试图将xml解组到对象时出现NullPointerException

Question

我一直试图将xml（作为字符串）解组到一个对象，但它返回了一个NullPointerException错误。我花了一周时间寻找解决方案，但似乎什么都没用。我已经多次修改了“unmarshallpacs008”方法和“Spienvelessage”类，尝试了我在论坛上找到的其他东西。

在调试代码时，我看到错误发生在“unmarshaller.unmarshal”点，在该点上，“SpinevelMessage”类中存在的所有2个元素都返回null。它们的返回方式如下图所示，但我已经更改了@XmlElement的名称和属性，没有任何效果。

appHdr=null文档=null

抛出错误的点在“message.getDocument（）......”bc没有文档，因为它返回null（PSPEmissorService的第94行）

java.lang.NullPointerException: null
    at com.praxis.spi_simulator.psp_emissor.application.services.PSPEmissorService.sendPaymentsToSpi(PSPEmissorService.java:94) ~[classes/:na]
    at com.praxis.spi_simulator.psp_emissor.application.controller.PSPEmissorController.sendPaymentsToSpiIssuer(PSPEmissorController.java:70) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197) ~[spring-web-5.3.5.jar:5.3.5]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141) ~[spring-web-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:894) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1060) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:962) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) ~[tomcat-embed-core-9.0.44.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.5.jar:5.3.5]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.44.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.5.jar:5.3.5]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.5.jar:5.3.5]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.5.jar:5.3.5]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.5.jar:5.3.5]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.5.jar:5.3.5]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.3.5.jar:5.3.5]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1707) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.44.jar:9.0.44]
    at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]

SPIEnvelopeMessage message = XMLUtil.unmarshallpacs008(xml);
                idLongStr = ("" + idLong).length() < SimulatorConstants.TAMANIO_COMPLEMENTO ? "0" + idLong : "" + idLong;
                message.getDocument().getFIToFICstmrCdtTrf().getGrpHdr().setMsgId(idSufijo + idLongStr);
                message.getAppHdr().setBizMsgIdr(idSufijo + idLongStr);

@XmlRootElement(name = "Envelope")
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "SPIEnvelopeMessage", propOrder = {
    "appHdr",
    "document"
})
public class SPIEnvelopeMessage {

    @XmlElement(name = "AppHdr", required = true)
    protected SPIHead00100101 appHdr;
    @XmlElement(name = "Document", required = true)
    protected SPIPacs00800109 document;

    /**
     * Obtiene el valor de la propiedad appHdr.
     * 
     * @return
     *     possible object is
     *     {@link SPIHead00100101 }
     *     
     */
    public SPIHead00100101 getAppHdr() {
        return appHdr;
    }

    /**
     * Define el valor de la propiedad appHdr.
     * 
     * @param value
     *     allowed object is
     *     {@link SPIHead00100101 }
     *     
     */
    public void setAppHdr(SPIHead00100101 value) {
        this.appHdr = value;
    }

    /**
     * Obtiene el valor de la propiedad document.
     * 
     * @return
     *     possible object is
     *     {@link SPIPacs00800109 }
     *     
     */
    public SPIPacs00800109 getDocument() {
        return document;
    }

    /**
     * Define el valor de la propiedad document.
     * 
     * @param value
     *     allowed object is
     *     {@link SPIPacs00800109 }
     *     
     */
    public void setDocument(SPIPacs00800109 value) {
        this.document = value;
    }

}

@SuppressWarnings("unchecked")
    public static SPIEnvelopeMessage unmarshallpacs008(String xml)
            throws JAXBException {
        StringReader sr = new StringReader(xml);
        JAXBContext jc = JAXBContext.newInstance(SPIEnvelopeMessage.class);
        Unmarshaller unmarshaller = jc.createUnmarshaller();
        return (SPIEnvelopeMessage) ((JAXBElement) unmarshaller.unmarshal(sr)).getValue();
    }

Answer 1

要列表一个对象，您必须确保该对象以及该对象的内容是可序列化的。

尝试在您的类中实现Serializable接口：

public SPIEnvelopeMessage implements Serializable {}