Question

我正在努力在java中创建一个简单的RMI服务器。我想通过网络，所以我不能使用本地主机的IP地址。我写了很多代码，但我不断收到一条错误消息：

  java.security.AccessControlException: access denied("java.util.PropertyPermission" "java.security.policy" "write")
    at java.security.AccessControlContext.checkPermission(Unknown Source)
        at java.security.AccessController.checkPermission(Unknown Source)
        at java.lang.SecurityManager.checkPermission(Unknown Source)
        at java.lang.System.setProperty(Unknown Source)
at test_Client.TestClient.main(TestClient.java:31)

我已经做了很多寻找，似乎无法找出我的代码有什么问题。我的服务器启动正常，并在我指定的IP和端口号上运行。如果有人能帮助我找出为什么我会收到这个错误的错误。谢谢。以下是我的客户的示例代码

package test_Client;
//this is the client, it has it's own package 

import java.rmi.NotBoundException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.util.Scanner;
//import all needed rmi files


import test_Interface.Constant;
import test_Interface.testRMIInterface;
//import my constant file so port number can be found.
//import my test interface from my example interface project, example server testing

public class TestClient {
//start my class


    public static void main(String[] args) throws RemoteException, NotBoundException{
        //throws exceptions so everything is not in try catch blocks...

         if (System.getSecurityManager() == null) {
                System.setSecurityManager(new SecurityManager());
            }



         System.setProperty("java.security.policy", "C:/Users/Robert/workspace/ExampleClient");



         Registry registryClient = LocateRegistry.getRegistry(Constant.SERVER_IP, Constant.PORT_NUM);
        //make my registry client and use port number from constants in example interface
        //get the registry on the servers ip address with the port. 

         testRMIInterface remote =  (testRMIInterface) registryClient.lookup(Constant.RMI_ID);
        //using testInterface interface under my example interface
       //look up the RMI ID and link it to the object created above 




         //this is the one method i have on the server.

         String sendThis = "";
         System.out.println("Please enter a word");
         Scanner keyboard = new Scanner(System.in);
         sendThis = keyboard.next();
         System.out.println(remote.returnTest(sendThis));
        //simple call to the server method returnTest 
        //takes in a string. and returns a different one 
    }
}

Answer 1

您需要在安装SecurityManager.

之前设置策略属性
否则SecurityManager会加载默认策略，该策略不授予您更改策略的权限。

Java RMI客户端服务器java.security.AccessControlException：访问被拒绝（“java.util.PropertyPermission”“java.security.policy”“write”）

1 个答案: