Question 51
Click the Exhibit button.
11. public class Bootchy {
12. int bootch;
13. String snootch;14.
15. public Bootchy() {
16. this(”snootchy”);
17. System.out.print(”first “);
18. }
19.
20. public Bootchy(String snootch) {
21. this(420, “snootchy”);
22. System.out.print(”second “);
23. }
24.
25. public Bootchy(int bootch, String snootch) {
26. this.bootch = bootch;
27. this.snootch = snootch;
28. System.out.print(”third “);
29. }
30.
31. public static void main(String[] args) {
32. Bootchy b = new Bootchy();
33. System.out.print(b.snootch +“ “ + b.bootch);
34. }
35. }
What is the result?
A. snootchy 420 third second first
B. snootchy 420 first second third
C. first second third snootchy 420
D. third second first siiootchy 420
E. third first second snootchy 420
F. first second first third snootchy 420
Answer: D
Question 52
Given:
11. public class Test {
12. public enum Dogs {collie, harrier, shepherd};
13. public static void main(String [] args) {
14. Dogs myDog = Dogs.shepherd;
15. switch (myDog) {
16. case collie:
17. System.out.print(”collie “);
18. case default:
19. System.out.print(”retriever “);
20. case harrier:21. System.out.print(”harrier “);
22. }
23. }
24. }
‘What is the result?
A. harrier
B. shepherd
C. retriever
D. Compilation fails.
E. retriever harrier
F. An exception is thrown at runtime.
Answer: D
Question 53
Given:
12. public class Test {
13. public enum Dogs {collie, harrier};
14. public static void main(String [] args) {
15. Dogs myDog = Dogs.collie;
16. switch (myDog) {
17. case collie:
18. System.out.print(”collie “);
19. case harrier:
20. System.out.print(”harrier “);
21. }
22. }
23. }
What is the result?
A. collie
B. harrier
C. Compilation fails.
D. collie harrier
E. An exception is thrown at runtime.
Answer: D
Question 54
Given:
11. public void testIfA() {
12. if(testIfB(”True”)) {
13. System.out.println(”True”);
14. } else {
15. System.out.println(”Not true”);16. }
17. }
18. public Boolean testIfB(String str) {
19. return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?
A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.
Answer: A
Question 55
Given:
11. public static void main(String[] args) {
12. Integer i = uew Integer(1) + new Integer(2);
13. switch(i) {
14. case 3: System.out.println(”three”); break;
15. default: System.out.println(”other”); break;
16. }
17. }
‘What is the result?
A. three
B. other
C. An exception is thrown at runtime.
D. Compilation fails because of an error on line 12.
E. Compilation fails because of an error on line 13.
F. Compilation fails because of an error on line 15.
Answer: A
Question 56
Given:
11. public static void main(String[] args) {
12. String str = “null’;
13. if (str == null) {
14. System.out.println(”null”);
15. } else (str.length() == 0) {
16. System.out.println(”zero”);
17. } else {
18. System.out.println(”some”);
19. }20. }
‘What is the result?
A. null
B. zero
C. some
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
Question 57
Given:
11. Float pi = new Float(3.14f);
12.if(pi>3) {
13. System.out.print(”pi is bigger than 3. “);
14. }
15. else {
16. System.out.print(”pi is not bigger than 3. “);
17. }
18. finally {
19. System.out.println(”Have a nice day.”);
20. }
‘What is the result?
A. Compilation fails.
B. pi is bigger than 3.
C. An exception occurs at runtime.
D. pi is bigger than 3. Have a nice day.
E. pi is not bigger than 3. Have a nice day.
Answer: A
Question 58
Given:
10.int x=0;
11.int y 10;
12. do {
l3. y--;
14. ++x;
15. } while (x < 5);
16. System.out.print(x + “,“ + y);
What is the result?
A. 5,6
B. 5,5
C. 6,5D. 6,6
Answer: B
Question 59
Given:
25.intx=12;
26. while (x < 10) {
27. x--;
28. }
29. System.out.print(x);
What is the result?
A. 0
B. 10
C. 12
D. Line 29 will never be reached.
Answer: C
Question 60
Given:
35. int x= 10;
36. do {
37. x--;
38. } while(x< 10);
How many times will line 37 be executed?
A. ten times
B. zero times
C. one to me times
D. more than ten times
Answer: D
Question 61
Give:
11. public static Iterator reverse(List list) {
12. Collections.reverse(list);
13. return list.iterator();
14. }
15. public static void main(String[] args) {
16. List list = new ArrayList();
17. list.add(” 1”); list.add(”2”); list.add(”3”);
18. for (Object obj: reverse(list))
19. System.out.print(obj + “,”);20. }
‘What is the result?
A. 3,2, 1,
B. 1, 2, 3,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C
Question 62
Given:
11. public static Collection get() {
12. Collection sorted = new LinkedList();
13. sorted.add(’B”); sorted.add(”C”); sorted.add(”A”);
14. return sorted;
15. }
16. public static void main(String[] args) {
17. for (Object obj: get()) {
18. System.out.print(obj + “, “);
19. }
20. }
What is the result?
A. A, B, C,
B. B, C, A,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: B
Question 63
Given:
11. public static void main(String[] args) {
12. for (int i=0;i<= 10;i++){
13. if( i>6) break;
14. }
15. System.out.println(i);
16. }
What is the result?
A. 6
B. 7
C. 10
D. 11E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
Question 64
Given:
8. public class test {
9. public static void main(String [] a) {
10. assert a.length == 1;
11. }
12. }
Which two will produce an AssertionError? (Choose two.)
