Latihan J2ME Http Connection

Beberapa jenis aplikasi mobile memerlukan konektivitas HTTP dan HTTPS. Jika perangkat bergerak tidak memiliki  dukungan  TCP/IP  internal  maka  konektivitas  tersebut  disediakan  operator  melalui sebuah gateway.  Mekanisme  ini  dipakai  luas  pada  perangkat  mobile  yang  tersedia  dipasaran.menunjukkan aplikasi client‐server menggunakan HTTP.

import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class formNilaiMidlet extends MIDlet implements CommandListener, Runnable{
    private Command cmdExit, cmdHitung;
    private Form form;
    private Alert alert;
    private TextField tfNama, tfNim, tfNilai1, tfNilai2, tfNilai3;
    private static Display display;
    private int errorcode = 0;
    private String hasil;
    public formNilaiMidlet(){
        display = Display.getDisplay(this);
    }
    public void startApp() {
        form = new Form("Hitung Nilai Mahasiswa");
        tfNim = new TextField("NIM: ", null, 32, TextField.NUMERIC);
        tfNama = new TextField("Nama: ", null, 32, TextField.ANY);
        tfNilai1 = new TextField("Nilai 1", null, 32, TextField.NUMERIC);
        tfNilai2 = new TextField("Nilai 2", null, 32, TextField.NUMERIC);
        tfNilai3 = new TextField("Nilai 3", null, 32, TextField.NUMERIC);
        cmdExit = new Command("Exit", Command.EXIT, 1);
        cmdHitung = new Command("Hitung", Command.SCREEN, 1);
        form.append(tfNim);
        form.append(tfNama);
        form.append(tfNilai1);
        form.append(tfNilai2);
        form.append(tfNilai3);
        form.setCommandListener(this);
        form.addCommand(cmdHitung);
        form.addCommand(cmdExit);
        display.setCurrent(form);
    }  
    public void pauseApp() {
        display.setCurrent(null);
    }  
    public void destroyApp(boolean force) {}
    public void commandAction(Command c, Displayable d){
        if(c == cmdExit){
            destroyApp(true);
            notifyDestroyed();
        }else if(c == cmdHitung){
            new Thread(this).start();
        }
    }
   
    public void run(){
        try{
            getData();
        }catch(Exception e){}
    }
   
    public void getData() throws Exception{
        String url = "";
        url = "http://localhost:8080/formNilai/index.jsp";
       
       
        HttpConnection hc = null;
        InputStream is = null;
        OutputStream os = null;
        StringBuffer messagebuffer = new StringBuffer();
        String temp = "";
        try{
            hc = (HttpConnection) Connector.open(url);
            hc.setRequestMethod(HttpConnection.POST);
            hc.setRequestProperty("User-Agent", "Profile/MIDP-2.0 Configuration/CLDC-1.0");
            hc.setRequestProperty("Content-Language", "en-US");
            hc.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            os = hc.openOutputStream();
            os.write(("nil1="+tfNilai1.getString()+"&nil2="+tfNilai2.getString()+"&nil3="+tfNilai3.getString()).getBytes());
            os.close();

            int rc = hc.getResponseCode();
            if(rc != HttpConnection.HTTP_OK)
                throw new IOException("HTTP response code : " + rc);
            is =  hc.openInputStream();
            int ch;
            long len = hc.getLength();

            if((len!=-1)){
                for(int i = 0;i<len;i++)
                    if((ch = is.read()) != -1){
                        messagebuffer.append((char)ch);
                        temp = temp + (char) ch;
                    }else{
                        while((ch = is.read()) != -1)
                            messagebuffer.append((char)ch);
                            temp = temp + (char) ch;
                    }
            }

            is.close();
       
            //Parsing prs = new Parsing();
            //prs.process(temp);
            //String message = "Kode :  " + prs.getCode() + "\nPesan :\n" + prs.getMsg();

            //textbox.setString("Nama : Dian\nPassword : 9999");
            //siHasil.setText(temp);
            hasil = "NIM: "+ tfNim.getString() +"\nNama: "+ tfNama.getString() +"\nNilai Akhir: "+ temp;
            alert = new Alert("Hasil");
            alert.setTimeout(Alert.FOREVER);
            alert.setString(hasil);
            display.setCurrent(alert);
       
        }catch (InterruptedIOException ei){
            errorcode = -1;
            throw ei;
        }catch (IOException ioe){
            errorcode = -2;
            throw ioe;
        }catch (Exception ie){
            errorcode = -3;
            throw ie;
        }finally{
            try{
                if(hc != null) hc.close();
            }catch (IOException ignored){}
            try{
                if(is != null) is.close();
            }catch (IOException ignored){}
            try{
                if(os != null) os.close();
            }catch (IOException ignored){}
        }
    }
}

Dan membuat satu file Http connection yang untuk menghubungkan antara keduanya.
untuk penghitungan nya di file jsp
contoh disini saya punya file: "http://localhost:8080/formNilai/index.jsp"

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%
    String nilai1, nilai2, nilai3;
    int nil1, nil2, nil3;
    double total;
   
    nilai1 = request.getParameter("nil1");
    nilai2 = request.getParameter("nil2");
    nilai3 = request.getParameter("nil3");
   
    nil1 = Integer.parseInt(nilai1);
    nil2 = Integer.parseInt(nilai2);
    nil3 = Integer.parseInt(nilai3);
   
    total = (nil1+nil2+nil3)/3;
    out.println(total);
%>

Selamat mencoba.
By. http://edukasifirman.blogspot.com/