1Z0-809 Free Practice Test

Given the code fragment:
List colors = Arrays.asList(“red”, “green”, “yellow”); Predicate test = n - > { System.out.println(“Searching…”);
return n.contains(“red”);
};
colors.stream()
.f ilter(c -> c.length() > 3)
.allMatch(test); What is the result?

1. A. Searching...
2. B. Searching...Searching...
3. C. Searching...Searching... Searching...
4. D. A compilation error occurs.

Correct Answer: A

Given the definition of the Book class:
<>

1. A. It demonstrates encapsulation.
2. B. It is defined using the factory design pattern.
3. C. It is defined using the singleton design pattern.
4. D. It demonstrates polymorphism.
5. E. It is an immutable class.

Correct Answer: A

Given:
< ><>>< ><>

1. A. Consumer
2. B. Predicate
3. C. Supplier
4. D. Function

Correct Answer: C

Which two statements are true about synchronization and locks? (Choose two.)

1. A. A thread automatically acquires the intrinsic lock on a synchronized statement when executed.
2. B. The intrinsic lock will be retained by a thread if return from a synchronized method is caused by an uncaught exception.
3. C. A thread exclusively owns the intrinsic lock of an object between the time it acquires the lock and the time itreleases it.
4. D. A thread automatically acquires the intrinsic lock on a synchronized method’s object when entering that method.
5. E. Threads cannot acquire intrinsic locks on classes.

Correct Answer: AB

Given the code fragments:
public class Book implements Comparator { String name;
double price; public Book () {}
public Book(String name, double price) { this.name = name;
this.price = price;
}
public int compare(Book b1, Book b2) { return b1.name.compareTo(b2.name);
}
public String toString() { return name + “:” + price;
}
}
and
Listbooks = Arrays.asList (new Book (“Beginning with Java”, 2), new book (“A
Guide to Java Tour”, 3));
Collections.sort(books, new Book()); System.out.print(books);
What is the result?

1. A. [A Guide to Java Tour:3.0, Beginning with Java:2.0]
2. B. [Beginning with Java:2, A Guide to Java Tour:3]
3. C. A compilation error occurs because the Book class does not override the abstract method compareTo().
4. D. An Exception is thrown at run time.

Correct Answer: A