Прокомментируйте код

package com.example.phpmysql;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
private EditText usernameField,passwordField;
private TextView status,role,method;
 
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
 
usernameField = (EditText)findViewById(R.id.editText1);
passwordField = (EditText)findViewById(R.id.editText2);
 
status = (TextView)findViewById(R.id.textView6);
role = (TextView)findViewById(R.id.textView7);
method = (TextView)findViewById(R.id.textView9);
}
 
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
 
public void login(View view){
String username = usernameField.getText().toString();
String password = passwordField.getText().toString();
method.setText("Get Method");
new SigninActivity(this,status,role,0).execute(username,password);
 
}
 
public void loginPost(View view){
String username = usernameField.getText().toString();
String password = passwordField.getText().toString();
method.setText("Post Method");
new SigninActivity(this,status,role,1).execute(username,password);
}
}

package com.example.phpmysql;
 
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
 
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
 
import android.content.Context;
import android.os.AsyncTask;
import android.widget.TextView;
 
public class SigninActivity extends AsyncTask<String,Void,String>{
private TextView statusField,roleField;
private Context context;
private int byGetOrPost = 0;
 
//flag 0 means get and 1 means post.(By default it is get.)
public SigninActivity(Context context,TextView statusField,TextView roleField,int flag) {
this.context = context;
this.statusField = statusField;
this.roleField = roleField;
byGetOrPost = flag;
}
 
protected void onPreExecute(){
 
}
 
@Override
protected String doInBackground(String... arg0) {
if(byGetOrPost == 0){ //means by Get Method
 
try{
String username = (String)arg0[0];
String password = (String)arg0[1];
String link = "http://myphpmysqlweb.hostei.com/login.php?username="+username+"& password="+password;
 
URL url = new URL(link);
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(link));
HttpResponse response = client.execute(request);
BufferedReader in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
 
StringBuffer sb = new StringBuffer("");
String line="";
 
while ((line = in.readLine()) != null) {
sb.append(line);
break;
}
in.close();
return sb.toString();
}
 
catch(Exception e){
return new String("Exception: " + e.getMessage());
}
}
else{
try{
String username = (String)arg0[0];
String password = (String)arg0[1];
 
String link="http://myphpmysqlweb.hostei.com/loginpost.php";
String data = URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8");
data += "&" + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");
 
URL url = new URL(link);
URLConnection conn = url.openConnection();
 
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
 
wr.write( data );
wr.flush();
 
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
 
StringBuilder sb = new StringBuilder();
String line = null;
 
// Read Server Response
while((line = reader.readLine()) != null)
{
sb.append(line);
break;
}
return sb.toString();
}
catch(Exception e){
return new String("Exception: " + e.getMessage());
}
}
}
 
@Override
protected void onPostExecute(String result){
this.statusField.setText("Login Successful");
this.roleField.setText(result);
}
}

URL url = new URL(link); // Это делает то-то)))