Oracle 1Z0-804 Online Practice Questions and Exam Preparation

Oracle 1Z0-804 Online Questions & Answers

• Question 121:

  Which code fragment correctly appends "Java 7" to the end of the file /tmp/msg.txt?

  A. Filewriter w = new FileWriter("/tmp/msg.txt");
  B. append("Java 7");
  C. close();
  D. Filewriter w = new FileWriter("/tmp/msg.txt", true);
  E. append("Java 7");
  F. close();
  G. Filewriter w = new FileWriter("/tmp/msg.txt", FileWriter.MODE_APPEND);
  H. append("Java 7");
  I. close();
  J. Filewriter w = new FileWriter("/tmp/msg.txt", Writer.MODE_APPEND);
  B. append("Java 7");

  ---

  FileWriter(File file, boolean append)

  Constructs a FileWriter object given a File object.

  If the second argument is true, then bytes will be written to the end of the file rather than the beginning.

  Parameters:

  file - a File object to write to append - if true, then bytes will be written to the end of the file rather than the beginning

• Question 122:

  Given the code fragment:

  

  What is the result, if the file salesreport.dat does not exist?

  A. Compilation fails only at line 6
  B. Compilation fails only at line 13
  C. Compilation fails at line 6 and 13
  D. Class java.io.IOException
  E. Class java.io.FileNotFoundException
  D. Class java.io.IOException

  ---

  Compilation works fine.

  There will be a runtime error at line 6 (as the file salesreport.dat) does not exist.

  This will be caught as an IOException at line 17.

• Question 123:

  Given the code fragment:

  1.

  path file = path.get (args.[0])

  2.

  try {

  3.

  } / / statements here

  4.

  catch (IOException) i ) {

  5.

  }

  And a DOS-based file system:

  Which option, containing statement(s), inserted at line 3, creates the file and sets its attributes to hidden and read-only?

  A. DOSFileAttributes attrs = Files.setAttribute(file, "dos:hidden", "dos: readonly") Files.createFile(file, attrs)
  B. Files.craeteFile(file); Files.setAttribute(file, "dos:hidden", "dos:readonly");
  C. Files.createFile(file, "dos:hidden", "dos:readonly");
  D. Files.createFile(file); Files.setAttribute(file, "dos:hidden", true); Files.setAttribute(file, "dos:readonly", true);
  D. Files.createFile(file); Files.setAttribute(file, "dos:hidden", true); Files.setAttribute(file, "dos:readonly", true);

  ---

  You can set a DOS attribute using the setAttribute(Path, String, Object, LinkOption...) method, as follows:

  Path file = ...;

  Files.setAttribute(file, "dos:hidden", true);

  Note:

  setAttribute

  public static Path setAttribute(Path path,

  String attribute,

  Object value,

  LinkOption... options)

  throws IOException

  Sets the value of a file attribute.

  Reference: Interface DosFileAttribute

• Question 124:

  Given the following code fragment:

  10.

  p1 = paths.get("report.txt");

  11.

  p2 = paths.get("company");

  12.

  / / insert code here

  Which code fragment, when inserted independently at line 12, move the report.txt file to the company directory, at the same level, replacing the file if it already exists?

  A. Files.move(p1, p2, StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.ATOMIC_MOVE);
  B. Files.move(p1, p2, StandardCopyOption.REPLACE_Existing, LinkOption.NOFOLLOW_LINKS);
  C. Files.move (p1, p2, StandardCopyOption.REPLACE_EXISTING, LinkOption.NOFOLLOW_LINKS);
  D. Files.move(p1, p2, StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.copy_ATTRIBUTES, StandrardCopyOp)
  E. Files.move (p1, p2 StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.copy_ATTRIBUTES, LinkOption.NOF)
  A. Files.move(p1, p2, StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.ATOMIC_MOVE);

  ---

  Moving a file is equally as straight forward ?move(Path source, Path target, CopyOption... options);

  The available StandardCopyOptions enums available are:

  StandardCopyOption.REPLACE_EXISTING

  StandardCopyOption.ATOMIC_MOVE

  If Files.move is called with StandardCopyOption.COPY_ATTRIBUTES an UnsupportedOperationException is thrown.

• Question 125:

  Given the fragment:

  

  If thread a and thread b are running, but not completing, which two could be occurring?

  A. livelock
  B. deadlock
  C. starvation
  D. loose coupling
  E. cohesion
  A. livelock
  B. deadlock

  ---

  A: A thread often acts in response to the action of another thread. If the other thread's action is also a response to the action of another thread, then livelock may result. A thread often acts in response to the action of another thread. If the other thread's action is also a response to the action of another thread, then livelock may result.

