远程对象不支持 RMI 方法：java.rmi.UnmarshalException：无法识别的方法哈希答案

【问题标题】：RMI Method not supported by remote object: java.rmi.UnmarshalException: unrecognized method hash远程对象不支持 RMI 方法：java.rmi.UnmarshalException：无法识别的方法哈希
【发布时间】：2016-10-17 19:16:02
【问题描述】：

我的银行 - 客户端（通过 RMI 的服务器客户端）应用程序遇到了一个奇怪的问题。

我有实现 IBank 的 Bank 类扩展 Remote。这个银行类有几个方法，checkClient、getBankAccount 等。

问题是，我可以从客户端调用方法 checkClient (boolean) 就好了，所有其他方法都会给出 UnmarshalException

服务器端的银行类：

public class Bank extends UnicastRemoteObject implements IBank { 

    private BankName bankName;

    private String URL;

    @Override
    public boolean checkClient(String username, String password) {
        Client client = db.getClient(username, password);

        if(client.getUsername() == null && client.getPassword() == null){
        System.out.println("Client not found in " + getBankName() + "database");
            return false;
        }

        System.out.println(client.toString() + " connected to bank succesfully");

        return true;
    }

    @Override
    public ArrayList<BankAccount> getAccounts(Client c) throws RemoteException {
       System.out.println("WORKED");
       return null;
    }
}

银行类实现的接口：

public interface IBank extends Remote{

    String getURL() throws RemoteException;

    String getBankName() throws RemoteException;

    boolean checkClient(String Username, String Password) throws RemoteException;

    ArrayList<BankAccount> getAccounts(Client c) throws RemoteException;
}

Bankmethod 使用的可序列化对象：

public class BankAccount implements Serializable {

}

*以上示例只是完整应用程序的一部分

我无法弄清楚为什么“checkClient”方法工作得很好，而 getAccounts（以及上面代码中未包含的其他方法）会给出 UnmarshalException。

任何帮助将不胜感激

示例

您可以在下面找到我用来将客户连接到银行的方法：

@Override
public

ArrayList<BankAccount> connectToBank(Client c) throws RemoteException {
    assert(c != null);

    ArrayList<BankAccount> accounts;        

    if(!Bank.checkClient(c.Username, c.Password)){
        System.out.println("bank.checkclient == false, Client not found");
        return null;
    } else {
        System.out.println("Client found in " + Bank.getBankName() + " database");
    }

    System.out.println("Calling bank.getaccounts");
    accounts = Bank.getAccounts(c);

    if(accounts == null){
        System.out.println("No accounts found for " + c.Username);
    }

    return accounts;        
}

当我使用不存在的用户名和密码时，控制台会打印出来：

Server IP Address: localhost
Server Port number 9000
Client: Registry located
Client: Bank and Publisher are bound
bank.checkclient == false, Client not found

并返回null；

但是，当我使用确实存在的用户名和密码时，控制台会打印出：

Server IP Address: localhost
Server Port number 9000
Client: Registry located
Client: Bank and Publisher are bound
Client found in RABO database
Calling bank.getaccounts
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8411)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.keyReleased(ButtonBehavior.java:136)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.callAction(ButtonBehavior.java:106)
    at com.sun.javafx.scene.control.behavior.BehaviorBase.callActionForEvent(BehaviorBase.java:218)
    at com.sun.javafx.scene.control.behavior.BehaviorBase.lambda$new$74(BehaviorBase.java:135)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$KeyHandler.process(Scene.java:3964)
    at javafx.scene.Scene$KeyHandler.access$1800(Scene.java:3910)
    at javafx.scene.Scene.impl_processKeyEvent(Scene.java:2040)
    at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:2501)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:197)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(GlassViewEventHandler.java:147)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$353(GlassViewEventHandler.java:228)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:227)
    at com.sun.glass.ui.View.handleKeyEvent(View.java:546)
    at com.sun.glass.ui.View.notifyKey(View.java:966)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
    ... 49 more
Caused by: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: unrecognized method hash: method not supported by remote object
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:354)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$256(TCPTransport.java:683)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
    at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:276)
    at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:253)
    at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:162)
    at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:227)
    at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:179)
    at com.sun.proxy.$Proxy7.getAccounts(Unknown Source)
    at Client.Client.connectToBank(Client.java:240)
    at Client.FXMLClientController.btnLogIn_clicked(FXMLClientController.java:232)
    ... 59 more
Caused by: java.rmi.UnmarshalException: unrecognized method hash: method not supported by remote object
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$256(TCPTransport.java:683)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    ... 1 more

所以你可以看到 Bank.checkClient 工作正常，Bank.getAccounts 导致了问题

【问题讨论】：

接口银行账户？
提示：考虑添加一些异常堆栈跟踪。除非您告诉我们，否则这里没有人有水晶球来了解您的应用程序在您的系统上做什么。
是的，乔普，已经尝试添加一个“IBankAccount 扩展远程”接口并让 BankAccount 实现它，但这并没有解决问题。弹出相同的 UnmarshalException
嗯，真的是 all 调用失败了；还是您只是尝试了getAccounts() 一个？你看，对于getAccounts()，你的代码必须编组/传输/解组两个“非标准”类的对象——客户和银行账户。当然，如果这两个中的一个不序列化......那么你就会遇到问题。或者，如果涉及的具体类存在版本冲突。这就是为什么我们真的需要查看这些异常消息。
@GhostCatsalutesMonicaC。如果一个类不可序列化，你会看到一个不同的异常。

标签： java server rmi

【解决方案1】：

您在没有重新编译和重新部署所有内容的情况下更改了远程接口的某些内容。进行干净的构建、重新部署、重新测试。

【讨论】：

【解决方案2】：

我仍然没有弄清楚确切的问题，但是当我尝试通过 RMI 发送自定义对象时，问题才出现。从银行返回字符串、布尔值、整数等的方法运行良好。当我尝试发送 BankAccount (customobject) 时，出现了问题。

我通过将 Client-project 和 Bank-project 合并在一起来修复它，现在它们使用完全相同的接口和类，因此 Unmarshal 问题消失了

希望这对某人有所帮助

【讨论】：

两天前我的回答中已经说明了确切的问题，您通过重新编译和重新部署来解决它，正如我的回答中所述。