java - RMI 服务器 java.security.AccessControlException : access denied

Question

我正在构建一个 RMI 应用程序并且我有以下服务器类。但是，当我在 eclipse 中运行它时，出现以下异常。出了什么问题，我该如何解决？我花了最后 2 天时间在网上阅读类似的问题，但找不到解决方案。我怀疑它与策略文件有关，但我不知道如何使用它。另外，如果问题出在我运行它的方式上，请给我在 eclipse 中执行此操作的指导。

import java.rmi.RemoteException;
import java.rmi.RMISecurityManager;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import javax.rmi.ssl.SslRMIClientSocketFactory;
import javax.rmi.ssl.SslRMIServerSocketFactory;


public class MyServer extends UnicastRemoteObject implements Interface {

    private static final int PORT = 2019;

    public MyServer() throws Exception {
        super(PORT, new SslRMIClientSocketFactory(), new SslRMIServerSocketFactory());
    }

    public static void main(String args[]) {


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

        try {

            Registry registry = LocateRegistry.createRegistry(PORT, new SslRMIClientSocketFactory(), new SslRMIServerSocketFactory());

            MyServer obj = new MyServer();


            registry.bind("HelloServer", obj);

        } catch (Exception e) {
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
    }

    @Override
    public void sayHello() throws RemoteException {
        System.out.println("Hello");
    }
}

--

access denied ("java.net.SocketPermission" "localhost:2019" "listen,resolve")
java.security.AccessControlException: access denied ("java.net.SocketPermission" "localhost:2019" "listen,resolve")
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkListen(Unknown Source)
    at java.net.ServerSocket.bind(Unknown Source)
    at java.net.ServerSocket.<init>(Unknown Source)
    at java.net.ServerSocket.<init>(Unknown Source)
    at javax.rmi.ssl.SslRMIServerSocketFactory$1.<init>(Unknown Source)
    at javax.rmi.ssl.SslRMIServerSocketFactory.createServerSocket(Unknown Source)
    at sun.rmi.transport.tcp.TCPEndpoint.newServerSocket(Unknown Source)
    at sun.rmi.transport.tcp.TCPTransport.listen(Unknown Source)
    at sun.rmi.transport.tcp.TCPTransport.exportObject(Unknown Source)
    at sun.rmi.transport.tcp.TCPEndpoint.exportObject(Unknown Source)
    at sun.rmi.transport.LiveRef.exportObject(Unknown Source)
    at sun.rmi.server.UnicastServerRef.exportObject(Unknown Source)
    at sun.rmi.registry.RegistryImpl.setup(Unknown Source)
    at sun.rmi.registry.RegistryImpl.<init>(Unknown Source)
    at sun.rmi.registry.RegistryImpl.<init>(Unknown Source)
    at java.rmi.registry.LocateRegistry.createRegistry(Unknown Source)
    at MyServer.main(MyServer.java:27)

Answer 1

非常简单。

access denied ("java.net.SocketPermission" "localhost:2019" "listen,resolve")

意味着策略文件必须授予权限

java.net.SocketPermission "localhost:2019", "listen,resolve"

或任何正确的语法。使用 policytool 使其正确。您可能希望通配端口号。并且您必须通过 java.security.policy 系统属性指定策略文件的位置。当你得到其他访问控制异常时，就像你在测试中一样，你必须同样添加相应的权限，直到关闭。

但我更愿意问您为什么要使用安全管理器。除非您要使用代码库功能，否则没有必要，这很少见，并且在服务器中也没有必要，除非您要使用代码库功能从客户端上传类，这是很多更稀有。