CODEWITHSUNDEEP
javaxml-rpc
Chris Bennett
Chris Bennett

Reputation: 181

can't cast to integer

I am writing a java program where I want to simulate a client-server relationship with remote procedure calls using xmlrpc.

However when I try to remotely call the method I get this error message:

'JavaClient: XML-RPC Consumer Fault #java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer'

This is the method on the client side that is producing the error:

public String getHashsize() {

      // Execute the remote call, using the handler
         try
     {
         argHashsize = new Vector(); //see next method for comments
         argHashsize.addElement(serverURL);

         // make the call
         String callit = ("GetSize.sendHashSize");
         sizeHash =  (Integer)client.execute(callit, argHashsize );
     }
         // Use XmlRpcException errors
         catch (XmlRpcException exception) {
             System.err.println("JavaClient: XML-RPC Consumer Fault #" +
                                Integer.toString(exception.code) + ": " +
                                exception.getCause() + "" + exception.toString());
         } catch (Exception exception) {
             System.err.println("JavaClient: XML-RPC Consumer Fault #" + exception.toString());
         }
      String StrsizeHash = Integer.toString(sizeHash); // Cast sizeHash to String
     return StrsizeHash;
     }

This is the method that I am attempting to call:

public String sendHashSize(String getCaller) {
        // send back info to Message Broker
        sendbackserverdata = "number of staff: " + theHashtable.noStaff()
                + "  Caller: " + getCaller
                + "  Port: " + getServerPort()
                + "  " + getSendtime();
        //Store server info in Hashtable persist - could be a database
    /*persist.put("" + theHashtable.noStaff(),"" + sendbackserverdata);
         sendServerData = sendbackserverdata;
         stats.StoreinStatsHashtable("" + theHashtable.noStaff(), sendbackserverdata);*/
        return sendbackserverdata; // return to Consumer
    }

Upvotes: 0

Views: 1280

Answers (3)

Chris Bennett
Chris Bennett

Reputation: 181

The sendHashSize() method should have the following code instead:

public int sendHashSize(String getCaller)
   {
    // return to Consumer
    return theHashtable.noStaff();
   }

Upvotes: 0

Nir Alfasi
Nir Alfasi

Reputation: 53535

Instead of:

sizeHash =  (Integer)client.execute(callit, argHashsize );

try:

sizeHash =  Integer.valueOf(client.execute(callit, argHashsize ));

Of course that you have to make sure that a real integer is sent otherwise you'll get an exception for trying to convert a non-integer string to an integer (NumberFormatException).

Preferred approach:

The method sendHashSize() should return an int/Integer - and then you don't have to cast to Integer or use Integer.valueOf()

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1502396

Your sendHashSize method returns a String. It's not even the string representation of an integer - it's a string starting with "number of staff:".

I'm not surprised that it failed with an exception - it's just surprising that you expected it to work. Which integer would you have expected as a result?

Either change sendHashSize to return an int/Integer (perhaps theHashtable.noStaff()?), or avoid trying to cast it to an Integer on the calling side.

Additionally, this code is misleading:

catch (Exception exception) {
    System.err.println("JavaClient: XML-RPC Consumer Fault #" + exception.toString());
}

It's not an "XML-RPC Consumer Fault" - you've already caught those in the previous line. You've got an exception because you're trying to cast a String to an Integer... which is nothing to do with the XML-RPC layer.

Upvotes: 5

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