Столкновение с NullPointerException в веб-приложении Джерси, если я использую @Produces (MediaType.APPLICATION_ XML)

Question

Я сталкиваюсь с NullPointerException при попытке вернуть непустой объект класса с помощью @ Produces (MediaType.APPLICATION_ XML) . Для MediaType.APPLICATION_ JSON и MediaType.TEXT_PLAIN не будет работать при возврате объекта. Если возвращается только строка, то он работает.

Ниже приведены мои файлы:

• Alien. java

package com.akshay.DemoRest;

import jakarta.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Alien {
    private String name;
    private int points;

    public Alien() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPoints() {
        return points;
    }

    public void setPoints(int points) {
        this.points = points;
    }

}

• AlienController . java

package com.akshay.DemoRest;

import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.core.MediaType;

@Path("aliens")
public class AlienController {

    @GET
    @Produces(MediaType.APPLICATION_XML)
    public Alien getAlien() {
        Alien alien1 = new Alien();
        alien1.setName("Akshay");
        alien1.setPoints(10);
        return alien1;
    }
}

• пом. xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.akshay</groupId>
    <artifactId>DemoRest</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>DemoRest</name>

    <build>
        <finalName>DemoRest</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <inherited>true</inherited>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.glassfish.jersey</groupId>
                <artifactId>jersey-bom</artifactId>
                <version>${jersey.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet-core</artifactId>
            <!-- use the following artifactId if you don't need servlet 2.x compatibility -->
            <!-- artifactId>jersey-container-servlet</artifactId -->
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.inject</groupId>
            <artifactId>jersey-hk2</artifactId>
        </dependency>
        <!-- uncomment this to get JSON support
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-binding</artifactId>
        </dependency>
        -->
    </dependencies>
    <properties>
        <jersey.version>3.0.0-M1</jersey.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
</project>

• полотно. xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- This web.xml file is not required when using Servlet 3.0 container,
     see implementation details http://jersey.java.net/nonav/documentation/latest/jax-rs.html -->
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <servlet>
        <servlet-name>Jersey Web Application</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>com.akshay.DemoRest</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Jersey Web Application</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

Ошибка консоли -

May 28, 2020 6:05:11 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Jersey Web Application] in context with path [/DemoRest] threw exception [java.lang.NullPointerException] with root cause
java.lang.NullPointerException
    at jakarta.xml.bind.ContextFinder.handleClassCastException(ContextFinder.java:114)
    at jakarta.xml.bind.ContextFinder.newInstance(ContextFinder.java:254)
    at jakarta.xml.bind.ContextFinder.newInstance(ContextFinder.java:240)
    at jakarta.xml.bind.ContextFinder.find(ContextFinder.java:375)
    at jakarta.xml.bind.JAXBContext.newInstance(JAXBContext.java:691)
    at jakarta.xml.bind.JAXBContext.newInstance(JAXBContext.java:632)
    at org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getStoredJaxbContext(AbstractJaxbProvider.java:288)
    at org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getJAXBContext(AbstractJaxbProvider.java:273)
    at org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getMarshaller(AbstractJaxbProvider.java:240)
    at org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getMarshaller(AbstractJaxbProvider.java:207)
    at org.glassfish.jersey.jaxb.internal.AbstractRootElementJaxbProvider.writeTo(AbstractRootElementJaxbProvider.java:151)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:242)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:227)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:139)
    at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:85)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:139)
    at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:61)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:139)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1116)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:638)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:371)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:361)
    at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:256)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:244)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:265)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:232)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:680)
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:394)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:346)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:366)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:319)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:205)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:688)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)