tag should specify a target API level Warning

EditText hEditText;

// TextChanged in onCreate

hEditText = (EditText)findViewById(R.id.idEditText);

hEditText.addTextChangedListener(new TextWatcher() {

	public void afterTextChanged(Editable str) {

	}



	public void beforeTextChanged(CharSequence s, int start, int count,

			int after) {

	}



	public void onTextChanged(CharSequence sq, int start, int before,

			int count) {

	}

});

// for locale English is default
/MyProject/res/values 
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">App English default</string>
    <string name="action_settings">Settings English default</string>
    <string name="hello_world">Hello world</string>

</resources>

// for locale Czech (cs)
/MyProject/res/values-cs
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Aplikace česky cs</string>
    <string name="action_settings">Nastavení česky</string>
    <string name="hello_world">Ahoj světe!</string>

</resources>

// for locale English US (r is region)
/MyProject/res/values-en-rUS

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">App English Us locale</string>
    <string name="action_settings">Settings English Us locale</string>
    <string name="hello_world">Hello world from USA :)</string>

</resources>

	public final static String[][]_arArOfString_1 = {
		new String[] {"bla","bla","hello world!"},
		new String[] {},
		new String[] {},
		new String[] {},
		new String[] {},
		new String[] {}
	};
String sOut = _arArOfString_1[0][2]; // hello world!

// file name MyFirstClass.java

import java.util.*;
import java.lang.Math;
import java.io.*;
import javax.swing.*;

public class MyFirstClass{ // start of program
  public static void main(String[] args) { // basic  function main

// variables and calculation
int a=2;
int b=3;
int c=Integer.parseInt(JOptionPane.showInputDialog(" Put number: ", "1"));
System.out.println("Number is: "+c);
System.out.println(a+" * "+b+" = "+(a*b));
System.out.println("a^3 "+Math.pow(a,b));

//array
int[] array_my=new int[10];
array_my[0]=3;
array_my[1]=5;
System.out.println("Number of elements "+array_my.length+" 1 + 2 element of array "+(array_my[0]+array_my[1]));

//strings
String txt="Quick red fox";
String txt2=JOptionPane.showInputDialog("Write text: ", "word");
System.out.println("Text is: "+txt2);
String[] count_of_word=txt.split(" ");
System.out.println("Length: "+txt.length()+" Count of words "+count_of_word.length);
System.out.println(txt +" -> "+txt.replace("red","brown"));
System.out.println("First 5 chars of string is: "+ txt.substring(0,5));

//for a if
for(int i=0; i<10;i++){
	if(i==3)System.out.println("i equal "+i);
	}

// file
try {
  File soubor=new File("some_file.txt");
  if(!soubor.exists()){
	System.out.println("File dont exist");
  }
  else { // utf-8 encoding
    BufferedReader in1 = new BufferedReader(new InputStreamReader(new FileInputStream(soubor),"UTF-8"));
    BufferedWriter out1 = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("zapis.txt"),"UTF-8"));
    String str;
      while ((str = in1.readLine())!=null){
        System.out.println(str);
        out1.write(str+"

");
      }
    in1.close();
    out1.close();
   }
 } catch(IOException e){System.out.println("Error " + e);}

// dir
 File pathName = new File("some_dir");
 String[] fileNames = pathName.list();
 if(pathName.exists())
 System.out.println("Name of first file in  "some_dir": "+fileNames[0]);
 else System.out.println("dir not exist");

//function
int nResult = calculateMyFc(3,5);
System.out.println("Result of function: "+nResult);

} // end of function main

// new function , you can add to end MyFc = my function
public static int calculateMyFc(int a, int b){
return (a+b);
}

} // end of class of program