Question 1

Question 1 of 10
Given the following code fragment:

1. public static void decryptFile(SecretKey key, String fileName) {
2. Cipher calg = null;
3. try ( 
4. FileReader inputFS = new FileReader(fileName);
5. CipherOutputStream decStream = new CipherOutputStream(System.out, calg);
6. ){
7. calg = Cipher.getInstance("GARBAGE");
8. calg.init(Cipher.DECRYPT_MODE, key);
9. int charByte;
10. while ((charByte = inputFS.read()) != -1)
11. decStream.write((char)charByte);
12. decStream.flush();
13. } catch (Exception ex) {
14 //insert code here
15. }
16. }

Which code fragment, when inserted at line 14, will output exceptions associated with opening and/or closing resources?

Accepted Answer

System.err.println(ex.getMessage());

Answer

for(StackTraceElement trace: ex.getStackTrace())
System.err.println(trace.toString());

Answer

System.err.println(ex.getString());

Answer

for(Throwable supEx: ex.getSuppressed())
System.err.println(supEx.toString());

Question 2

Question 2 of 10
What is the difference between the Executor and ExecutorService interfaces?

Accepted Answer

The ExecutorService interface does not support the execute method.

Answer

The Executor interface only supports the submit method.

Answer

The Executor interface supports both Runnable and Callable objects.

Answer

The ExecutorService interface provides methods for lifecycle management of both Runnable and Callable objects.

Question 3

Question 3 of 10
Given the code fragment:

public static void writeFile(String fileName, String content) {
Path file = Paths.get(fileName);
Charset chars = Charset.defaultCharset();
try (BufferedWriter writer = Files.newBufferedWriter(file, chars)) {
writer.write(content);
} catch (IllegalArgumentException ex) {
System.err.print(ex);
}
}

Which three independent changes should you make to ensure the WriteFile method will compile?

Accepted Answer

Replace IllegalArgumentException with FileNotFoundException in the catch statement.

Accepted Answer

Add a throws clause to the method declaration that specifies FileNotFoundException.

Accepted Answer

Add a throws clause to the method declaration that specifies IOException.

Answer

Replace IllegalArgumentException with Exception in the catch statement.

Answer

Add IOException to the catch statement.

Answer

Add FileNotFoundException to the catch statement.

Question 4

Question 4 of 10
Examine the code fragment:

1. public static void readFile() {
2. Path file = Paths.get("test.dat");
3. Charset chars = Charset.defaultCharset();
4. try (BufferedReader reader = 
Files.newBufferedReader(file, chars)) { 5. String line = null;
6. while ((line = reader.readLine()) != null) 
7. System.out.println(line);
8. } catch (IllegalArgumentException | IOException ex) {
9. System.err.println(ex.getClass());
10. }
11. }

The test.dat file does not exist in the current directory. What is the result?

Accepted Answer

Compilation fails due to error on line 8.

Answer

class java.io.IOException

Answer

class java.lang.IllegalArgumentException

Answer

Compilation fails due to error on line 2.

Answer

class java.nio.file.NoSuchFileException

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