Java pass variable as reference

public String replaceDiacritic (String inputStr) {
	
	Map<String, String> replacements = new LinkedHashMap<String,String>() {{
		//Velká
		put("Á","A");
		put("Č","C");
		put("Ď","D");
		put("É","E");
		put("Ě","E");
		put("Í","I");
		put("Ň","N");
		put("Ó","O");
		put("Ř","R");
		put("Š","S");
		put("Ť","T");
		put("Ú","U");
		put("Ů","U");
		put("Ý","Y");
		put("Ž","Z");
		//Malá  "," ");
		put("á","a");
		put("č","c");
		put("ď","d");
		put("é","e");
		put("ě","e");
		put("í","i");
		put("ň","n");
		put("ó","o");
		put("ř","r");
		put("š","s");
		put("ť","t");
		put("ú","u");
		put("ů","u");
		put("ý","y");
		put("ž","z");
		}
	};
	for(Map.Entry<String, String> entry : replacements.entrySet()) {
          inputStr =  inputStr.replaceAll(entry.getKey(), entry.getValue());
         }	
	return inputStr;
}
	

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

        Spinner spinner = (Spinner) findViewById(R.id.spinner);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                this, R.array.countries_array, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);
        spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());

        Button myButton =(Button)findViewById(R.id.button1);
        myButton.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
            	
            Spinner sp =	(Spinner)findViewById(R.id.spinner);
            String spinnerString = null;
            spinnerString = sp.getSelectedItem().toString();
            int nPos = sp.getSelectedItemPosition();
            
             
                Toast.makeText(getApplicationContext(), "getSelectedItem=" + spinnerString,
                    Toast.LENGTH_LONG).show();
                Toast.makeText(getApplicationContext(), "getSelectedItemPosition=" + nPos,
                		Toast.LENGTH_LONG).show();
            }
        });
    }
}

public  class MyOnItemSelectedListener implements OnItemSelectedListener {

    public void onItemSelected(AdapterView<?> parent,
        View view, int pos, long id) {
      Toast.makeText(parent.getContext(), "Item is " +
          parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
    }

    public void onNothingSelected(AdapterView parent) {
      // Do nothing.
    }
}

<resources>
    <string name="hello">Hello World, MainComboBox!</string>
    <string name="app_name">ComboBox</string>
    <string name="prompt">Choose a country</string>
    <string-array name="countries_array">
        <item>China</item>
        <item>India</item>
        <item>USA</item>
        <item>Indonesia</item>
        <item>Brazil</item>
        <item>Pakistan</item>
        <item>Nigeria</item>
        <item>Bangladesh</item>
        <item>Russia</item>
    </string-array>    
</resources>

<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:padding="10dip"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dip"
        android:text="@string/prompt"
    />
    <Spinner 
        android:id="@+id/spinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:prompt="@string/prompt"
    />
    <Button android:text="Button" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>

</LinearLayout>

public class HoriziontalScrollActivity extends Activity {
	TextView txtV;
	Context cntx;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        txtV = (TextView)findViewById(R.id.idLabel);
        cntx = this;
        StringBuilder strBuild = new StringBuilder();

        // enter your date of birth
        Calendar dateOfYourBirth = new GregorianCalendar(1998, Calendar.SEPTEMBER, 17);
        Calendar today = Calendar.getInstance();
        int yourAge = today.get(Calendar.YEAR) - dateOfYourBirth.get(Calendar.YEAR);
        dateOfYourBirth.add(Calendar.YEAR, yourAge);
        if (today.before(dateOfYourBirth)) {
            yourAge--;
        }  
        strBuild.append("You are " + yourAge + " old!");
         txtV.setText(strBuild);
    }
}

private int _nVersionCode = 0;	
private boolean _bNewVersion = false;


// onCreate
     	 _nVersionCode   = this.getPackageManager()
     	.getPackageInfo(this.getPackageName(), 0).versionCode;
     	Log.d(String.valueOf(_nVersionCode), "versionCode");

// onStart loadPreferences
 public void loadPreferences() {
			//SharedPreferences settings = getSharedPreferences(F.PREFERENCES_NAME, 0);
			SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
		int nOldVersionCode =	settings.getInt("_nVersionCode",  0);// old vesion
		if(_nVersionCode > nOldVersionCode)
			_bNewVersion = true;
	}

// onDestroy savePreferences	
	public void savePreferences() {
			SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
			SharedPreferences.Editor editor = settings.edit();
			editor.putInt("_nVersionCode", _nVersionCode); // save current version code
			editor.commit();
	}