RE: Accessing Web Services from the web

[Wimmer, Matthias]

Eric:

I think this is an issue of Servlets and JSPs. Once you are a little bit
familiar with this, I think you can easily retrieve one parameter (named
machine_name or so) out of an HTML form. Then you just call LoadClient.main(
machine_name) and get the result.

I am not very familiar with Servlets and JSPs but this is the way I would
approach.

best regards
Matthias Wimmer



-----Original Message-----
From: Eric Roberts [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 4:43 PM
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]; Jeson Martajaya
Subject: Accessing Web Services from the web


Ok, I have a web service class that i want to use to access loads on 
certain machines.  It takes one parameter, the machine name.  The Java 
source looks like this:

(begin source here)
package samples.userguide.load;

import org.apache.axis.client.Call;
import org.apache.axis.client.Service;
import org.apache.axis.encoding.XMLType;
import org.apache.axis.utils.Options;

import javax.xml.rpc.ParameterMode;

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

                Options options = new Options(args);

                String endpoint = "http://localhost:"; + options.getPort()
+"/axis/Load.jws";

                args = options.getRemainingArgs();

                if (args == null || args.length != 1) {
                        System.err.println("Usage: LoadClient arg1");
                        return;
                }

                String s1 = new String(args[0]);

                Service service = new Service();
                Call    call    = (Call) service.createCall();

                call.setTargetEndpointAddress(new java.net.URL(endpoint) );
                call.setOperationName("getBatchQueueLoad");
                call.addParameter( "machine", XMLType.XSD_STRING,
ParameterMode.IN);
                call.setReturnType(XMLType.XSD_STRING);

                String ret = "";
                try {
                ret = (String) call.invoke(new Object[] {s1});
                }
                catch(Exception e) {
                        System.out.println("s1 = "+s1+"  ret = '"+ret+"'");
                        System.out.println("ret BAAAAADDDD!!\n" + e);
                        e.printStackTrace();
                }
                System.out.println(ret);
        }

}


The location of this file is 
/usr/local/apps/xml-axis-beta2/samples/userguide/load



The Load.jws file looks like this

(begin code here)

import java.net.URL;
import java.net.MalformedURLException;
import java.io.*;

public class Load {
  public static String getBatchQueueLoad (String machine)
  {
    String line ="";
    try {
      URL u = new URL ("http://www.tacc.utexas.edu/~rich/hipcat_data/"; + 
machine + "_load.txt");
      BufferedReader data = new BufferedReader
                ( new InputStreamReader( u.openStream() ));
      line = data.readLine();
      data.close();
     }
     catch (IOException e) {
      System.err.println("Error: " + e);
     }

    return line;
  }

}

The location of the Load.jws file is her
/usr/local/apps/jakarta-tomcat-4.0.4-b1/webapps/axis

Everything works great when I run the command

java samples.userguide.load.LoadClient machine_name

I get back the load on the machine.


I want to have a web interface with forms fields where I can put in the 
machine name and click submit and have the load returned and displayed in 
and HTML page.

Does this call for servlets/jsp?  I keep reading about WSDL everywhere but 
noone seems to explain how to utilize it.  Every tutorial seems to stop 
short of telling how to access a web service from the WEB.  What am I 
missing?  Am I going in the right direction? 

Many thanks in advance

-- 
_____________________________________________________________________
Eric Roberts                                 [EMAIL PROTECTED]
Grid Computing Group                             
Texas Advanced Computing Center                 
University of Texas at Austin    http://www.tacc.utexas.edu/~ericrobe
_____________________________________________________________________