Oracle 1z0-809 Exam Practice Questions (P. 5)

Given the code fragments:
class MyThread implements Runnable {
private static AtomicInteger count = new AtomicInteger (0);
public void run () {
int x = count.incrementAndGet();
System.out.print (x+" ");
}
}
and
Thread thread1 = new Thread(new MyThread());
Thread thread2 = new Thread(new MyThread());
Thread thread3 = new Thread(new MyThread());
Thread [] ta = {thread1, thread2, thread3};
for (int x= 0; x < 3; x++) {
ta[x].start();
}
Which statement is true?

Given the code fragment:
public static void main (String [ ] args) throws IOException {
BufferedReader br = new BufferedReader (new InputStremReader (System.in));
System.out.print ("Enter GDP: ");
//line 1
}
Which code fragment, when inserted at line 1, enables the code to read the GDP from the user?

Assuming that the file /data/december/log.txt does not exist and given the code fragment:

What is the result?

Given:
class Student {
String course, name, city;
public Student (String name, String course, String city) {
this.course = course; this.name = name; this.city = city;
}
public String toString() {
return course + ":" + name + ":" + city;
}
and the code fragment:
List<Student> stds = Arrays.asList(
new Student ("Jessy", "Java ME", "Chicago"),
new Student ("Helen", "Java EE", "Houston"),
new Student ("Mark", "Java ME", "Chicago"));
stds.stream()
.collect(Collectors.groupingBy(Student::getCourse))
.forEach(src, res) -> System.out.println(scr));
What is the result?

Given the code fragments:
interface CourseFilter extends Predicate<String> {
public default boolean test (String str) {
return str.equals ("Java");
}
}
and
List<String> strs = Arrays.asList("Java", "Java EE", "Java ME");
Predicate<String> cf1 = s - > s.length() > 3;
Predicate cf2 = new CourseFilter() { //line n1
public boolean test (String s) {
return s.contains ("Java");
}
};
long c = strs.stream()
.filter(cf1)
.filter(cf2 //line n2
.count();
System.out.println(c);
What is the result?