如何使用Spring Boot 1.5.2注入Jersey终结点接口的实现? [英] How to use Spring Boot 1.5.2 to inject implementations of Jersey endpoint interfaces?

问题描述

在Spring Boot 1.5.2上，我正在缩减包含Web服务的大型Web应用程序，使其仅成为Jersey Web Service.因为该Web服务已经具有由Apache Wink实现的一整套JAX-RS批注，所以我决定使用Spring + Jersey而不是Spring Rest.我发现了这个 spring -boot-jersey-sample 应用程序作为参考.我正在处理的应用程序和示例之间的最大区别是，我的端点定义在接口和实现之间划分.

I am scaling back a large web application that included a web service to become only a Jersey web service, on Spring Boot 1.5.2. Because the web service already had a complete set of JAX-RS annotations implemented by Apache Wink, I decided to go with Spring + Jersey instead of Spring Rest. I found this spring-boot-jersey-sample application to use as a reference. The biggest difference between the application I'm working on and the sample is that my endpoint definitions are divided between interfaces and implementations.

我在pom.xml中添加了以下内容:

I added the following to my pom.xml:

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jersey</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>

我的新Jersey Config看起来像这样:

My new Jersey Config looks like this:

package com.example.configuration;

import org.glassfish.jersey.server.ResourceConfig;
import com.example.EndpointImpl;
import org.springframework.stereotype.Component;

@Component
public class JerseyConfiguration extends ResourceConfig {
  public JerseyConfiguration() {
    registerEndpoints();
  }

  private void registerEndpoints() {
    register(EndpointImpl.class);     
  }
}

然后我有以下Application.java:

Then I have the following Application.java:

package com.example;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
public class Application extends SpringBootServletInitializer{
  public static void main(String[] args) {
    new Application().configure(new SpringApplicationBuilder(Application.class)).run(args);
  }
}

将端点定义为接口和实现，如下所示(减去导入):

The endpoints are defined as an interface and an implementation, like this (minus imports):

public interface Endpoint {
  @GET
  @Produces({MediaType.APPLICATION_JSON})
  public Response getHello(@Context ServletContext sc, @Context HttpServletRequest req, @Context HttpHeaders httpHeaders) ;
}

@Path("")
@Component
public class EndpointImpl implements Endpoint {
  @Override
  public Response getHello(@Context ServletContext sc, @Context HttpServletRequest req,
      @Context HttpHeaders httpHeaders)  {
      return Response.ok("hello").build();
  }
}

启动应用程序时，我看到消息说Tomcat已经启动，包括显示Mapping servlet: 'com.example.configuration.JerseyConfiguration' to [/*]的消息.但是，当我使用Web浏览器访问/时，出现404 Not Found错误.看起来GET定义似乎没有被采用.

When I start up my application, I see messages saying Tomcat has started up, including a messges saying Mapping servlet: 'com.example.configuration.JerseyConfiguration' to [/*]. However, when I go to / with a web browser, I get a 404 Not Found error. It doesn't look like the GET definition is getting picked up.

推荐答案

此问题在 JAX-RS规范.

JAX-RS批注可以用于超类或已实现接口的方法和方法参数.此类注释由相应的子类或实现类方法继承，前提是该方法及其参数自己没有任何JAX-RS注释.

如果子类或实现方法具有任何JAX-RS批注，则将忽略超类或接口方法上的所有批注.例如:

public interface ReadOnlyAtomFeed {
  @GET @Produces("application/atom+xml")
  Feed getFeed();
}

@Path("feed")
public class ActivityLog implements ReadOnlyAtomFeed {
  public Feed getFeed() {...}
}

在上面，ActivityLog.getFeed从接口继承了@GET和@Produces批注.

In the above, ActivityLog.getFeed inherits the @GET and @Produces annotations from the interface.

相反:

@Path("feed")
public class ActivityLog implements ReadOnlyAtomFeed {
  @Produces("application/atom+xml")
  public Feed getFeed() {...}
}

在上文中，ReadOnlyAtomFeed.getFeed上的@GET批注未被ActivityLog.getFeed继承，并且由于它重新定义了@Produces批注，因此将需要其自己的请求方法标识符(@GET). /strong>

In the above, the @GET annotation on ReadOnlyAtomFeed.getFeed is not inherited by ActivityLog.getFeed and it would require its own request method designator (@GET) since it redefines the @Produces annotation.

为了与其他Java EE规范保持一致，建议始终重复注释，而不要依赖注释继承.

For consistency with other Java EE specifications, it is recommended to always repeat annotations instead of relying on annotation inheritance.

我强调了重要的端口.应该很清楚为什么它不适合您.在您的EndpointImpl中，您重复了@Context注释，因此导致超类或接口方法上的所有注释都将被忽略" .这包括@GET.因此最终，由于端点需要@METHOD

I've highlighted the important ports. It should be pretty clear why it isn't working for you. In your EndpointImpl, you have repeated the @Context annotations, therefore causing "all of the annotations on the superclass or interface method are ignored". This include the @GET. So ultimately, this causes that endpoint not to be registered, as endpoints require a @METHOD.

对于块引用中的最后一段，您可以选择是否遵循.我只是为了完整性而把它扔在那里.

As far as the last paragraph in the blockquote, you can choose to follow it or not. I just threw it in there just for completeness.

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