Implementando webservices em dispositivos J2ME

Implementando webservices em dispositivos J2ME

JSR 172, Web Services API, extend a plataforma J2ME para suportar web services. Esta webservice api consiste em 2 pacotes opcionais: “Java API for Remote Method Invocations” e “Java API for XML Processing”.

Abaixo está uma ilustração simples do webservice usando parsers diferentes do xml.

import java.io.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

import org.ksoap.*;
import org.kobjects.serialization.*;
import org.kxml.*;
import org.kxml.io.*;
import org.kxml.parser.*;

public class HelloWorld extends MIDlet implements CommandListener {

private Display display;
private Command doneCommand;
private TextField textField;

public HelloWorld() throws Exception {
display = Display.getDisplay(this);
doneCommand = new Command("DONE", Command.CANCEL, 1);
}

private String soapMesg =
"<SOAP-ENV:Envelope " +
"xmlns:SOAP-ENV=\"http://www.w3.org/2001/12/soap-envelope\" " +
"xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " +
"xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">" +
"<SOAP-ENV:Body>" +
"<message xsi:type=\"xsd:string\">Hello World</message>" +
"<message02 xsi:type=\"xsd:string\">unreachable</message02>" +
"</SOAP-ENV:Body>" +
"</SOAP-ENV:Envelope>";

private String soapRespMesg =
"<SOAP-ENV:Envelope " +
"xmlns:SOAP-ENV=\"http://www.w3.org/2001/12/soap-envelope\" " +
"xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " +
"xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">" +
"<SOAP-ENV:Body>" +
"<result>" +
"<message xsi:type=\"xsd:string\">Hello World</message>" +
"</result>" +
"</SOAP-ENV:Body>" +
"</SOAP-ENV:Envelope>";

private String processMesg(String mesg) throws Exception {
ByteArrayInputStream bis = new ByteArrayInputStream(mesg.getBytes());
InputStreamReader reader = new InputStreamReader(bis);
XmlParser xp = new XmlParser(reader);

SoapEnvelope envelope = new SoapEnvelope(new ClassMap(Soap.VER12));
envelope.parse(xp);

return (String) envelope.getBody();
}

private String processRespMesg(String mesg) throws Exception {
ByteArrayInputStream bis = new ByteArrayInputStream(mesg.getBytes());
InputStreamReader reader = new InputStreamReader(bis);
XmlParser xp = new XmlParser(reader);

SoapEnvelope envelope = new SoapEnvelope(new ClassMap(Soap.VER12));
envelope.parse(xp);

return (String) envelope.getResult();
}

public void startApp() {
String mesg;
Form form = new Form("Exemplo Hello World");
try {
mesg = processMesg(soapMesg);
} catch (Exception e) {
mesg = "falha no parsing";
e.printStackTrace();
}
form.append(new StringItem("SoapMesg", mesg));
try {
mesg = processRespMesg(soapRespMesg);
} catch (Exception e) {
mesg = "falha no parsing";
e.printStackTrace();
}
form.append(new StringItem("SoapRespMesg", mesg));

form.addCommand(doneCommand);
form.setCommandListener((CommandListener) this);
display.setCurrent(form);
}

public void pauseApp() {
}

public void destroyApp(boolean unconditional) {
}

public void commandAction(Command command, Displayable screen) {
if (command == doneCommand) {
destroyApp(false);
notifyDestroyed();
}
}
}