java - 客户端线程在联系 RMI 服务器时失败 : java. rmi.UnmarshalException:错误解码返回

Question

这个问题已经有答案了:

java.rmi.ServerException: RemoteException occurred in server thread (ClassNotFoundException) (5 个回答)

已关闭 5 年前。

我有一个客户端，它从 JSP 页面获取输入，然后将其提供给一个线程，该线程被添加到线程池中，当它执行时，该线程会联系 RMI 服务器以获取远程对象，然后应该返回结果将显示在新的 JSP 页面上，问题是一旦执行可运行代码，我会收到以下错误:

java.rmi.UnmarshalException: error unmarshalling return; nested exception is: 
    java.lang.ClassNotFoundException: servertest.DictionaryInterface (no security manager: RMI class loader disabled)
    at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
    at java.rmi.Naming.lookup(Unknown Source)
    at Client.LookupWorker.run(LookupWorker.java:27)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: servertest.DictionaryInterface (no security manager: RMI class loader disabled)
    at sun.rmi.server.LoaderHandler.loadProxyClass(Unknown Source)Thread didnt finish its job properly, error: java.lang.NullPointerException

这是 JSP 页面背后的 Java 代码

if (request.getParameter("word") != null) {
            String word = request.getParameter("word");
            String res;
            System.out.println("The word to find: "+word);

            // Get handle on our pool
            WorkerPool pool = WorkerPool.getInstance( );
            // Create Job
            LookupWorker wordWork = new LookupWorker(word);
            // Add job to pool
            res = pool.addJob(wordWork);
            request.getSession().setAttribute("result", res);
            response.sendRedirect("/SearchResults"); 
        }

这是线程类:

package Client;

import java.net.MalformedURLException;
import java.rmi.Naming;
import java.rmi.NotBoundException;
import java.rmi.RemoteException;

import DictionaryInterface.DictionaryInterface;

public class LookupWorker implements WorkerPlan {

    private String word;
    private String jobName;
    private String serverResult;
    private long threadId;

    public LookupWorker(String w) {
        super();
        this.word = w;
        jobName = "Lookup Job";
    }

    @Override
    public void run(){
        DictionaryInterface Dictonary = null;
        try {
            Dictonary = (DictionaryInterface) Naming.lookup("rmi://127.0.0.1:1099/DictionaryService");
        } catch (MalformedURLException | RemoteException | NotBoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        try {
            serverResult = Dictonary.lookup(word);
        } catch (RemoteException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
            System.out.println(serverResult); 
            threadId = Thread.currentThread().getId();
    }

    public String getServerResult() {
        return serverResult;
    }

    public String getWord() {
        return word;
    }

    public String getJobName() {
        return jobName;
    }

    @Override
    public String toString() {
        return jobName + " [Id= " + threadId + "word= " + word + ", serverResult= " + serverResult + "]";
    }   

}

执行线程涉及的池代码:

public String addJob(WorkerPlan job) {
        String result;
        threadCounter++;
        // Adding new lookup job to our queue
        System.out.println("Adding a " + job.getJobName() + " to the queue. Searching for: " + job.getWord() + " Job number: " + threadCounter);
        executor.execute(job);
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } // sleep so we can wait for rmi object to come in
        System.out.println(job.toString());
        result = job.getServerResult();
        return result;
    }

我已经尝试了不同的虚拟机参数路径，但无法使其工作，非常感谢任何帮助。

Answer 1

Client thread fails when contacting RMI server:

没有。查找 RMI 注册表时失败。查看堆栈跟踪。

java.rmi.UnmarshalException: error unmarshalling return

查看堆栈跟踪。根本错误是

java.lang.ClassNotFoundException: servertest.DictionaryInterface (no security manager: RMI class loader disabled)

您尚未将此类部署到客户端。您似乎同时拥有 servertest.DictionaryInterface 和 DictionaryInterface.DictionaryInterface。你不能那样做。两端的包名必须相同。