mysql4me

MYSQL

CREATE TABLE IF NOT EXIST 'USUARIOS'{
    'Id_Usuario' int(10) NOT NULL AUTO_INCREMENT,
    'username' varchar(20) NOT NULL,
    'passw' varchar(20) NOT NULL,
    PRIMARY KEY('Id_Usuario')
};
-----------------------------------------------------------
<?php
function Conectarse()
{
    if (!($link=mysql_connect("localhost","root","")))
    {
        echo "Error conectando a la base de datos.";
        exit();
    }
    if (!mysql_select_db("usuarios",$link))
    {
        echo "Error seleccionando la base de datos.";
        exit();
    }
    return $link;
}
?>
-----------------------------------------------------------
<?php
include("conection.php");
$user=$_POST['Usuario'];
$pass=$_POST['Contrasena'];

$link=Conectarse();
$q=mysql_query("SELECT * FROM usuarios WHERE username='$user' AND passw='$pass'");

if($e=mysql_fetch_array($q)){
    $output[]=$e;
}

print(json_encode($output));
?>
------------------------------------------------------------------

public class Main extends Activity{
    private EditText user, pass;
    Button validar;

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        user=(EditText)findViewById(R.id.usuario);
        pass=(EditText)findViewById(R.id.password);

        validar=(Button) findViewById(R.id.btnValidar);

        validar.setOnClickListener(new OnClickListener){
        @Override

        public void onClick(View v){
            ArrayList<String> parametros = new ArrayList<String>();
            parametros.add("Usuario");
            parametros.add(user.getText().toString());
            parametros.add("Contraseña");
            parametros.add(pass.getText().toString());

            try{
                Post post = new Post();
                JSONArray datos = post.getServerData(parametros,"http://192.168.1.155/android/login.php");

                if (datos !=null && datos.length()>0){
                JSONObject json_data=datos.getJSONObject(0);
                int numRegistrados= json_data.getInt("Id_Usuario");
                if(numRegistrados>0){
                        Toast.makeText(getBaseContext(), "Usuario Correcto.", Toast.LENGTH_SHORT).show();
                }else{
                        Toast.makeText(getBaseContext(),"Usuario Incorrecto.", Toast.LENGTH_SHORT).show();
                }
              }catch(Exception e){
                Toast.makeText(getBaseContext(),"Error al conectar con el servidor.", Toast.LENGTH_SHORT).show();
              }
            }
        });


    }
----------------------------------------------------------------------------------------------------------------------------------
POST

public class Post{
    private InputStream is null;
    private String respuesta = "";

    private void conectaPost(ArrayList parametros, String URL){
        ArrayList nameValuePairs;
        try{
            HttpPost httppost=new HttpPost(URL);
            nameValuePairs= new ArrayList(),
            if (parametros!=null){
                for (int i=0; i<parametros.size() -1; i+=2)
                {
                nameValuePairs.add(newBasicNameValuePair((String)parametros.get(i),(String)parametros.get(i+)));
                }
                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                }
                HttpResponse response = httpclient.execute(httppost);
                HttpEntity entity = response.getEntity();
                is=entity.getContent();
            }catch (Exception e){
                Log.e("log_tag","Error in http connection" + e.toString());
            }finally{
            }
        }
    private void getRespuestaPost(){
        try{
            BufferedReader reader = new BufferedReader(
            new InputStreamReader(is, "iso-8859-1"),8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) ! = null){
            sb.append(line+"\n");
            }
            is.close(),
            respuesta = sb.toString();
            Log.e("log_tag","Cadena JSon" + respuesta);
        }catch (Exception e){
        Log.e("log_tag","Error converting resutl" + e.toString());
            }
        }
    @SuppressWarnings("finally")
        private JSONArray getJsonArray(){
        JSONArray jArray = null;
        try{
            jArray=new JSONArray(respuesta);
        }catch(Exception e){
        }finally{
            return jArray;
        }
    }
    public JSONArray getServerData(ArrayList parametros, String URL)
        conectaPost(parametros, URL);
        if(is !=null){
        getRespuestaPost();
    }
    if(respuesta !=null && respuesta.trim() !=""){
        return getJsonArray();
    }else{
        return null;
    }
}