Add element to List (Arraylist)

I rewrote your code, simplifying a few steps and worked Ok, resulting in the expected output and not only displaying the last element of FilaProcessos , check out:

import java.util.ArrayList;
import java.util.List;

public class Main {

    static List<String> filaProcessos = new ArrayList<String>();
    static List<String> filaAptos = new ArrayList<String>();

    public static void main(String[] args) {
        filaProcessos.add("um");
        filaProcessos.add("dois");
        filaProcessos.add("tres");

        verificaTodosProcessosAptos();

        for (String s : filaAptos) { 
            System.out.println(s);
        }
    }

    public static void verificaTodosProcessosAptos(){
        int i;
        for(i=0;i<filaProcessos.size();i++){
            saiDeProcessoParaAptos();
            i--;
        }
    }

    public static void saiDeProcessoParaAptos(){
        String processo = filaProcessos.get(0);
        String apto = processo;

        armazenarFilaApto(apto);
        //indiceAptos++;
        filaProcessos.remove(processo);
        //indiceProcesso--;
    }

    public static void armazenarFilaApto(String a){
        filaAptos.add(a);
    }

}

Look at my friend, I had a problem similar to this and the fault was in the lack of instance, a new object at each iteration, for example, finalized a cycle of for I have to give new in class objects .

So I realize you're using global variables, right? Then one checks where you are instantiating the apt object or another one you are using.

If apt and processes are two lists that have the same type of values you can use:

aptos.addAll(processos);

Good morning. Your methods are a bit confusing, start by simplifying them. I'll comment the code to try to explain.

public void verificaTodosProcessosAptos(){
   //Este metodo faz a mesma coisa que você quer fazer, mas sem indice (você não precisa dele)
   for(Processo proc : FilaProcessos){
       if(proc.getTempoCriacao()<TSP){
           saiDeProcessoParaAptos(prc);
       }
   }
}

//Neste método, você não precisa pegar o FilaProcessos.get(0), basta passar o processo por parâmetro, acredito que seja isto que você quer.

public void saiDeProcessoParaAptos(Processo proc){

       apto.setPid(proc.getPid());
       apto.setNome(proc.getNome());
       apto.setTempoCriacao(proc.getTempoCriacao());
       apto.setTempoExecucao(proc.getTempoExecucao());
       if (TSF == 0) 
            apto.setEsperaFila(0);
       else
            apto.setEsperaFila(TSP - apto.getTempoCriacao());
       apto.setSaidaFila(apto.getTempoCriacao() + apto.getEsperaFila());
       TSF=apto.getSaidaFila();
       armazenarFilaApto(apto);
       indiceAptos++;
       excluirFilaProcessos(proc);
       indiceProcesso--;
   }

From here on you should test your code, if you have difficulty finding the error with only logs, try debugging your project!

If you find it difficult to understand what I wrote, I will ask you to respond as much as possible.

Hugs