return output;
    }

    protected Map<String, String> getCookies(HttpHeaders headers) {
        Map<String, String> output = new HashMap<String, String>();
        if (headers != null) {
            for (String key : headers.getCookies().keySet()) {
                Cookie cookie = headers.getCookies().get(key);
                output.put(key, cookie.getValue());
            }
        }
        return output;
    }

    protected Map<String, List<String>> getHeaders(HttpHeaders headers) {
        Map<String, List<String>> output = new HashMap<String, List<String>>();
        if (headers != null) {
            for (String key : headers.getRequestHeaders().keySet()) {
                List<String> values = headers.getRequestHeaders().get(key);
                output.put(key, values);
            }
        }
        return output;
    }
}

[ralf0131]

I am using swagger on Jersey based RESTful service, onr service simply runs on JDK HttpServer so there is no chance to get context injected into ApiListResource. Therefore NPE will be thrown in line 90 if accessing /swagger.json:

Swagger swagger = (Swagger) context.getAttribute("swagger");

configuration:

<dependency>
            <groupId>io.swagger</groupId>
            <artifactId>swagger-jersey2-jaxrs</artifactId>
            <version>1.5.0</version>
        </dependency>

I am +1 on not relying on ServletContext to initialize swagger instance.
I checked the source code in v1.5.4 and develop-2.0 branch, which has still not beeb fixed.
Is there plan about when to fix it?

[fehguy]

I suggest you send a PR then, you can even base it on the previous comments.

[ralf0131]

Thanks for your comments. I will send out a PR later.

[ralf0131]

Hi @fehguy I've filed the PR. Could you please take some time to review it?

[frantuma]

fixed in #1611