  B: Deadlock describes a situation where two or more threads are blocked forever, waiting for each other.

• Question 126:

  Which concept allows generic collections to interoperate with java code that defines collections that use raw types?

  A. bytocode manipulation
  B. casting
  C. autoboxing
  D. auto-unboxing
  E. type erasure
  C. autoboxing

  ---

  Autoboxing, introduced in Java 5, is the automatic conversion the Java compiler makes between the primitive (basic) types and their corresponding object wrapper classes (eg, int and Integer, double and Double, etc). The underlying code that is generated is the same, but autoboxing provides a sugar coating that avoids the tedious and hard-to-read casting typically required by Java Collections, which can not be used with primitive types.

• Question 127:

  Given:

  public class Print01 {

  public static void main(String[] args) {

  double price = 24.99;

  int quantity = 2;

  String color = "Blue";

  // insert code here. Line ***

  }

  }

  Which two statements, inserted independently at line ***, enable the program to produce the following output:

  We have 002 Blue pants that cost $24.99.

  A. System.out.printf("We have %03d %s pants that cost $%3.2f.\n", quantity, color, price);
  B. System.out.printf("We have $03d $s pants that cost $$3.2f.\n", quantity, color, price);
  C. String out = String.format ("We have %03d %s pants that cost $%3.2f.\n", quantity, color, price); System.out.println(out);
  D. String out = System.out.format("We have %03d %s pants that cost $%3.2f.", quantity, color, price); System.out.println(out);
  E. System.out.format("We have %s %s pants that cost $%s.\n", quantity, color, price);
  A. System.out.printf("We have %03d %s pants that cost $%3.2f.\n", quantity, color, price);
  C. String out = String.format ("We have %03d %s pants that cost $%3.2f.\n", quantity, color, price); System.out.println(out);

• Question 128:

  Given that myfile.txt contains:

  First

  Second

  Third

  Given the following code fragment:

  public class ReadFile02 {

  public static void main(String[] args) {

  String fileName1 = "myfile.txt";

  String fileName2 = "newfile.txt";

  try (BufferedReader buffIn =

  new BufferedReader(new FileReader(fileName1));

  BufferedWriter buffOut =

  new BufferedWriter(new FileWriter(fileName2))

  ) {

  String line = ""; int count = 1;

  line = buffIn.readLine();

  while (line != null) {

  buffOut.write(count + ": " + line);

  buffOut.newLine();

  count++;

  line = buffIn.readLine();

  }

  } catch (IOException e) {

  System.out.println("Exception: " + e.getMessage());

  }

  }

  }

  What is the result?

  A. new file.txt contains: 1: First 2: Second 3: Third
  B. new file.txt contains: 1: First 2: Second 3: Third
  C. newfile.txt is empty
  D. an exception is thrown at runtime
  E. compilation fails
  A. new file.txt contains: 1: First 2: Second 3: Third

  ---

  For each line in the file myfile.text the line number and the line is written into newfile.txt.

• Question 129:

  Given the code fragment:

  public class IsContentSame {

  public static boolean isContentSame() throws IOException {

  Path p1=Paths.get("D:\\faculty\\report.txt");

  Path p2=Paths.get("C:\\student\\report.txt");

  Files.copy(p1,p2,StandardCopyOption.REPLACE_EXISTING,StandardCopyOption.COPY_

  ATTRIBUTES,LinkOption.NOFOLLOW_LINKS);

  if(Files.isSameFile(p1,p2)) {

  return true;

  } else {

  return false;

  }

  }

  public static void main(String[] args) {

  try {

  boolean flag = isContentSame();

  if(flag)

  System.out.println("Equal");

  else

  System.out.println("Not equal");

  } catch (IOException e) {

  System.err.println("Caught IOException: " + e.getMessage());

  }

  }

  }

  What is the result when the result.txt file already exists in c:\student?

  A. The program replaces the file contents and the file's attributes and prints Equal.
  B. The program replaces the file contents as well as the file attributes and prints Not equal.
  C. An unsupportedoperationException is thrown at runtime.
  D. The program replaces only the file attributes and prints Not equal.
  C. An unsupportedoperationException is thrown at runtime.

  ---

  Assuming there is a file D:\\faculty\\report.txt then this file will be copied and will be replacing C:\\student\\report.txt.

• Question 130:

  Given the following files in doc directory: And the code fragment:

  

  What is the result, if doc is present in the current directory?

  A. No output is produced.
  B. index.htm
  C. index.htm userguide.txt logo.gif
  D. index.htm service.html userguide.txt logo.gif
  B. index.htm

  ---

  The Glob search expression is defined through "glob:*.htm, html, xml" Only the file name index.htm matches this pattern.