[Jersey] RESTful service starter-kit (2)

如何設定Custom Injection

場景：
client發送get request，會在header帶一個userId，server會根據userId去資料庫查詢相關user．
例如：

1	curl -H 'userId: 89ce5a60-a88f-11e5-a837-0800200c9a66' http://localhost:8080/user

PS:正規的做法是把userId放在uri path中，這邊只是模擬從header抓取資料進行處理，之後可以透過annotation方式將結果放到resource

定義annotation

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})
public @interface UserParam {
}

定義ValueFactoryProvider

@Singleton
@Slf4j //lombok annotation
public final class UserParamValueFactoryProvider extends AbstractValueFactoryProvider {

  @Singleton
  public static final class InjectionResolver extends ParamInjectionResolver<UserParam> {
    public InjectionResolver() {
      super(UserParamValueFactoryProvider.class);
    }
  }

  @Inject
  public UserParamValueFactoryProvider(MultivaluedParameterExtractorProvider mpep, ServiceLocator injector) {
    super(mpep, injector, Parameter.Source.UNKNOWN);
  }

  @Override
  public AbstractContainerRequestValueFactory<?> createValueFactory(Parameter parameter) {
    Class<?> classType = parameter.getRawType();

    if (classType == null || (!classType.equals(User.class))) {
      log.warn("UserParam annotation was not placed on correct object type; Injection might not work correctly!");
      return null;
    }

    return new AbstractContainerRequestValueFactory<User> (){
      @Context
      private ResourceContext context;
      @Inject
      private Repo repo;

      public User provide() {
        final ContainerRequestContext context = this.context.getResource(ContainerRequestContext.class);
        final UUID                    userId  = UUID.fromString(context.getHeaderString("userId"));
        return repo.getUser(userId);
      }
    };
  }
}

Repo

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public interface Repo {
  User getUser(UUID uuid);
}

RepoFactory

public class RepoFactory implements Factory<Repo> {
  @Override
  public Repo provide() {
    return new DummyRepo();
  }

  @Override
  public void dispose(Repo instance) {

  }
}

bind UserParamValueFactoryProvider

bind(UserParamValueFactoryProvider.class).to(ValueFactoryProvider.class).in(Singleton.class);

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bind(UserParamValueFactoryProvider.InjectionResolver.class).to(new TypeLiteral<InjectionResolver<UserParam>>() {}).in(Singleton.class);
bindFactory(RepoFactory.class).to(Repo.class).in(Singleton.class);

透過annotation取得User

@GET
@ApiOperation(value = "Return user data", response = User.class)
public Response user(@NotNull @Valid @UserParam User user) {
  return Response.ok(user, MediaType.APPLICATION_JSON)
                 .build();
}

如何設定Swagger API

因為是透過ResourceConfig去設定JAX-RS，所以只要將以下程式碼加入到ResourceConfig就完成Swagger API設定

register(ApiListingResourceJSON.class);
register(SwaggerSerializers.class);

BeanConfig beanConfig = new BeanConfig();
beanConfig.setVersion("1.0.1");
beanConfig.setResourcePackage("rest"); // replace with your packages
beanConfig.setBasePath("http://localhost:8080/jersey-starterkit/");
beanConfig.setDescription("My RESTful resources");
beanConfig.setTitle("My RESTful API");
beanConfig.setFilterClass(ApiAuthorizationFilterImpl.class.getName());
beanConfig.setPrettyPrint(true);
beanConfig.setScan(true);

假如想要用apiKey限制使用者存取swagger.json，可以繼承SwaggerSpecFilter，在beanConfig.setFilterClass設定路徑即可．

呼叫swagger.json：

1	curl http://localhost:8080/swagger.json

程式碼：jersey-starterkit

如何設定Custom Injection

如何設定Swagger API

參考資料：