Rserve Exception: Handshake failed - java

I am new to language R
and was trying a simple program in java using RConnection but it is giving this exception
org.rosuda.REngine.Rserve.RserveException: Handshake failed: expected 32 bytes header, got -1
at org.rosuda.REngine.Rserve.RConnection.<init>(RConnection.java:107)
at org.rosuda.REngine.Rserve.RConnection.<init>(RConnection.java:60)
at org.rosuda.REngine.Rserve.RConnection.<init>(RConnection.java:44)
at test.sandeep.main(sandeep.java:9)
thats in the contuctor of RConnection. Can anyone tell what might be wrong
package test;
import org.rosuda.REngine.Rserve.RConnection;
public class sandeep {
public static void main(String[] str) {
try {
System.out.println("hii");
RConnection c = new RConnection();
System.out.println("hii");
double d[] = c.eval("rnorm(10)").asDoubles();
for (double td : d) {
System.out.println(td);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}

The error says that read has failed immediately after connecting to Rserve. Your Java code is fine (assumint you are connecting to a local instance of Rserve). The issue is likely on the other side -- check that Rserve is running (see Rserve FAQ). You can also start Rserve in debug mode (Rserve(TRUE) in R) to see what happens on the server side.

If you are running RServe on a linux box, make sure that you have the configuration file in /etc/ location with name "Rserv.conf" and with contents
remote enable
This enables remote access to RServe

Related

not able to connect the GCP RabbitMQ from java code Getting Connection Exception [duplicate]

I have used RMI in my code :
import java.rmi.*;
public interface AddServerIntf extends Remote {
double add(double d1,double d2) throws RemoteException;
}
import java.rmi.*;
import java.rmi.server.*;
public class AddServerImpl extends UnicastRemoteObject implements AddServerIntf {
public AddServerImpl() throws RemoteException {
}
public double add(double d1,double d2) throws RemoteException {
return d1+d2;
}
}
import java.net.*;
import java.rmi.*;
public class AddServer {
public static void main(String args[]) {
try {
AddServerImpl addServerImpl=new AddServerImpl();
Naming.rebind("AddServer",addServerImpl);
} catch(Exception exc) {
System.out.println(exc);
}
}
}
import java.rmi.*;
public class AddClient {
public static void main(String args[]) {
try {
String Url="rmi://"+args[0]+"/AddServer";
AddServerIntf addServerIntf=(AddServerIntf)Naming.lookup(Url);
System.out.println("The first number is "+args[1]);
double d1=Double.valueOf(args[1]).doubleValue();
System.out.println("The second number is: "+args[2]);
double d2=Double.valueOf(args[2]).doubleValue();
System.out.println("The Sum is: "+addServerIntf.add(d1,d2));
} catch(Exception exc) {
System.out.println(exc);
}
}
}
These are 4 .java files written.
Next i compile all these files.Then I create a stub using rmic AddServerImpl. After that i start rmi registry on server side using start rmiregistry. Then i start server using java AddServer and finally client using java AddClient 27.60.200.80 5 9.
But nothing happens
Exception that is thrown on client side is java.net.ConnectException : connection timed out : connect
What is the reason and how can i solve this?
On client machine these are the following .class files AddClient.class AddServerImpl.class AddServerImpl_Stub.class and on server side AddServer.class AddServerImpl.class AddServerImpl_Stub.class AddServerIntf.class
The error message says it all: your connection timed out. This means your request did not get a response within some (default) timeframe. The reasons that no response was received is likely to be one of:
a) The IP/domain or port is incorrect
b) The IP/domain or port (i.e service) is down
c) The IP/domain is taking longer than your default timeout to respond
d) You have a firewall that is blocking requests or responses on whatever port you are using
e) You have a firewall that is blocking requests to that particular host
f) Your internet access is down
Note that firewalls and port or IP blocking may be in place by your ISP
Number (1): The IP was incorrect - is the correct answer. The /etc/hosts file (a.k.a.
C:\Windows\system32\drivers\etc\hosts ) had an incorrect entry for the local machine name.
Corrected the 'hosts' file and Camel runs very well. Thanks for the pointer.
Exception : java.net.ConnectException
This means your request didn't getting response from server in stipulated time. And their are some reasons for this exception:
Too many requests overloading the server
Request packet loss because of wrong network configuration or line overload
Sometimes firewall consume request packet before sever getting
Also depends on thread connection pool configuration and current status of connection pool
Response packet lost during transition
If you're pointing the config at a domain (eg fabrikam.com), do an NSLOOKUP to ensure all the responding IPs are valid, and can be connected to on port 389:
NSLOOKUP fabrikam.com
Test-NetConnection <IP returned from NSLOOKUP> -port 389

