Maurício Linhares wrote:Veja que ele manda executar "java Miner.java", ele nem compilou ainda e mandou a JVM executar o arquivo texto com o código fonte.

Maurício Linhares wrote:Você deu o comando no código e ele funcionou? Tem certeza?

Porque faltou definir o classpath na linha de comando.

Given:

And the command-line invocation:
java Miner.java

What is the result?

A. null
B. null null
C. A ClassCastException is thrown.
D. A NullPointerException is thrown.
E. A NoClassDefFoundError is thrown.
F. An ArithmeticException is thrown.
G. An IllegalArgumentException is thrown.
H. An ArrayIndexOutOfBoundsException is thrown.

faelcavalcanti wrote:Ocorre o mesmo no uso de covarância quando tenta-se aplicar o polimorfismo, em que acontece em tempo de runtime, mas isso é só um exemplo.

Collection<Revisor> revisores = new HashSet<Revisor>();

The method setAnimal(Mamifero) in the type CadeiaAlimentar is not applicable for the arguments (Animal)

raf4ever wrote:

Estou com medo de fazer a certificação e ficar desatualizado muito rápido

Quanto a isso,nao acho q deva ser uma preocupação,pois apesar das sucessivas versões da prova,o conhecimento agregado com a certificação é permanente;acho que, melhor do que "viver de upgrades",é mais interessante partir pra outras certificações,e aumentar seu leque de conhecimento

brunohansen wrote:XXXXXXXXXXXXXXX Post Sensurado so falei merda XXXXXXXXXXXXXXXXXX

long...
Integer...

box_vararg(x, y); // needs to box and use var-args

The method box_vararg(long[]) is ambiguous for the type Vararg

As we can see, you can successfully combine var-args with either widening or boxing. Here's a review of the rules for overloading methods using widening, boxing,
and var-args:

* Primitive widening uses the "smallest" method argument possible.
* Used individually, boxing and var-args are compatible with overloading.
* You CANNOT widen from one wrapper type to another. (IS-A fails.)
* You CANNOT widen and then box. (An int can't become a Long.)
* You can box and then widen. (An int can become an Object, via Integer.)
* You can combine var-args with either widening or boxing.

andersonlfl wrote:A única coisa que eu não gostei no Head & First - Servlets e JSP é que os capítulos não são de acordo com os temas da prova da certificação como era no livro da Kathy Sierra pra SCJP. Mas de resto, eh ótimo.

5. Select the two statements that best indicate a situation with low coupling. (Choose two.)
A. The attributes of the class are all private.
B. The class refers to a small number of other objects.
C. The object contains only a small number of variables.
D. The object is referred to using an anonymous variable, not directly.
E. The reference variable is declared for an interface type, not a class. The interface provides a
small number of methods.
F. It is unlikely that changes made to one class will require any changes in another.
Answer:
® 3 E and F are correct. Only having access to a small number of methods implies limited
coupling. If the access is via a reference of interface type, it may be argued that there is
even less opportunity for coupling as the class type itself is not visible. Stating that changes
in one part of a program are unlikely to cause consequences in another part is really the
essence of low coupling. There is no such thing as an anonymous variable. Referring to
only a small number of other objects might imply low coupling, but if each object has many
methods, and all are used, then coupling is high. Variables (attributes) in a class should
usually be private, but this describes encapsulation, rather than low coupling. Of course,
good encapsulation tends to reduce coupling as a consequence.
®˚ A, B, C and D are incorrect based on the preceding treatise.
(Objective 5.1)

Coupling and Cohesion (Objective 5.1)
* Coupling refers to the degree to which one class knows about or uses members of another class.
* Loose coupling is the desirable state of having classes that are well encapsulated, minimize references to each other, and limit the breadth of API usage.
* Tight coupling is the undesirable state of having classes that break the rules of loose coupling.
* Cohesion refers to the degree in which a class has a single, well-defined role or responsibility.
* High cohesion is the desirable state of a class whose members support a single, well-focused role or responsibility.
* Low cohesion is the undesirable state of a class whose members support multiple, unfocused roles or responsibilities.

1. Which statement(s) are true? (Choose all that apply.)
A. Has-a relationships always rely on inheritance.
B. Has-a relationships always rely on instance variables.
C. Has-a relationships always require at least two class types.
D. Has-a relationships always rely on polymorphism.
E. Has-a relationships are always tightly coupled.
Answer:
® 3 B is correct.
®˚ A and D describe other OO topics. C is incorrect because a class can have an instance of
itself. E is incorrect because while has-a relationships can lead to tight coupling, it is by no
means always the case. (Objective 5.5)