10 Nov 2017
Java RMI Test
RMI is a light way of remote communicate, different from HTTP restful api, RMI require using JAVA in both side. We have a production using RMI, recently need add a test for it.
The easiest way is using the lookup
public class TestRMIConnection {
private static final String RMI_SERVER_URL = "rmi://10.10.10.10:1099/RMI_SERVICE";
public static void main(String args[]) throws Exception {
if (System.getSecurityManager() == null) {
System.setSecurityManager(new RMISecurityManager());
}
try {
System.out.println("Connecting to " + RMI_SERVER_URL);
long beginTime = System.currentTimeMillis();
CalculationService service = (CalculationService) Naming.lookup(RMI_SERVER_URL);
long endTime = System.currentTimeMillis();
System.out.println("end printing response");
}
catch (Exception e) {
logger.error("Exception occured: " + e + " - " + RMI_SERVER_URL);
logger.error(e);
e.printStackTrace();
}
System.out.println("The test complete");
}
}
I was blocked by the error
java.security.AccessControlException: access denied ("java.net.SocketPermission" "10.10.10.10:1099" "connect,resolve")
After search, this issue may because of the RMI policy setting, to get more useful information, first need to add debug config. I use eclispe, add below arguments into -> run configuration -> (x)=Arguments -> VM arguments:
-Djava.security.debug=access,failure
-Djava.security.policy=client.policy
now we are able to print more information:
access: access denied ("java.net.SocketPermission" "10.10.10.10:1099" "connect,resolve")
java.lang.Exception: Stack trace
at java.lang.Thread.dumpStack(Thread.java:1365)
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:362)
at java.security.AccessController.checkPermission(AccessController.java:559)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
at java.lang.SecurityManager.checkConnect(SecurityManager.java:1051)
at java.net.Socket.connect(Socket.java:574)
at java.net.Socket.connect(Socket.java:528)
at java.net.Socket.<init>(Socket.java:425)
at java.net.Socket.<init>(Socket.java:208)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:40)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:147)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202)
at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:341)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Naming.java:101)
at traff.TestRMIConnection.main(TestRMIConnection.java:34)
access: access allowed ("java.security.SecurityPermission" "getPolicy")
checked the client.policy and server.policy, they accept all the permission.
grant { permission java.security.AllPermission; };
Still wrong, after lots of test, it is because the “client.policy” file location is not right. because I using windows, change the path to absolute path:
-Djava.security.debug=access,failure
-Djava.security.policy=C:\git\rmi\conf\client.policy
Finally, issue solved, now we can test the RMI heart beat test.
Reference
Til next time,
at 00:00
