Não consigo acessar documento do Exception e nem gerar o Javadoc

Olá, estou tentando fazer o passo a passo do Nico mas não abre a mesma tela do Exception e aparecem essas informações abaixo . Pesquisei mas fiquei mais confusa ainda! Quais versões eu realmente preciso usar tanto do Java e Eclipse para que dê tudo certo?

//  (version 1.8 : 52.0, super bit)
public class java.lang.Exception extends java.lang.Throwable {

  // Field descriptor #7 J
  static final long serialVersionUID = -3387516993124229948L;

  // Method descriptor #1 ()V
  // Stack: 1, Locals: 1
  public Exception();
    0  aload_0 [this]
    1  invokespecial java.lang.Throwable() [22]
    4  return


  // Method descriptor #2 (Ljava/lang/String;)V
  // Stack: 2, Locals: 2
  public Exception(java.lang.String arg0);
    0  aload_0 [this]
    1  aload_1 [arg0]
    2  invokespecial java.lang.Throwable(java.lang.String) [23]
    5  return


  // Method descriptor #15 (Ljava/lang/String;Ljava/lang/Throwable;)V
  // Stack: 3, Locals: 3
  public Exception(java.lang.String arg0, java.lang.Throwable arg1);
    0  aload_0 [this]
    1  aload_1 [arg0]
    2  aload_2 [arg1]
    3  invokespecial java.lang.Throwable(java.lang.String, java.lang.Throwable) [25]
    6  return


  // Method descriptor #3 (Ljava/lang/Throwable;)V
  // Stack: 2, Locals: 2
  public Exception(java.lang.Throwable arg0);
    0  aload_0 [this]
    1  aload_1 [arg0]
    2  invokespecial java.lang.Throwable(java.lang.Throwable) [24]
    5  return


  // Method descriptor #16 (Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
  // Stack: 5, Locals: 5
  protected Exception(java.lang.String arg0, java.lang.Throwable arg1, boolean arg2, boolean arg3);
     0  aload_0 [this]
     1  aload_1 [arg0]
     2  aload_2 [arg1]
     3  iload_3 [arg2]
     4  iload 4 [arg3]
     6  invokespecial java.lang.Throwable(java.lang.String, java.lang.Throwable, boolean, boolean) [26]
     9  return

}