Connecting to Siebel using Java databeans hangs forever

Hi Below is a sample code I've written:
import com.siebel.data.*;
import com.siebel.data.SiebelException;
public class DataBeanDemo
{
private SiebelDataBean m_dataBean = null;
private SiebelBusObject m_busObject = null;
private SiebelBusComp m_busComp = null;
public static void main(String[] args)
{
DataBeanDemo demo = new DataBeanDemo();
}
public DataBeanDemo()
{
try
{
m_dataBean = new SiebelDataBean();
m_dataBean.login("Siebel://devServerXYZ:7777/XYZ/
ecommunication_enu", ROSADMIN, ROSADMIN, "enu");
System.out.println("Connected");
m_busObject = m_dataBean.getBusObject("Opportunity");
m_busComp = m_busObject.getBusComp("Opportunity");
m_dataBean.logoff();
}
catch (SiebelException e)
{
System.out.println(e.getErrorMessage());
}
}
}
This code executes without issues, but gets stuck at m_dataBean.login(). And never returns.
What could be the issue?
If I try to change connect string (even port name, from 7777 to any other number like 2320, 2321) then I get error could not open a session in 4 attempts SBL-JCA-00200.
3 things to verify
Parameters in the connect string. Gtway server name, OM comp name, port number etc. (Username/Password error is showed immediately but rest others throw generic errors or hung forever)
(This is something that's specific to Siebel) Ensure that Java subsystem profile has classpath pointing to siebel.jar and siebelJI_lang.jar files
Siebel Server is up and running.
If LDAP is true, then such logins cannot be used using Databeans.
In my case it was 1 & 2, that was causing issues. By the way Comp name is case sensitive.

java.net.ConnectException while running webservice?

I am developing the web service where in I want to connect to the SOA server. It's giving connection exception.
Code:
public class ConnectSOA{
public static void main(String[] args){
Map<IWorkflowServiceClientConstants.CONNECTION_PROPERTY, String> connProperties = new HashMap<IWorkflowServiceClientConstants.CONNECTION_PROPERTY, String>();
connProperties.put(IWorkflowServiceClientConstants.CONNECTION_PROPERTY.CLIENT_TYPE,WorkflowServiceClientFactory.REMOTE_CLIENT);
connProperties.put(IWorkflowServiceClientConstants.CONNECTION_PROPERTY.EJB_PROVIDER_URL,"t3://10.10.78.79:8001");
connProperties.put(IWorkflowServiceClientConstants.CONNECTION_PROPERTY.EJB_INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");
try {
workflowServiceClient = WorkflowServiceClientFactory
.getWorkflowServiceClient(connProperties, null, null);
itaskQueryService = workflowServiceClient.getTaskQueryService();
statePredicate = new Predicate(
TableConstants.WFTASK_STATE_COLUMN, Predicate.OP_EQ,
IWorkflowConstants.TASK_STATE_ASSIGNED);
iworkFlowContext = itaskQueryService.authenticate("demouser","demo1".toCharArray(), null);
} catch(Exception e ){
e.printStackTrace();
}
}
}
Exception :
java.net.ConnectException: t3://10.10.78.79:8001 Bootstrap to: hostname/'10.10.78.79:8001' over: 't3' got an error or timed out
I have check the soa server its up and running on the machine.
Can you ping your weblogic?
java weblogic.Admin -url t3://IP:8001 -username xxx -password xxx PING 10
I see that you have 10.10.78.79:8001 and in Exception IP:8001
Could be that your server is not ok. Check the config. See your config.xml and what the listen address for the server is and verify that you can ping it.

Exception in thread "main" java.net.BindException: Address already in use - Error in Netbeans only

