1Z1-805 무료 덤프문제 온라인 액세스

Given:
class Fibonacci extends RecursiveTask<Integer> {
final int n;
Fibonacci (int n) { this.n = n }
Integer compute () {
if (n <= 1)
return n;
Fibonacci f1 = new Fibonacci (n - 1);
f1.fork; // Line X
Fibonacci f2 = new Fibonacci (n - 2); // Line Y
return f2.compute() + f1.join;
}
}
Suppose that lines X and Y are transposed:
Fibonacci f2 = new Fibonacci (n - 2); // Line Y
f1.fork; // Line X
What is the likely result?

• A.The program produces the correct result, the better performance than the original.
• B.The program produces the correct result, with performance degraded to the equivalent of being single-threaded.
• C.The program produces an incorrect result
• D.An exception is thrown at runtime
• E.The program produces the correct result, with similar performance to the original
• F.The program goes into an infinite loop

Given the following incorrect program:
class MyTask extends RecursiveTask<Integer> {
final int low;
final int high;
static final int THRESHOLD = /* . . . */
MyTask (int low, int high) { this.low = low; this.high = high; }
Integer computeDirectly()/* . . . */
protected void compute() {
if (high - low <= THRESHOLD)
return computeDirectly();
int mid = (low + high) / 2;
invokeAll(new MyTask(low, mid), new MyTask(mid, high));
Which two changes make the program work correctly?

• A.The MyTask class must be modified to extend RecursiveAction instead of RecursiveTask.
• B.The midpoint computation must be altered so that it splits the workload in an optimal manner.
• C.The THRESHOLD value must be increased so that the overhead of task creation does not dominate the cost of computation.
• D.The compute () method must be changed to return an Integer result.
• E.The computeDirectly () method must be enhanced to fork () newly created tasks.
• F.Results must be retrieved from the newly created MyTask Instances and combined.

Given the code fragment:
public static void processFile () throws IOException { Try (FileReader fr = new FileReader ("logfilesrc.txt");
FileWriter fw = new FileWriter ("logfilesdst.txt") ) {
int i = fr.read();
}
}
Which statement is true?

• A.The java runtime automatically closes the FileReader Instance first and the FileWriter instance next.
• B.The java runtime automatically closes the FileWriter Instance first and the FileReader instance next.
• C.The Java runtime may close the FileReader and FileWriter instance in an intermediate manner. Developers should not rely on the order in which they are closed.
• D.The code fragment contains compilation errors.
• E.The developer needs to close the FileReader instance first and the FileWriter instance explicitly in a catch block.

Given the code fragment:
public static void main(String[] args) { Path dir = Paths.get("d:\\company");
// insert code here. Line **
for (Path entry: stream) {
System.out.println(entry.getFileName());
}
} catch (IOException e) {
System.err.println("Caught IOException: " + e.getMessage());
}
}
Which two try statements, when inserted at line 11, enable you to print files with the extensions.java, .htm, end and .jar.

• A.try (DirectoryStream<path> stream = Files.newDirectoryStream(dir, "*.{java, htm, jar}")) {
• B.try (DirectoryStream<path> stream = Files.newDirectoryStream(dir, "*.{java*, htm*, jar*}"}} {
• C.try (DirectoryStream<path> stream = Files.newDirectoryStream(dir, "*.[java, htm, jar"] }} {
• D.try (DirectoryStream<path> stream = Files.newDirectoryStream(dir, "**.{java, htm, jar}")) {

Given the code fragment:
/* method declaration */ { try {
String className = "java.lang.String";
String fieldname = "somefield";
Class c = Class.forName(className);
Field f = c.getField(fieldname);
} catch(Exception e) {
e.printStackTrace();
throw e;
}
}
Which two method declarations are valid options to replace /* method declaration */?

• A.public void getMetadat ()
• B.public void getMetadata () throws NoSuchFieldException
• C.public void getMetadata () throws Exception
• D.public void getMetadata ()
• E.public void getMetadata () throws ClassNotFoundException, NoSuchFieldException.
• F.public void getMetadata () throws classNotFoundException