java - rmi java.lang.ClassNotFoundException : testrmi2. fileserverimpl_Stub

Question

我正在编写一个简单的 rmi 应用程序，但遇到了问题。

如果我在同一目录中运行注册表，它就可以工作；但如果我更改运行注册表的目录，则不会。

注册表通常可以在另一台主机上工作，但只有目录的更改才能停止其功能。

我花了 3 天的时间来解决这个问题，但没有解决方案，我还更改了代码库参数的每个可能的配置，但什么也没改变。

我用目录描述一下情况和代码:

文件服务器.java:

`package testrmi2;
import java.rmi.*;

public interface fileserver extends Remote  {
 public void scrivifile(String nomefile, String arg) throws  RemoteException;
}

` fileserverimpl.java:

    package testrmi2;

import java.io.*;
import java.rmi.*;
import java.rmi.server.*;

public class fileserverimpl extends UnicastRemoteObject implements fileserver{
  public fileserverimpl() throws RemoteException {
    super();
  }
  public void scrivifile(String nomefile, String arg) throws RemoteException {
    try {
      FileWriter myfile = new FileWriter(nomefile);
      myfile.write(arg);
      myfile.close(); }
    catch (Exception e) {System.out.println(e);}
  }
  public static void main (String arg[]) {
    try {
       fileserverimpl s = new fileserverimpl();
        if (System.getSecurityManager() == null) {
            System.setSecurityManager(new RMISecurityManager());
        }
        String codebase = System.getProperty("classpath");
        System.out.println("Trying to access code base: " + codebase+"\n\nuse is "+System.getProperty("useCodebaseOnly"));
       Naming.rebind("//127.0.0.1:2005/fileserverimpl", s);
       System.out.println("Server attivato.");
} catch (Exception e) {System.out.println("errore inizializzazione server\n\n"+e.getMessage()+"\n\n\n");

}}}

客户端.java:

    package testrmi2;

import java.rmi.*;
import java.io.*;

public class client {
  public static void main (String arg[]) {
    fileserver myserver;
    String nomefile=" ";
    String testo=" ";
    System.out.println("Scrivi il nome del file");
    nomefile=ReadString();
    System.out.println("Scrivi il testo");
    testo=ReadString();
    try {
       myserver = (fileserver)   Naming.lookup("//127.0.0.1:2005/fileserverimpl");
        myserver.scrivifile(nomefile, testo);
      } catch (Exception e) {System.out.println(e);}
    }

   public static String ReadString() {
      BufferedReader stdIn =new BufferedReader(new InputStreamReader(System.in));
      String s=" ";
     try{
       s=stdIn.readLine();
      }
       catch(IOException e) {System.out.println(e.getMessage()); }
    return s;
   }
}

策略文件是:

grant {
        // Allow everything for now
        permission java.security.AllPermission;
}; 

所有这些文件都在目录中:

/Users/franco/Desktop/prova

为了编译它，我进入/Users/franco/Desktop/prova 目录并在终端中执行:

javac -cp . -d . *.java
rmic rmic testrmi2.fileserverimpl
jar cvf testrmi2.jar testrmi2/fileserver.class testrmi2/fileserverimpl_Stub.class

在另一个终端中使用以下命令但在另一个目录中运行注册表后:

export classpath=""
rmiregistry 2005 &

最后，我将在/Users/franco/Desktop/prova 目录中运行 filesereveimpl.class 与终端一起运行并写入:

java -classpath /Users/franco/Desktop/prova/ -Djava.rmi.server.codebase=file:/Users/franco/Desktop/prova/testrmi2.jar  -Djava.security.policy=testrmi2/policy testrmi2.fileserverimpl &

但结果是:

    Trying to access code base: null

use is null
errore inizializzazione server

RemoteException occurred in server thread; nested exception is: 
    java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
    java.lang.ClassNotFoundException: testrmi2.fileserverimpl_Stub

我还尝试在本地网络服务器 xampp 上公开他的 jar 并尝试使用以下命令运行:

java -classpath .  -Djava.rmi.server.codebase=http://127.0.0.1/testrmi2/  -Djava.security.policy=testrmi2/policy  testrmi2.fileserverimpl &

或者用:

java -classpath .  -Djava.rmi.server.codebase=http://127.0.0.1/testrmi2.jar  -Djava.security.policy=testrmi2/policy  testrmi2.fileserverimpl &

但我得到了相同的结果。

Answer 1

尝试在执行 rmregistry 之前设置类路径 var:

export classpath="/Users/franco/Desktop/prova/"
rmiregistry 2005 &