Java Web 服务客户端在调用 Web 方法时发生 NullPointerException

Question

每当我从 Web 服务调用方法时，客户端都会收到 NullPointerException。

这些是我从测试中得到的结果：

工具 "SoapUI" 表明 WebService 有效并且 returns 预期值
None的变量是null
WebService 的返回值似乎没有到达客户端
客户端成功连接到WebService

异常：

javafx.fxml.LoadException: 
... Not Important ...
Caused by: java.lang.NullPointerException
at com.sun.xml.internal.bind.v2.ClassFactory.create0(Unknown Source)
at com.sun.xml.internal.bind.v2.ClassFactory.create(Unknown Source)
at com.sun.xml.internal.bind.v2.runtime.reflect.Lister$CollectionLister.startPacking(Unknown Source)
at com.sun.xml.internal.bind.v2.runtime.reflect.Lister$CollectionLister.startPacking(Unknown Source)
at com.sun.xml.internal.bind.v2.runtime.reflect.NullSafeAccessor.get(Unknown Source)
at com.sun.xml.internal.bind.v2.runtime.reflect.Accessor.getUnadapted(Unknown Source)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.get(Unknown Source)
at com.sun.xml.internal.ws.db.glassfish.RawAccessorWrapper.get(Unknown Source)
at com.sun.xml.internal.ws.client.sei.ResponseBuilder$DocLit$PartBuilder.readResponse(Unknown Source)
at com.sun.xml.internal.ws.client.sei.ResponseBuilder$DocLit.readResponse(Unknown Source)
at com.sun.xml.internal.ws.client.sei.StubHandler.readResponse(Unknown Source)
at com.sun.xml.internal.ws.db.DatabindingImpl.deserializeResponse(Unknown Source)
at com.sun.xml.internal.ws.db.DatabindingImpl.deserializeResponse(Unknown Source)
at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(Unknown Source)
at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(Unknown Source)
at com.sun.xml.internal.ws.client.sei.SEIStub.invoke(Unknown Source)
at com.sun.proxy.$Proxy40.getOnlineUser(Unknown Source)
at application.Controller.init(Controller.java:141)
at application.Controller.initialize(Controller.java:74)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 17 more

我的网络服务：

    @WebService
    @SOAPBinding(style = javax.jws.soap.SOAPBinding.Style.DOCUMENT, use=javax.jws.soap.SOAPBinding.Use.LITERAL, parameterStyle=javax.jws.soap.SOAPBinding.ParameterStyle.WRAPPED)
    public interface CClientService {
      public ObservableList<Benutzer> getOnlineUser(int id);
    }

我的 Web 服务实现：

@WebService
public class CClientServiceImpl implements CClientService {
private BenutzerService benutzerService;
private Notification notification;

    @Override
    public ObservableList<Benutzer> getOnlineUser(int id) {
        return benutzerService.getAllOnlineBenutzerWithoutMe(id);
    }
}

我的通知：

public class Notification extends Observable {

@Override
public synchronized void addObserver(Observer o) {
    notifyTheObservers(o);
    super.addObserver(o);
}

@Override
public synchronized void deleteObserver(Observer o) {
    super.deleteObserver(o);
    notifyTheObservers(o);
}

public void notifyTheObservers(Object arg){
    setChanged();
    super.notifyObservers(arg);
}

}

我的 BenutzerService：

public class BenutzerService extends Repository<Benutzer> {

    public ObservableList<Benutzer> getAllOnlineBenutzerWithoutMe(int id){
       ObservableList<Benutzer> listeAllerBenutzer = FXCollections.observableArrayList();
       listeAllerBenutzer.setAll(em.createNamedQuery("Benutzer.findAllOnlineWithoutMe",Benutzer.class).setParameter("b_id", id).getResultList());
       return listeAllerBenutzer;
    }
}

我的存储库：

public abstract class Repository<T> {
   protected EntityManagerFactory emf = Persistence.createEntityManagerFactory("unitname");
   protected EntityManager em = emf.createEntityManager();

   abstract public void create(T object);
   abstract public void update(T object);
   abstract public void delete(T object);
   abstract public T findById(int id);
   abstract public ObservableList<T> getAll();
}

我的客户：

public class CClient implements Observer {
private Client client;
private final String host = "localhost";
private final String port = "8080";
private final String path = "MyCoolPath?wsdl";
private CClientService cclientService;
public CClient(){
    client = new Client();
    this.cclientService = getService();
}

public Client getClient() {
    return client;
}

@Override
public void update(Observable o, Object arg) {
    switch(arg.getClass().getSimpleName()){
        case "String":
            System.out.println("Got it, my String.");
            break;
        default:
            System.out.println(arg.getClass().getSimpleName()+"<<<<<<<<");
            break;
    }
}

private CClientService getService(){
    URL urlAdresse = null;
    try {
        urlAdresse = new URL("http://"+ host + ":"+ port + "/" + path);
    } catch (MalformedURLException e) {
        System.out.println("No Connection!");
        e.printStackTrace();
    }

    QName qnameService = new QName("http://webservice/",
            "CClientServiceImplService");
    QName qnamePort = new QName("http://webservice/",
            "CClientServiceImplPort");

    Service service = Service.create(urlAdresse,qnameService);
    CClientService ws = service.getPort(qnamePort,CClientService.class);

    return ws;
}

public CClientService getCclientService() {
    return this.cclientService;
}
}

Web 服务和客户端在不同的项目中。

Answer 1

首先，我将注释 @WebService 从我的 "CClientServiceImpl.class" 更改为 @WebService(endpointInterface="webservice.CClientService")，因为我意识到 System.out.println(ws.get...().size()); 我得到了错误消息 "Unkown Port"，在我更改注释后 "Unknown Port" 错误已解决。

问题是，我想 return 一个 "ObservableList"... 我将其更改为 "List"（在 "CClientServiceImpl.class" 和 "BenutzerService.class"）问题解决了......我检查了一切，但没有尝试如果我得到正常的 java.util.List.

会发生什么

所以我的 WebService 接口方法如下所示：

public List<Benutzer> getOnlineUser(int id);

和这样的实现：

@Override
public List<Benutzer> getOnlineUser(int id) {
    return benutzerService.getAllOnlineBenutzerWithoutMe(id);
}

最后我的服务改成了这样：

public List<Benutzer> getAllOnlineBenutzerWithoutMe(int id){
    List<Benutzer> listeAllerBenutzer = FXCollections.observableArrayList();
    listeAllerBenutzer = (em.createNamedQuery("Benutzer.findAllOnlineWithoutMe",Benutzer.class).setParameter("b_id", id).getResultList());
    return listeAllerBenutzer;
}

Java Web 服务客户端在调用 Web 方法时发生 NullPointerException

Java Web Service Client NullPointerException on calling a Web Method

java

web-services

webservice-client