Spring Boot Kotlin Jersey ModelValidationException

Question

我正在尝试让 Spring Boot + Jersey 与 Kotlin 一起使用。我配置了我通常在 Java 中使用的方式，但得到了以下堆栈跟踪。这似乎表明控制器被实例化了两次，但它不应该。

这是我的 JerseyConfig 类：

package com.joescodeshack.igdb.config

import com.fasterxml.jackson.module.kotlin.KotlinModule
import com.joescodeshack.igdb.controller.GenreController
import org.glassfish.jersey.server.ResourceConfig
import org.springframework.context.annotation.Bean
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder
import org.springframework.stereotype.Component
import javax.ws.rs.ApplicationPath

@Component
@ApplicationPath("/api")
open class JerseyConfig : ResourceConfig {

    constructor() {
        register(GenreController());
    }

    @Bean
    open fun objectMapperBuilder(): Jackson2ObjectMapperBuilder
            = Jackson2ObjectMapperBuilder().modulesToInstall(KotlinModule())
}

类型控制器（JAX-RS 端点）

package com.joescodeshack.igdb.controller

import com.joescodeshack.igdb.domain.Genre
import javax.ws.rs.GET
import javax.ws.rs.Path
import javax.ws.rs.Produces
import javax.ws.rs.core.MediaType
import javax.ws.rs.core.Response

@Path("/genre")
open class GenreController {

    val genres : List<Genre> = listOf(Genre(1,"Butt"), Genre(2, "Cow"))

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    open fun getGenres() : Response {
        return Response.ok(genres).build();
    }
}

堆栈跟踪：

2016-09-06 15:26:26.529 ERROR 17332 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[.[.j.i.c.JerseyConfig]    : Allocate exception for servlet com.joescodeshack.igdb.config.JerseyConfig

org.glassfish.jersey.server.model.ModelValidationException: Validation of the application resource model has failed during application initialization.
[[FATAL] A resource model has ambiguous (sub-)resource method for HTTP method GET and input mime-types as defined by"@Consumes" and "@Produces" annotations at Java methods public javax.ws.rs.core.Response com.joescodeshack.igdb.controller.GenreController.getGenres() and public final java.util.List com.joescodeshack.igdb.controller.GenreController.getGenres() at matching regular expression /genre. These two methods produces and consumes exactly the same mime-types and therefore their invocation as a resource methods will always fail.; source='org.glassfish.jersey.server.model.RuntimeResource@1b6cce78']
    at org.glassfish.jersey.server.ApplicationHandler.initialize(ApplicationHandler.java:555) ~[jersey-server-2.23.1.jar:na]
    at org.glassfish.jersey.server.ApplicationHandler.access$500(ApplicationHandler.java:184) ~[jersey-server-2.23.1.jar:na]
    at org.glassfish.jersey.server.ApplicationHandler$3.call(ApplicationHandler.java:350) ~[jersey-server-2.23.1.jar:na]
    at org.glassfish.jersey.server.ApplicationHandler$3.call(ApplicationHandler.java:347) ~[jersey-server-2.23.1.jar:na]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315) ~[jersey-common-2.23.1.jar:na]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297) ~[jersey-common-2.23.1.jar:na]
    at org.glassfish.jersey.internal.Errors.processWithException(Errors.java:255) ~[jersey-common-2.23.1.jar:na]
    at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:347) ~[jersey-server-2.23.1.jar:na]
    at org.glassfish.jersey.servlet.WebComponent.<init>(WebComponent.java:392) ~[jersey-container-servlet-core-2.23.1.jar:na]
    at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:177) ~[jersey-container-servlet-core-2.23.1.jar:na]
    at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:369) ~[jersey-container-servlet-core-2.23.1.jar:na]
    at javax.servlet.GenericServlet.init(GenericServlet.java:158) ~[tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1194) ~[tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:806) ~[tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:133) ~[tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:522) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:1110) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:785) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1425) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_102]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_102]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.4.jar:8.5.4]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_102]

Answer 1

问题在于以下属性：

val genres : List<Genre> = listOf(Genre(1,"Butt"), Genre(2, "Cow"))

生成一个在 JVM 级别具有以下签名的方法：

@NotNull
public final List<Genre> getGenres()

如您所见，它与控制器中的其他方法冲突。要解决它，请将属性更改为 private 或重命名其中一个方法。

附言。错误消息非常清楚地说明了问题：

public javax.ws.rs.core.Response com.joescodeshack.igdb.controller.GenreController.getGenres() 和 public final java.util.List com.joescodeshack.igdb.controller.GenreController.getGenres() 在 匹配正则表达式 /genre。这两种方法产生和 使用完全相同的 mime 类型，因此它们的调用与 资源方法总是会失败。;