android twitett,facebook,sms,kakaotalk share

package com.example.demo1;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.content.Intent;
import android.net.Uri;

public class MainActivity  extends Activity implements View.OnClickListener {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  Button btn =(Button) findViewById(R.id.button1);
  btn.setOnClickListener(this);
  
 }
 
 @Override
    public void onClick(View arg0) {
  /*
        new AlertDialog.Builder(this)
        .setIcon(R.drawable.ic_launcher)
        .setTitle("인사")
        .setMessage("안녕하세요!!")
        .setNeutralButton("닫기", null)
        .show();
        */
  
   showAlertDialog1();
    }
  
 
  private void showAlertDialog1() {
         final String[] cars = new String[] { "트위터", "페이스북", "카카오톡", "문자전송" };
    
         new AlertDialog.Builder(this)
             .setTitle("공유")
             .setItems(cars, new DialogInterface.OnClickListener() {
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                    
                  if(cars[which]=="문자전송")
                  {
                   /*
                  Toast.makeText(MainActivity.this,
                         "cars : " + cars[which],
                         Toast.LENGTH_SHORT)
                         .show();
                         */
                   shareSms();
                  }
                  else if(cars[which]=="트위터"){
                   
                   shareTwitter();
                  
                  }
                  else if(cars[which]=="페이스북"){
                   
                   shareFacebook();
                  
                  }
                   
                 }
             }).setNeutralButton("닫기", null).show();   
 
 
 
  }
 
  private void shareSms() {
    
    String message = "안녕하세요  http://www.iwav.co.kr ";
    String subject = "문제 제목 입니다. ";
    Intent share = new Intent(Intent.ACTION_SEND);
    share.setType("text/plain");
    share.putExtra(Intent.EXTRA_SUBJECT,subject);
         share.putExtra(Intent.EXTRA_TEXT, message);
    startActivity(Intent.createChooser(share, "문자 보내기"));
   
     }
 
 
  private void shareTwitter()
  {
  
  
   String twitterUri = "http://twitter.com/intent/tweet?text=";
   String marketUri = Uri.encode("안녕 하세요 감자 감자 http://iwav.co.kr/sub_read.html?uid=100");
   Intent shareOnTwitterIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(twitterUri + marketUri));
   startActivity(shareOnTwitterIntent);
  }
    
 
  private void shareFacebook()
  {
   
   
   
   String twitterUri = "http://m.facebook.com/sharer.php?u=";
   String marketUri = Uri.encode("http://iwav.co.kr/sub_read.html?uid=100");
   String marketMessage = Uri.encode("&t=안녕 하세요 감자 감자 ");
   Intent shareOnTwitterIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(twitterUri + marketUri+ marketMessage));
   startActivity(shareOnTwitterIntent);
  }
    
 
}