Java远程方法调用

Question

If i call this server method with the client from different location iam getting following error.If i run the client from same location where the server is there I am getting output.

Please give some soltuions to call my rmi server with rmi client from different location.

Error
Exception in thread "main" java.rmi.UnmarshalException: error unmarshalling return; nested exception is: 
    java.lang.ClassNotFoundException: com.transform.xsl.XslFoTransformer_Stub (no security manager: RMI class loader disabled)
    at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
    at java.rmi.Naming.lookup(Naming.java:101)
    at com.transform.xsl.RmiClient.main(RmiClient.java:15)
Caused by: java.lang.ClassNotFoundException: com.transform.xsl.XslFoTransformer_Stub (no security manager: RMI class loader disabled)
    at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:394)
    at sun.rmi.server.LoaderHandler.loadClass(LoaderHandler.java:184)
    at java.rmi.server.RMIClassLoader$2.loadClass(RMIClassLoader.java:637)
    at java.rmi.server.RMIClassLoader.loadClass(RMIClassLoader.java:264)
    at sun.rmi.server.MarshalInputStream.resolveClass(MarshalInputStream.java:222)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1610)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1515)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1769)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1348)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
    ... 3 more

Code ======

import java.io.File;
import java.rmi.Remote;
import java.rmi.RemoteException;

public interface XslFoTransformerInterface extends Remote {
    public byte[] doTransform(File stylesheet, File datafile) throws Throwable,RemoteException;

}

public class XslFoTransformer extends UnicastRemoteObject  implements XslFoTransformerInterface {

    protected XslFoTransformer() throws RemoteException {
        super();

    }

    public byte[] doTransform(File stylesheet, File datafile) throws Exception {

        String fileName = datafile.getName();
        int pos = fileName.lastIndexOf(".");
        if (pos > 0) {
            fileName = fileName.substring(0, pos);

        }
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        File file = new File(fileName + ".xsl-fo");
        try {
            // File stylesheet = new
            // File("C:\\Users\\Q811213\\Documents\\XSLT\\files\\ECGSearchResultsPDF_changed1.xsl");
            // File datafile = new
            // File("C:\\Users\\Q811213\\Documents\\XSLT\\files\\NEWDATA.xml");
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.parse(datafile);
            TransformerFactory tFactory = TransformerFactory.newInstance();
            StreamSource stylesource = new StreamSource(stylesheet);
            Transformer transformer = tFactory.newTransformer(stylesource);
            DOMSource source = new DOMSource(document);
            ByteArrayOutputStream bos=new ByteArrayOutputStream();
            StreamResult result=new StreamResult(bos);
            transformer.transform(source, result);
             byte [] array=bos.toByteArray();


        return array;
        } catch (Exception e) {
            throw e;
        }}}


--Rmi server class


public class RmiServer {
    public static void main(String args[]) throws Exception{  
        try{  


        XslFoTransformerInterface stub=new XslFoTransformer();  
        Naming.rebind("rmi://localhost:1099/Xsl-Fo_Transform",stub);  
        }catch(Exception e){
            throw e;

        }  
        }  

}


--Rmi client created in different location



public class RmiClient {
    public static void main(String args[]) throws Throwable {
        try {
            XslFoTransformerInterface stub = (XslFoTransformerInterface) Naming
                    .lookup("rmi://localhost:1099/Xsl-Fo_Transform");
            System.out.println("stub is ready" + stub);
            File f1 = new File(
                    "C:\\Users\\s811213\\osbwstest\\XSL-FO_Transformer\\files\\ECGSearchResultsPDF_changed1.xsl");
            File f2 = new File(`enter code here`
                    "C:\\Users\\s811213\\osbwstest\\XSL-FO_Transformer\\files\\NEWDATA.xml");
            try {
                byte[] f = stub.doTransform(f1, f2);
                }cartch(){}

}}

If i call this server method with the client from different location iam getting following error.If i run the client from same location where the server is there i am getting output. Please give some soltuions to call my rmi server with rmi client from different location.

Answer 1

您需要将异常中命名的存根类部署到客户端。

Answer 2

In RMI client

XslFoTransformerInterface stub = (XslFoTransformerInterface) Naming .lookup("rmi://localhost:1099/Xsl-Fo_Transform");

you need to change localhost to server ip

Answer 3

I'm not sure if you running your program in different locations (no the server machine) with the updated version of your code for ip which you hard coded for localhost.

If this is not the problem, you must be sure that you placed the XslFoTransformerInterface class in your client codes in the same package as it is in server codes .

Also in the future if you have some Serializable POJO classes as the arguments or the return types of you remote methods, same rule is applied for them. Always put them in the same package as they reside is the server codes.

Good Luck.