How to execute one method or another according to the word written in EditText?

Declare an array with the words, this so you don't have to write an extensive code if you need more words and write many comparisons in one line (avoid cyclomatic complexity ), it is also more optimal:

private String[] palabras = {"Hola", "Salut", "Hello"};   
private boolean palabraEncontrada = false;

performs a comparison with the text inside the EditText:

     btn1.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {


                for(String palabra: palabras){
                   if(palabra.equals(text1.getText().toString())){
                    // si la palabra es correcta:
                    Toast.makeText(MainActivity.this, "Correcto!", Toast.LENGTH_LONG).show();
                      palabraEncontrada = true;
                      break; //Si encuentra coincidencia detiene la ejecución del for.
                    }                    
                }

                if(!palabraEncontrada){ //no se encontro coincidencia.
                   // si la palabra no es correcta o no se ha escrito nada:
                    Toast.makeText(MainActivity.this, "No es correcto", 
                    Toast.LENGTH_LONG).show();
                 } else {
                    palabraEncontrada = false; // reinicia estado de variable.
                 }                        


                }
            });

and even if you use an Array you can use :

btn1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        // si la palabra es correcta:
        if(Arrays.asList(palabras).contains(text1.getText().toString())){
            Toast.makeText(MainActivity.this, "Correcto!", Toast.LENGTH_LONG).show();
        }else{
            // si la palabra no es correcta o no se ha escrito nada:
            Toast.makeText(MainActivity.this, "No es correcto", Toast.LENGTH_LONG).show();
        }


    }
});

You can try using an Array with the response words (options), and then use Arrays.asList(yourArray).contains(yourValue) to see if the word you typed in the EditText is within the correct options.

It would be something like this:

public class Main5Activity extends AppCompatActivity {

EditText text1;
Button btn1;
String[] correctAnswers = {"Hola", "Salut", "Hello"};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main5);

    text1 = (EditText) findViewById(R.id.text1);
    btn1 = (Button) findViewById(R.id.btn1);

    btn1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String answer = text1.getText().toString();

            // si la palabra es correcta:
            if(Arrays.asList(correctAnswers).contains(answer)){
                Toast.makeText(Main5Activity.this, "Correcto!", Toast.LENGTH_LONG).show();        
            }else{
            // si la palabra no es correcta o no se ha escrito nada:
                Toast.makeText(Main5Activity.this, "No es correcto", Toast.LENGTH_LONG).show();
            }
        }
    });
}
}

So simple:

        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if((text1.getText().toString().equals("Hola")) || (text1.getText().toString().equals("Salut")) || (text1.getText().toString().equals("Hello")))
                {
                    // si la palabra es correcta:
                   Toast.makeText(Main5Activity.this, "Correcto!", Toast.LENGTH_LONG).show();
                }
                else
                {
                    // si la palabra no es correcta o no se ha escrito nada:
                    Toast.makeText(Main5Activity.this, "No es correcto", Toast.LENGTH_LONG).show();
                }               

            }
        });

What you ask for can be done simply in a check within the button's click Listener. It would suffice to verify that the entered word is one of those three that you have put ( "Hello", "Salut" and Hello" ) using aif-else

PS: In the example I have put the check to be done regardless of the case with the function equalsIgnoreCase("hola")(if you want the words to be exactly the ones you put instead of using the function we equalsIgnoreCase("hola")would use the function equals("Hola"))

I hope it helps you!

btn1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

         if((text1.GetText().equalsIgnoreCase("hola")) || (text1.GetText().equalsIgnoreCase("salut")) || (text1.GetText().equalsIgnoreCase("hello"))){
                // si la palabra es correcta:
                metodo1 (); 
         }else{
                // si la palabra no es correcta o no se ha escrito nada:
                metodo2();
         }               
    }
});


public void metodo1(){
     Toast.makeText(Main5Activity.this, "Correcto!", Toast.LENGTH_LONG).show();

     //aqui el código que desees ejecutar         
}

public void metodo2(){
     Toast.makeText(Main5Activity.this, "No es correcto", Toast.LENGTH_LONG).show();

     //aqui el código que desees ejecutar         
}