Android Facebook login Using Facebook sdk3.0

First we check Facebook session in open or not Useing this

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mCurrContext = this;
setContentView(R.layout.fb_activity_main);
facebook_button = (Button) findViewById(R.id.LikeFB_Button);

Settings.addLoggingBehavior(LoggingBehavior.INCLUDE_ACCESS_TOKENS);
        fb_session = Session.openActiveSessionFromCache(mCurrContext);

If Your Facebook session in null and not open state click this button to login facebook

          Button button =(Button) findViewById(R.id.button_share);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if (fb_session != null && fb_session.isOpened()) {
makeMeRequest(fb_session);
Log.i("Facebook Login State == >", "Facebook Login State");
} else {
if (fb_session == null) {
fb_session = new Session(mCurrContext);          
       }
Session.setActiveSession(fb_session);
ConnectToFacebook();
  Log.i("Facebook not Login State == >", "Facebook Not login State");
}
}
});
   }

This methods used for Login to Facebook Session

  private void ConnectToFacebook(){
Session session = Session.getActiveSession();
        if (!session.isOpened() && !session.isClosed()) {
        Log.i("ConnectToFacebook  if == >", "ConnectToFacebook if");
        OpenRequest newSession = new Session.OpenRequest(this);
        newSession.setCallback(callback);
        session.openForRead(newSession);          
        try {
        Session.OpenRequest request = new Session.OpenRequest(this);
        request.setPermissions(Arrays.asList("email"));
        } catch (Exception e) {
        e.printStackTrace();
        }
        } else {
        Log.i("ConnectToFacebook  else == >", "ConnectToFacebook else");
            Session.openActiveSession(this, true, callback);        
        }
}

private Session.StatusCallback callback = new Session.StatusCallback() {
       public void call(final Session session, final SessionState state, final Exception exception) {
           onSessionStateChange(session, state, exception);
       }
   };
 
   private void onSessionStateChange(final Session session, SessionState state, Exception exception) {
       if (session != null && session.isOpened()) {
        makeMeRequest(session);
       }
   }
 
   private void makeMeRequest(final Session session) {
     Request request = Request.newMeRequest(session, new Request.GraphUserCallback() {
    public void onCompleted(GraphUser user, Response response) {
    try{
      //UserInfoDisplay(user);
    //FrieddsInfoDisplay(session);
       } catch (Exception e) {
    e.printStackTrace();
    }
    }
    });              
       request.executeAsync();
   }

NOTE:

InManifestfile you Implement facebook login activity like this

  <activity

            android:name="com.facebook.LoginActivity"

            android:label="@string/app_name"

            android:theme="@android:style/Theme.Translucent.NoTitleBar" />        

        <meta-data

            android:name="com.facebook.sdk.ApplicationId"

            android:value="@string/app_id" />

And your App id create create in  res/values/string

  Like this

<resources>   

    <string name="app_id">FACEBOOKAPPLICATIONID</string> 

</resources>