Oracle 1z0-809 問題集

質問 1：
You have been asked to create a ResourceBundle which uses a properties file to localize an application.
Which code example specifies valid keys of menu1 and menu2 with values of File Menu and View Menu?
A. <key name = 'menu1">File Menu</key><key name = 'menu2">View Menu</key>
B. menu1, File Menu, menu2, View Menu
C. <key>menu1</key><value>File Menu</value><key>menu2</key><value>View Menu</value>
D. menu1 = File Menumenu2 = View Menu
正解：D

質問 2：
Given the code fragment:
BiFunction<Integer, Double, Integer> val = (t1, t2) -> t1 + t2; //line n1
//line n2
System.out.println(val.apply(10, 10.5));
What is the result?
A. 20.5
B. A compilation error occurs at line n2.
C. 20
D. A compilation error occurs at line n1.
正解：B

質問 3：
Given:

What is the result?
A. Hi Interface-1
B. Hi Interface-2
C. A compilation error occurs.
D. Hi MyClass
正解：D

質問 4：
Given the code fragments:

and

Which two modifications enable to sort the elements of the emps list? (Choose two.)
A. Replace line n1 withclass Person extends Comparator<Person>
B. At line n2 insert:public int compareTo (Person p, Person p2) {return p1.name.compareTo (p2.name);}
C. Replace line n1 withclass Person implements Comparator<Person>
D. At line n2 insertpublic int compare (Person p1, Person p2) {return p1.name.compareTo (p2.name);}
E. At line n2 insertpublic int compareTo (Person p) {return this.name.compareTo (p.name);}
F. Replace line n1 withclass Person implements Comparable<Person>
正解：E,F

質問 5：
Given the code fragment:
Stream<Path> files = Files.walk(Paths.get(System.getProperty("user.home"))); files.forEach (fName -> {//line n1 try { Path aPath = fName.toAbsolutePath();//line n2 System.out.println(fName + ":"
+ Files.readAttributes(aPath, Basic.File.Attributes.class).creationTime ());
} catch (IOException ex) {
ex.printStackTrace();
});
What is the result?
A. All files and directories under the home directory are listed along with their attributes.
B. The files in the home directory are listed along with their attributes.
C. A compilation error occurs at line n2.
D. A compilation error occurs at line n1.
正解：A

質問 6：
Given:
class Vehicle implements Comparable<Vehicle>{
int vno;
String name;
public Vehicle (int vno, String name) {
this.vno = vno,;
this.name = name;
}
public String toString () {
return vno + ":" + name;
}
public int compareTo(Vehicle o) {
return this.name.compareTo(o.name);
}
and this code fragment:
Set<Vehicle> vehicles = new TreeSet <> ();
vehicles.add(new Vehicle (10123, "Ford"));
vehicles.add(new Vehicle (10124, "BMW"));
System.out.println(vehicles);
What is the result?
A. A ClassCastException is thrown at run time.
B. [10124:BMW, 10123:Ford]
C. A compilation error occurs.
D. [10123:Ford, 10124:BMW]
正解：D

質問 7：
Given:
public class Counter {
public static void main (String[ ] args) {
int a = 10;
int b = -1;
assert (b >=1) : "Invalid Denominator";
int = a / b;
System.out.println (c);
}
}
What is the result of running the code with the -ea option?
A. 0
B. An AssertionError is thrown.
C. -10
D. A compilation error occurs.
正解：B

質問 8：
Given the code fragment:
LocalDate valentinesDay =LocalDate.of(2015, Month.FEBRUARY, 14);
LocalDate next15days = valentinesDay.plusDays (15);
LocalDate nextYear = next15days.plusYears(1); // line n1
System.out.println(nextYear);
What is the result?
A. A DateTimeException is thrown.
B. 2016-02-29
C. A compilation error occurs at line n1.
D. 2016-03-01
正解：C

質問 9：
Given the code fragments:
interface CourseFilter extends Predicate<String> {
public default boolean test (String str) {
return str.contains ("Java");
}
}
and
List<String> strs = Arrays.asList("Java", "Java EE", "Embedded Java");
Predicate<String> cf1 = s - > s.length() > 3;
Predicate cf2 = new CourseFilter() { //line n1
public boolean test (String s) {
return s.startsWith ("Java");
}
};
long c = strs.stream()
.filter(cf1)
.filter(cf2//line n2
.count();
System.out.println(c);
What is the result?
A. 2
B. 3
C. A compilation error occurs at line n2.
D. A compilation error occurs at line n1.
正解：C