Re: IllegalArgumentException when invoking axis2-webservice with client

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.help,comp.lang.java.programmer
Date:
Sat, 16 Feb 2008 19:53:09 -0500
Message-ID:
<XpGdncHtL97oGCranZ2dnUVZ_qKgnZ2d@comcast.com>
Lew wrote:

MC wrote:

i [sic] just wrote a webservice using the axis2-framework .. the
service can


Please do not multi-post. It annoys those with the most power to help
you and makes the conversation hard to follow. It's also silly, given
that mostly the same people frequent both groups.

be found here:
---------------------------------------------------
package de.testService;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Vector;

public class TestService {

    public Connection con = null;


Public instance variables are a Bad Idea. Instantiating class and
instance variables happens automatically; no need to say so explicitly.

    TransportContainer tc = new TransportContainer();


Unless other classes in the package need unmediated access to these
variables, make them private and use accessor and mutators to reach them
from other classes.

    Vector v = new Vector();


Vector is obsolete, since 1998, in fact. Use a real List implementation.

    public final void connection() throws Exception {
        Class.forName("com.mysql.jdbc.Driver");


You only need to load a class once per program run, not every time you
use it.

        con = DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/travelagent", "root", "");


Naturally, in production you'd use a non-root DB user.

    }

    public TransportContainer getHotels(String table) {
        try {
            connection();
            String sql = "SELECT * FROM " + table;
            PreparedStatement pStmt = con.prepareStatement(sql);


Don't concatenate values into SQL strings; it's a security risk. Use
PreparedStatement setString(), etc.

            ResultSet rs = pStmt.executeQuery();
            while (rs.next()) {
                v.addElement(new Hotel(rs.getString(2),
rs.getString(3), rs
                        .getString(4), rs.getString(6), rs.getInt(5)));
            }
        } catch (Exception e) {
            e.printStackTrace();


It's dangerous to continue after an exception. Logging is better than
stderr output.

        }
        tc.setData(v);
        return tc;

    }

}
---------------------------------------------------

the service uses a class called TransportContainer, which contains the
data that should be send from the service to the client. this class
can be found here:

---------------------------------------------------
package de.testService;

import java.util.Vector;

public class TransportContainer {

    public TransportContainer() {

    }

    public Vector v;

    public void setData(Vector data) {
        this.v = data;
    }

    public Vector getData() {
        return this.v;
    }
}
---------------------------------------------------

to invoke the service, i wrote a client which can be found here:
http://pastebin.com/d70807df3

---------------------------------------------------
package de.wsTester;

import javax.xml.namespace.QName;

import org.apache.axis2.AxisFault;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.rpc.client.RPCServiceClient;

import de.testService.*;

public class TestClient {

    public static void main(String[] args) throws AxisFault {
               RPCServiceClient sender = new RPCServiceClient();
        Options options = sender.getOptions();

        EndpointReference targetERP = new EndpointReference(
                "http://localhost:8080/axis2/services/testService");
        options.setTo(targetERP);

        QName opGetHotels = new QName("http://testService.de",
"getHotels");

        String table = "hotels";
        Object[] opArgs = new Object[] { table };

        Class[] returnTypes = new Class[] { TransportContainer.class };
        Object[] response = sender.invokeBlocking(opGetHotels,
opArgs,returnTypes);
    }

}
---------------------------------------------------

when i start the client, i get the following exception:

---------------------------------------------------
Exception in thread "main" java.lang.IllegalArgumentException:
argument type mismatch
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at
org.apache.axis2.databinding.utils.BeanUtil.deserialize(BeanUtil.java:391)

    at
org.apache.axis2.databinding.utils.BeanUtil.processObject(BeanUtil.java:655)

    at
org.apache.axis2.databinding.utils.BeanUtil.ProcessElement(BeanUtil.java:603)

    at
org.apache.axis2.databinding.utils.BeanUtil.deserialize(BeanUtil.java:535)

    at
org.apache.axis2.rpc.client.RPCServiceClient.invokeBlocking(RPCServiceClient.java:103)

    at de.wsTester.TestClient.main(TestClient.java:29)


Which one is line 29?

---------------------------------------------------

thx to soapmonitor, i can see that the service return the expected
data-structure

---------------------------------------------------
<?xml version='1.0' encoding='utf-8'?>
<soapenv:Envelope
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
  <soapenv:Body>
    <ns:getHotelsResponse xmlns:ns="http://testService.de">
      <ns:return xmlns:ax21="http://testService.de/xsd"
type="de.testService.TransportContainer">
        <ax21:data type="de.testService.Hotel">
          <ax21:hotelCity>MXnchen</ax21:hotelCity>
          <ax21:hotelCode>AX001</ax21:hotelCode>
          <ax21:hotelName>Axis2 Grand Hotel</ax21:hotelName>
          <ax21:numOfStars>5</ax21:numOfStars>
        </ax21:data>
        <ax21:data type="de.testService.Hotel">
          <ax21:hotelCity>Hamburg</ax21:hotelCity>
          <ax21:hotelCode>AX010</ax21:hotelCode>
          <ax21:hotelName>Axis2 Plaza</ax21:hotelName>
          <ax21:numOfStars>4</ax21:numOfStars>
        </ax21:data>
        <ax21:data type="de.testService.Hotel">
          <ax21:hotelCity>Unterammergau</ax21:hotelCity>
          <ax21:hotelCode>AX050</ax21:hotelCode>
          <ax21:hotelName>AchsenhXtte</ax21:hotelName>
          <ax21:numOfStars>1</ax21:numOfStars>
        </ax21:data>
      </ns:return>
    </ns:getHotelsResponse>
  </soapenv:Body>
</soapenv:Envelope>
-------------------------------------------------

whats wrong with my code? i would be thankful for any advice or hints
on how to improve my code.


At a first guess, it looks like the hotel data isn't converting from the
XML into your Java class correctly. It's hard to say without seeing the
schemas and the class definitions.


I see what's missing - you probably have to tell the "TransportContainer"
class that it actually has Hotel data in it, instead of just a Vector<?>. I'm
not so familiar with Axis2, but according to the online docs it shouldn't
require such explicit use of reflection. INstead you use the Axis tools and
AAR files to define and deploy the service and its XML-to-Java mappings.
Something has to tell the system that the list of items returned comprises
Hotel types.

--
Lew

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