どちらがメモリを使うのでしょうか？

void btn_actionPerformed(ActionEvent e) {    
    System.out.println("---DEFAULT---");
    checkMemory();
    
    System.out.println("---STRING[1000]---");
    String[] str = new String[1000];
    for(int i = 0; i < str.length; i ++) { str[i] = String.valueOf(i); }
    checkMemory();
    
    System.out.println("---ARRAYLIST[1000]---");
    ArrayList arylist = new ArrayList();
    for(int i = 0; i < 1000; i ++) { arylist.add(String.valueOf(i)); }
    checkMemory();

  }
  
  public void checkMemory() {
    Runtime runtime = Runtime.getRuntime();
    System.out.println("TotalMemory: " + runtime.totalMemory() + " bytes.");
    runtime = Runtime.getRuntime();
    System.out.println("FreeMemory:  " + runtime.freeMemory() + " bytes.");
    runtime = Runtime.getRuntime();
    long usedmemory = runtime.totalMemory() - runtime.freeMemory();
    System.out.println("Used Memory: " + usedmemory + " bytes.");
  }