1z0-809 試験問題を無料オンラインアクセス

Given the code fragment:
public class Foo {
public static void main (String [ ] args) {
Map<Integer, String> unsortMap = new HashMap< > ( );
unsortMap.put (10, "z");
unsortMap.put (5, "b");
unsortMap.put (1, "d");
unsortMap.put (7, "e");
unsortMap.put (50, "j");
Map<Integer, String> treeMap = new TreeMap <Integer, String> (new
Comparator<Integer> ( ) {
@Override public int compare (Integer o1, Integer o2) {return o2.compareTo (o1); } } ); treeMap.putAll (unsortMap); for (Map.Entry<Integer, String> entry : treeMap.entrySet () ) { System.out.print (entry.getValue () + " ");
}
}
}
What is the result?

• A.j z e b d
• B.z b d e j
• C.d b e z j
• D.A compilation error occurs.

Which statement is true about the single abstract method of the java.util.function.Function interface?

• A.It accepts one argument and returns boolean.
• B.It accepts one argument and returns void.
• C.It accepts one argument and always produces a result of the same type as the argument.
• D.It accepts an argument and produces a result of any data type.

Given the code fragment:
String str = "Java is a programming language";
ToIntFunction<String> indexVal = str: : indexOf; //line n1
int x = indexVal.applyAsInt("Java");//line n2
System.out.println(x);
What is the result?

• A.A compilation error occurs at line n1.
• B.A compilation error occurs at line n2.
• C.0
• D.1

Given that course.txt is accessible and contains:
Course : : Java
and given the code fragment:
public static void main (String[ ] args) {
int i;
char c;
try (FileInputStream fis = new FileInputStream ("course.txt");
InputStreamReader isr = new InputStreamReader(fis);) {
while (!isr.close()) { //line n1
isr.skip(2);
i = isr.read ();
c = (char) i;
System.out.print(c);
}
} catch (Exception e) {
e.printStackTrace();
}
}
What is the result?

• A.ueJa
• B.The program prints nothing.
• C.A compilation error occurs at line n1.
• D.ur :: va

Given:
class UserException extends Exception { }
class AgeOutOfLimitException extends UserException { }
and the code fragment:
class App {
public void doRegister(String name, int age)
throws UserException, AgeOutOfLimitException {
if (name.length () < 6) {
throw new UserException ();
} else if (age >= 60) {
throw new AgeOutOfLimitException ();
} else {
System.out.println("User is registered.");
}
}
public static void main(String[ ] args) throws UserException {
App t = new App ();
t.doRegister("Mathew", 60);
}
}
What is the result?

• A.User is registered.
• B.A compilation error occurs in the main method.
• C.An AgeOutOfLimitException is thrown.
• D.A UserException is thrown.