RMI UnmarshalException ClassNotFoundException 仅服务器

Question

我已经学习了几个关于运行 RMI 应用程序的教程。但是，我似乎无法让它工作，因为我一直卡在同一个异常上。

我目前只运行一个服务器，因此不涉及客户端通信。

我有一个简单的 RMI 程序，其中包括：

1. 一个服务器类SortServer
2. 一个接口ISortFactory<T>
3. 一个实现QuickSortFactory<T>
4. RMIUtils 类
5. 策略文件allpermissions.policy

政策文件内容

grant { 
    permission java.security.AllPermission;
};

RMIUtils

static {
    // Set policy
    setPolicy();

    // Set Security manager if not present
    if(System.getSecurityManager() == null) {
        System.setSecurityManager(new SecurityManager());
    }

    setHost("127.0.0.1");
}

public static void addCodeBaseFor(Class<?> clazz) {
    System.setProperty("java.rmi.server.codebase", clazz.getProtectionDomain().getCodeSource().getLocation().toString());
}

public static void setPolicy() {
    System.setProperty("java.security.policy", PolicyFileLocator.getLocationOfPolicyFile());
}

public static void setHost(String hostAddress) {
    System.setProperty("java.rmi.server.hostname", hostAddress);
}

public static String getHost() {
    return System.getProperty("java.rmi.server.hostname");
}

排序服务器

public static void main(String[] args) throws RemoteException, MalformedURLException, AlreadyBoundException {
    RMIUtils.addCodeBaseFor(ISortFactory.class);

    ISortFactory<String> strQSFactory = new QuickSortFactory<String>();
    // Same error: Naming.bind("rmi://"+RMIUtils.getHost()+"/quicksortfactory", strQSFactory);

    Registry registry = LocateRegistry.getRegistry();
    registry.rebind("quicksortfactory-string", strQSFactory);
}

ISortFactory

public interface ISortFactory<T> extends Remote {
    public ISorter<T> createSorter() throws RemoteException;
}

实施 QuickSortFactory

public class QuickSortFactory<T> extends UnicastRemoteObject implements ISortFactory<T> {
    private static final long serialVersionUID = -4856366323843718656L;

    public QuickSortFactory() throws RemoteException {
        super();
    }

    @Override
    public ISorter<T> createSorter() throws RemoteException {
        return new QuickSort<T>();
    }
}

ISorter、QuickSorter 和引用对象 ISorter 扩展 Remote 及其方法抛出 RemoteExceptions。 QuickSort 扩展 SortLogic 并实现 ISorter。它的方法抛出RemoteExceptions。 SortLogic 扩展 UnicastRemoteObject。它的方法抛出RemoteExceptions。

由于我使用的是 JDK 1.5+，我不需要担心存根。 rmir​​egistry 运行良好，否则我会遇到不同的错误。

文字控制台输出

2013-11-20 00:57:00 DEBUG RMIUtils:33 - Policy file path changed to 'C:\Users\Mark\AppData\Local\Temp\rmi-sorter5248481413010560777.policy'
2013-11-20 00:57:00 DEBUG RMIUtils:38 - RMI hostname set to 127.0.0.1
2013-11-20 00:57:00 DEBUG RMIUtils:27 - Codebase path added: file:/F:/Development/Git/Personal/parallel-sorter/bin/
Exception in thread "main" java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: nl.marktielemans.rmisorter.server.factory.ISortFactory
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:400)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:248)
    at sun.rmi.transport.Transport$1.run(Transport.java:159)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:662)
    at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255)
    at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233)
    at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359)
    at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)
    at nl.marktielemans.rmisorter.server.SortServer.main(SortServer.java:42)
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: nl.marktielemans.rmisorter.server.factory.ISortFactory
    at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
    at sun.rmi.server.UnicastServerRef.oldDispatch(UnicastServerRef.java:390)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:248)
    at sun.rmi.transport.Transport$1.run(Transport.java:159)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:155)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:535)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:790)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:649)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.ClassNotFoundException: nl.marktielemans.rmisorter.server.factory.ISortFactory
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:249)
    at sun.rmi.server.LoaderHandler.loadProxyInterfaces(LoaderHandler.java:709)
    at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:653)
    at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:590)
    at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:628)
    at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:294)
    at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:242)
    at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1535)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1491)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1748)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1327)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:349)
    ... 12 more

无代码库参数

我尝试过不使用 codebase 参数，但不确定如何在 RMI 类路径中包含我应该阅读的类。

我已经尝试使用上面的RegistryLocator.getRegistry() 从SortServer 中的代码启动注册表，以及从在我的bin 目录中打开的命令行启动它。不过，我会得到同样的错误。

Answer 1

java.lang.ClassNotFoundException: nl.marktielemans.rmisorter.server.factory.ISortFactory
...
at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)

注册表的 CLASSPATH 中没有该类。

如果您使用java.rmi.server.codebase 属性，则需要在导出任何远程对象之前设置它，并且代码库需要是注册表和客户端可以使用的东西。

public static void addCodeBaseFor(Class<?> clazz) {
    System.setProperty("java.rmi.server.codebase", clazz.getProtectionDomain().getCodeSource().getLocation().toString());
}

这行不通。从客户端无法看到包含 JAR 文件在服务器上的位置。一般是 http: 或 ftp: URL。