返回导致 500 的 javax.ws.rs.core.Response 列表答案

【问题标题】：Returning a list of javax.ws.rs.core.Response resulting in 500返回导致 500 的 javax.ws.rs.core.Response 列表
【发布时间】：2016-11-30 10:00:56
【问题描述】：

我正在尝试从我的休息端点返回一个响应对象的 ArrayList。

为此，我将我的结果集包装在一个通用实体对象中

try {
    GenericEntity<List<Response>> response = new GenericEntity<List<Response>>(responses) {
    };
    return Response.ok(response).build();
} catch (Exception e) {
    e.printStackTrace();
}

无论我尝试什么，我都会得到 500 的回报，这令人沮丧。有没有办法让我得到一个更明确的答案来解释为什么会失败？我的方法使用的注解如下；

@POST
@Path("restendpoint")
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)

谢谢

编辑

添加自定义异常映射器后，我可以看到错误是因为这个

javax.ws.rs.WebApplicationException: HTTP 500 Internal Server Error
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:951)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:265)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:250)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:106)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:86)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1130)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:711)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:444)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:434)
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:329)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:769)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1125)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1059)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
    at org.eclipse.jetty.server.Server.handle(Server.java:497)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:248)
    at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:610)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:539)
    at java.lang.Thread.run(Thread.java:744)
Caused by: javax.xml.bind.MarshalException
 - with linked exception:
[Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class org.glassfish.jersey.message.internal.OutboundJaxrsResponse was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.]
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:487)
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:949)
    ... 40 more
Caused by: Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class org.glassfish.jersey.message.internal.OutboundJaxrsResponse was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.
    at org.eclipse.persistence.exceptions.XMLMarshalException.descriptorNotFoundInProject(XMLMarshalException.java:154)
    at org.eclipse.persistence.internal.oxm.Context$ContextState.getSession(Context.java:137)
    at org.eclipse.persistence.oxm.XMLContext$XMLContextState.getSession(XMLContext.java:798)
    at org.eclipse.persistence.oxm.XMLContext$XMLContextState.getSession(XMLContext.java:1)
    at org.eclipse.persistence.internal.oxm.Context.getSession(Context.java:458)
    at org.eclipse.persistence.oxm.XMLContext.getSession(XMLContext.java:366)
    at org.eclipse.persistence.oxm.XMLContext.getSession(XMLContext.java:1)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:582)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshalStreamOrWriter(XMLMarshaller.java:1126)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:934)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:877)
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:483)
    ... 41 more

【问题讨论】：

这是因为 moxy 不知道如何将 List 序列化为 Json。一种简单的解决方法是改用 JSON-P 并自行处理序列化。在 JavaEE 8 中，它将被标准化（JSR 367）

标签： java web-services rest http jax-rs

【解决方案1】：

正如@simdevmon 所说，javax.ws.rs.core.Response 不适合您的目的，因为一旦您调用build() 方法，它将创建一个传出响应 (OutboundJaxrsResponse)，Jersey 使用该响应发送给客户。

这意味着默认情况下，当通过服务器发送响应时，Jersey 不会理解如何编组/解组其属性。

如果您只需要响应对象列表作为 JSON 结果，另一种合适的解决方案是为您的列表创建一个包装类（没有最终字段或构造函数）：

import javax.ws.rs.core.Response;

public class MyResponse {

    private List<Response> responses;

    public List<Response> getResponses() {
        return responses;
    }

    public void setResponses(List<Response> responses) {
        this.responses = responses;
    }

}

你的其余调用来处理这个对象：

try {
    List<Response> responses = new ArrayList<>();
    responses.add(Response.ok().build());
    responses.add(Response.notModified().build());
    responses.add(Response.noContent().build());

    MyResponse myResponse = new MyResponse();
    myResponse.setResponses(responses);

    return Response.ok(new GenericEntity<MyResponse>(myResponse) {}).build();
} catch (Exception e) {
    e.printStackTrace();
}

这将生成以下 JSON 输出：

{
  "responses": [
    "OutboundJaxrsResponse{status=200, reason=OK, hasEntity=false, closed=false, buffered=false}",
    "OutboundJaxrsResponse{status=304, reason=Not Modified, hasEntity=false, closed=false, buffered=false}",
    "OutboundJaxrsResponse{status=204, reason=No Content, hasEntity=false, closed=false, buffered=false}"
  ]
}

【讨论】：

【解决方案2】：

您还可以执行以下操作（注意 jersey-media-json-jackson 的依赖项），这是额外添加的以使 List 返回工作

代码：

@GET
    @Path("getListRes") 
    @Produces("application/json")
    public Response getListResponse() {

        List<Response> responses = new ArrayList<>();
        responses.add(Response.ok().build());
        responses.add(Response.notModified().build());
        responses.add(Response.noContent().build());
        GenericEntity<List> list = new GenericEntity<List> (responses) {}; 
        return Response.status(200).entity(list).build();

    }

Pom.xml 依赖

<!-- Jersey 2.19 -->
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
            <version>${jersey2.version}</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-server</artifactId>
            <version>${jersey2.version}</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-client</artifactId>
            <version>${jersey2.version}</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.2.4</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-jackson</artifactId>
            <version>2.24.1</version>
        </dependency>

输出：http://jerseyexample-ravikant.rhcloud.com/rest/jws/getListRes

【讨论】：