On my machine, the following code compiles within Eclipse but throws an exception within Netbeans. The error message says "Exception in thread "main" java.net.BindException: Address already in use".
What is the proper configuration within Netbeans to make this code compile? It seems like the problem has to do with the fact that I have two main functions. If I start running either one of the apps, the second will fail to start, throwing the exception posted above.
Server.java
import java.io.*;
import java.net.*;
public class Server {
public static void main(String[] args) throws Exception {
Server myServ = new Server();
myServ.run();
}
public void run() throws Exception {
ServerSocket mySS = new ServerSocket(9999);
Socket SS_accept = mySS.accept();
InputStreamReader mySR = new InputStreamReader(SS_accept.getInputStream());
BufferedReader myBR = new BufferedReader(mySR);
String temp = myBR.readLine();
System.out.println(temp);
}
}
Client.java
import java.io.*;
import java.net.*;
public class Client {
public static void main(String[] args) throws Exception {
Client myCli = new Client();
myCli.run();
}
public void run() throws Exception {
Socket mySkt = new Socket("localhost", 9999);
PrintStream myPS = new PrintStream(mySkt.getOutputStream());
myPS.println("Hello server");
}
}
The problem is due to the fact that you left one instance of your server running and then started another one.
The way to achieve what I want is to right-click on the particular class (ex. Server.java) that I want to run and select "Run this file". This enables me to run only the Server app. Then, do the same process for the other file, Client.java.
However, Netbeans is somewhat confusing/deceiving in this particular circumstance. What Netbeans does is it runs the Server process, but labels that process as the name of the project (ex. MyTestNetworkingProject) and puts a run number on it, thus giving us MyTestNetworkingProject run #1 (it actually leaves out the #1 on the first process). Then, if I go to the Client.java file and select "Run this file", it generates a second process, MyTestNetworkingProject run #2. It then generates a second results window down at the bottom of the screen, as it generates these in new tabs as new processes get created.
Because of the nature of my specific code, what I wanted to see in my results window to confirm that my application was working was I wanted to observe the Server.java results window (which in this case is MyTestNetworkingProject run #1). Given my exact sequence of steps outlined above of running the different files, run #2 is the last run process and thus the tab on top, covering the run #1 tab. I can click on run #1 and see the results I was hoping to see in the console ("Hello server"), but I just have to know/remember that MyTestNetworkingProject run #1 represents the Server app and not the Client app.
Uncool, IMO.
If you write this in Windows OS,you can use "netstat -nao" to see which process use the 9999 port.If it is some unimportant process,you can kill this process.Otherwise you can change the port of the pragram.
I change the port address and it work for me in the Neat Beans IDE . This problem will come if we used the same port address for other one times . so to fix this error you have to change the port address and I am sure it will work
Server.java
public class SocServer {
public static void main(String[] args) {
try {
ServerSocket server = new ServerSocket(5001);
Socket client = server.accept();
DataOutputStream os = new DataOutputStream(client.getOutputStream());
os.writeBytes("Hello Sockets\n");
client.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Client.java
public class SocClient {
public static void main(String[] args) {
try {
Socket socClient = new Socket("localhost", 5001);
InputStream is = socClient.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String receivedData = br.readLine();
System.out.println("Received Data: " + receivedData);
} catch (IOException e) {
e.printStackTrace();
}
}
}
refer above code and it works for me..
I did try the method catch and solved the problem.

RMI connection refused

I am trying to get a rmi connection going. I have ran into many security issues but have been unable to find a way past all this. I execute my jar file with:
java -Djava.security.policy=java.security.AllPermission -jar "myjarfile"
The code I have been using to create this is:
public class server
{
public static void main(String args[])throws Exception
{
if (System.getSecurityManager() == null)
System.setSecurityManager ( new RMISecurityManager() {
public void checkConnect (String host, int port) {}
public void checkConnect (String host, int port, Object context) {}
});
try
{
sampleserverimpl server = new sampleserverimpl();
System.out.println("SERVER IS WAITING");
LocateRegistry.createRegistry(2020);
//Runtime.getRuntime().exec("rmiregistry 2020");
Naming.rebind("//localhost:2020/SERVER", server);
}
catch(Exception e)
{
System.out.println(e);
}
}
};
The error trace I am receiving is:
Exception in thread "RMI TCP Connection(idle)" java.security.AccessControlExcept
ion: access denied (java.net.SocketPermission 127.0.0.1:31199 accept,resolve)jav
a.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
java.io.EOFException
I have tried different ways to get around this, can anyone see the issue here?
Thanks
-Djava.security.policy accepts a URL which points to a policy file which in turn contains the permissions. So you should have: -Djava.security.policy=/some/path/my.policy as the JVM argument where the my.policy file contains:
grant {
permission java.security.AllPermission;
};
Also, in order to avoid the NULL check present in your code and the manual creation of a SecurityManager, you can request a SecurityManager be automatically installed for your application by passing the JVM switch: -Djava.security.manager.
Your final JVM invocation should look like:
java -Djava.security.manager -Djava.security.policy=/some/path/my.policy
This is two separate exceptions. The first is a permission problem. The second one, the EOFException, could have any of a number of causes. I would need to see java -version and the complete stack trace to assist further.

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