InvocationTargetException & RuntimeException

package elf.app;

import android.app.Activi开发者_如何转开发ty;
import android.content.Intent;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.widget.EditText;

public class MainLoginActivity extends Activity {

private EditText et_UserName;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login);

    et_UserName = (EditText) findViewById(R.id.editText1);
    et_UserName.setOnKeyListener(new OnKeyListener() {
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if ((event.getAction() == KeyEvent.ACTION_DOWN)
                    && (keyCode == KeyEvent.KEYCODE_ENTER)) {
                logIn();
                return true;
            }
            return false;
        }
    });
}
public void logIn(View view) {
    logIn();
}

public void logIn() {
    String loginStr = et_UserName.getText().toString();

//      boolean valid = TCPIP.send(loginStr);
//      if(valid==true) {

        Intent intent = new Intent(this, RoomListActivity.class);
        intent.putExtra("loginUser", loginStr);
        this.startActivity(intent);
//      }


}

}

I get InvocationTargetException and RuntimeException.