INTERKONEKSI CLIENT-SERVER ANDROID

Penanganan URL dalam Android meliputi open koneksi ke web server dari perangkat mobile dan penanganan data I/O diantara keduanya. Proses yang terjadi meliputi tahapan berikut :

Ø  Setup connection

Ø  Data transfer

Ø  Closed

Android mendefinisikan java.net.HttpURLConnection, java.net.URL dan java.net.URLConnection class untuk membuat semua obyek koneksi.

Dalam penanganan URL, openConnection() digunakan untuk membuka URL, yang akan memberikan obyek HttpURLConnection. Untuk transfer data menggunakan class java.io.InputStreamReader yang akan mengirimkan data tiap karakter dari sisi server. Untuk akses dari HP Android ke Server tidak bisa menggunakan localhost / 127.0.0.1, harus menggunakan IP private atau publik.

 D.  Percobaan D.1. Latihan

 Latihan 1: Membuat aplikasi client-server

a. Design tampilan di : res/layout/main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:background="#125698"

> 

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Interkoneksi Client-Server"

/>

<LinearLayout

android:orientation="horizontal"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

> 

<TextView android:text="Username" android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>

<EditText android:id="@+id/EditText01" android:layout_width="fill_parent" android:layout_height="wrap_content"></EditText>

</LinearLayout>

<LinearLayout

android:orientation="horizontal"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

> 

<TextView android:id="@+id/TextView02"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Alamat"></TextView>

<EditText android:id="@+id/EditText02" android:layout_width="fill_parent" android:layout_height="wrap_content"></EditText>

</LinearLayout>

<Button android:id="@+id/Button01"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Proses"></Button>

<TextView android:id="@+id/TextView03" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>

</LinearLayout>

b. Buat file : latClientServer.java

package pens.edu;

import java.io.IOException;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import java.net.URLConnection;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import android.util.Log;

public class latClientServer extends Activity {

public static final String LOG_TAG ="dataBaru";

TextView txt;

EditText nm, almt;

Button proses;

String nama2, alamat2;

/** Called when the activity is first created. */ @Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

txt = (TextView) findViewById(R.id.TextView03);

nm = (EditText) findViewById (R.id.EditText01);

almt = (EditText) findViewById (R.id.EditText02);

proses = (Button) findViewById (R.id.Button01);

proses.setOnClickListener(new klikproses());

}

class klikproses implements Button.OnClickListener { public void onClick (View v) {

nama2 = nm.getText().toString();

alamat2 = almt.getText().toString();

String urlSite =

"http://192.168.41.1/proses.php?nama="+nama2+"&alamat= "+alamat2;

String str = downloadTeks (urlSite);

txt.setText(str);

Log.v(LOG_TAG,"str : " +str);

}

}

private InputStream OpenHttpConnection (String urlString) throws IOException { InputStream in = null;

int response = -1;

URL url = new URL(urlString);

URLConnection conn = url.openConnection();

try {

HttpURLConnection httpConn = (HttpURLConnection) conn; httpConn.setAllowUserInteraction(false); httpConn.setInstanceFollowRedirects(true); httpConn.setRequestMethod("GET"); //menggunakan metode GET saja httpConn.connect();

response = httpConn.getResponseCode();

if (response == HttpURLConnection.HTTP_OK) {

in = httpConn.getInputStream();

}

} catch (Exception ex) {

throw new IOException ("Error connecting");

}

return in;

}

private String downloadTeks (String URL) {

InputStream in = null;

try {

in = OpenHttpConnection (URL);

} catch (IOException e){} int charRead;

StringBuffer data = new StringBuffer();

String str = "";

try {

while ((charRead = in.read()) != -1 ){

data.append((char) charRead);

}

str = data.toString();

in.close();

} catch (IOException e) {} return str;

} //akhir downloadTeks } // akhir latClientServer

c.  Edit file AndroidManifest.xml agar bisa koneksi ke internet

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="pens.edu"

android:versionCode="1"

android:versionName="1.0">

<application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".latClientServer"

android:label="@string/app_name">

<intent-filter>

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" /> </intent-filter>

</activity>

</application>

<uses-sdk android:minSdkVersion="8" />

<uses-permission android:name="android.permission.INTERNET"/>

</manifest>

d. Buat file : proses.php yang ditaruh di server untuk memproses data dari HP Android

<?

$dtnama = $_GET["nama"];

$dtalamat = $_GET["alamat"];

echo "Nama : $dtnama";

echo "\n";

echo "Alamat : $dtalamat";

?