为什么 jersey 状态为 500 时没有错误日志？

Question

这是我的 web.xml：

<servlet>
  <servlet-name>Jersey REST Service</servlet-name>
  <servlet-class>
    org.glassfish.jersey.servlet.ServletContainer
  </servlet-class>
  <init-param>
    <param-name>jersey.config.server.provider.packages</param-name>
    <param-value>rest</param-value>
  </init-param>
  <init-param>
    <param-name>jersey.config.server.provider.classnames</param-name>
    <param-value>org.glassfish.jersey.filter.LoggingFilter</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>

这是我的资源类：

@Path("/main")
public class MainResource {

    @XmlRootElement
    public class Planet {
        public int id;
        public String name;
        public double radius;
    }

    @GET
    @Produces(MediaType.APPLICATION_XML)
    public Planet getPlanet() {
        final Planet planet = new Planet();

        planet.id = 1;
        planet.name = "Earth";
        planet.radius = 1.0;

        return planet;
    }
}

而当我运行tomcat服务器时，日志是这样的：

09-Jan-2015 13:19:10.501 INFO [http-apr-8080-exec-8] org.glassfish.jersey.filter.LoggingFilter.log 1 * Server has received a request on thread http-apr-8080-exec-8
1 > GET http://localhost:8080/rest/main
1 > accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
1 > accept-encoding: gzip, deflate, sdch
1 > accept-language: en,zh-CN;q=0.8,zh;q=0.6
1 > connection: keep-alive
1 > cookie: JSESSIONID=69F79D567E7ECA27A129C477B91C7758
1 > host: localhost:8080
1 > user-agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36

09-Jan-2015 13:19:10.597 INFO [http-apr-8080-exec-8] org.glassfish.jersey.filter.LoggingFilter.log 1 * Server responded with a response on thread http-apr-8080-exec-8
1 < 200
1 < Content-Type: application/xml

09-Jan-2015 13:19:10.794 INFO [http-apr-8080-exec-8] org.glassfish.jersey.filter.LoggingFilter.log 2 * Server responded with a response on thread http-apr-8080-exec-8
2 < 500

我想知道为什么它显示 500 错误，但我找不到任何关于异常堆栈的错误日志。

请帮帮我。

Answer 1

我解决了我的问题，现在我回答我自己的问题。

首先，如何启用异常跟踪日志记录？

@Provider
public class ExceptionMapper implements javax.ws.rs.ext.ExceptionMapper<Exception> {
    @Override
    public Response toResponse(Exception exception) {
        exception.printStackTrace();
        return Response.status(500).build();
    }
}

是的，我们应该自己实现一个 ExceptionMapper。

第二，我的代码有什么错误？

Planet 类应该是静态的。