安全Java RMI不适用于多台服务器securit

Question

我在ubuntu服务器上使用RMI开发了一个java代码。当RMI客户机和服务器位于同一台机器上时，它运行良好。当我使用两台机器（一台作为服务器，另一台作为客户端——都是ubuntu）时，它会给我“RMI连接拒绝异常”。为了解决这个问题，我尝试使用以下代码覆盖java策略文件：

System.setSecurityManager(new RMISecurityManager());
System.setProperty("java.security.policy","file:///home/{local path}/client.policy");

我在服务器端也使用了类似的代码

客户端和服务器策略文件的内容如下：

grant codebase  {
    permission java.security.AllPermission;
};

现在，我在客户端“System.setProperty（..”上遇到了以下异常如上图所示

java.security.AccessControlException: access denied (java.util.PropertyPermission java.security.policy write)
    at java.security.AccessControlContext.checkPermission(AccessControlContext.java:374)
    at java.security.AccessController.checkPermission(AccessController.java:546)
    at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)
    at java.lang.System.setProperty(System.java:725)
    at ParaselectionServlet.doPost(ParaselectionServlet.java:106)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:185)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:151)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:269)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

我不是java或ubuntu方面的专家，但有人能帮我解决上述问题吗

-拉什米