A. java test
B. java -ea test
C. java test file1
D. java -ea test file1
E. java -ea test file1 file2
F. java -ea:test test file1
Answer: BE
Question 65
Given:
12. public class AssertStuff {
13.
14. public static void main(String [] args) {
15. int x= 5;
16. int y= 7;
17.
18. assert (x> y): “stuff”;
19. System.out.println(”passed”);
20. }
21. }
And these command line invocations:
java AssertStuff
java -ea AssertStuff
What is the result?
A. passed
stuff
B. stuff
passed
C. passed
An AssertionError is thrown with the word “stuff” added to the stacktrace.
D. passed
An AssertionError is thrown without the word “stuff” added to the
stack trace.
E. passed
An AssertionException is thrown with the word “stuff” added to the
stack trace.
F. passed
An AssertionException is thrown without the word “stuff” added to the
stack trace.
Answer: C
Question 66
Click the Exhibit button.
1. public class Test {
2.
3. public static void main(String [] args) {
4. boolean assert = true;
5. if(assert) {
6. System.out.println(”assert is true”);
7. }
8. }
9.
10. }
Given:
javac -source 1.3 Test.java
What is the result?
A. Compilation fails.
B. Compilation succeeds with errors.
C. Compilation succeeds with warnings.
D. Compilation succeeds without warnings or errors.
Answer: C
Question 67
Given:
23.int z=5;
24.
25. public void stuff1(int x) {
26. assert (x> 0);
27. switch(x) {
28. case 2: x= 3;
29. default: assert false; } }30.
31. private void stuff2(int y) { assert (y < 0); }
32.
33. private void stuff3() { assert (stuff4O); }
34.
35. private boolean stuff4() { z = 6; return false; }
Which is true?
A. All of the assert statements are used appropriately.
B. Only the assert statement on line 31 is used appropriately.
C. The assert statements on lines 29 and 31 are used appropriately.
D. The assert statements on lines 26 and 29 are used appropriately.
E. The assert statements on lines 29 and 33 are used appropriately.
F. The assert statements on lines 29, 31, and 33 are used
appropriately.
G. The assert statements on lines 26, 29, and 31 are used
appropriately.
Answer: C
Question 68
Click the Exhibit button.
SomeException:
1. public class SomeException {
2. }
Class A:
1. public class A {
2. public void doSomething() { }
3. }
Class B:
1. public class B extends A {
2. public void doSomething() throws SomeException { }
3. }
Which is true about the two classes?
A. Compilation of both classes will fail.
B. Compilation of both classes will succeed.
C. Compilation of class A will fail. Compilation of class B will succeed.
D. Compilation of class B will fail. Compilation of class A will succeed.
Answer: D
Question 69
Click the Exhibit button.Class TestException
1. public class TestException extends Exception {
2. }
Class A:
1. public class A {
2.
3. public String sayHello(String name) throws TestException {
4.
5. if(name == null) {
6. throw new TestException();
7. }
8.
9. return “Hello “+ name;
10. }
11.
12. }
A programmer wants to use this code in an application:
45. A a=new A();
46. System.out.println(a.sayHello(”John”));
Which two are true? (Choose two.)
A. Class A will not compile.
B. Line 46 can throw the unchecked exception TestException.
C. Line 45 can throw the unchecked exception TestException.
D. Line 46 will compile if the enclosing method throws a TestException.
E. Line 46 will compile if enclosed in a try block, where TestException
is caught.
Answer: DE
Question 70
Given:
33. try {
34. // some code here
35. } catch (NullPointerException e1) {
36. System.out.print(”a”);
37. } catch (RuntimeException e2) {
38. System.out.print(”b”);
39. } finally {
40. System.out.print(”c”);
41. }
What is the result if a NullPointerException occurs on line 34?
A. c
B. aC. ab
D. ac
E. bc
F. abc
Answer: D
Question 71
Given:
11.classA {
12. public void process() { System.out.print(”A,”); } }
13. class B extends A {
14. public void process() throws IOException {
15. super.process();
16. System.out.print(”B,”);
17. throw new IOException();
18. } }
19. public static void main(String[] args) {
20. try { new B().process(); }
21. catch (IOException e) { System.out.println(”Exception”); } }
What is the result?
A. Exception
B. A,B,Exception
C. Compilation fails because of an error in line 20.
D. Compilation fails because of an error in line 14.
E. A NullPointerException is thrown at runtime.
Answer: D
Question 72
Given:
11.classA {
12. public void process() { System.out.print(”A “); } }
13. class B extends A {
14. public void process() throws RuntimeException {
15. super.process();
16. if (true) throw new RuntimeException();
17. System.out.print(“B”); }}
18. public static void main(String[] args) {
19. try { ((A)new B()).process(); }
20. catch (Exception e) { System.out.print(”Exception “); }
21. }
What is the result?A. Exception
B. A Exception
C. A Exception B
D. A B Exception
E. Compilation fails because of an error in line 14.
F. Compilation fails because of an error in line 19.
Answer: B
Question 73
Given:
11. static classA {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println(”B “); }
16. }
17. public static void main(String[] args) {
18.A a=new B();
19. a.process();
20.}
What is the result?
A. B
B. The code runs with no output.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
F. Compilation fails because of an error in line 19.
Answer: F
Question 74
Given:
11. static class A {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println(”B”); }
16. }
17. public static void main(String[] args) {
18. new B().process();
19. }
What is the result?
A. BB. The code runs with no output.
C. Compilation fails because of an error in line 12.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
Answer: A
Question 75
Given:
84. try {
85. ResourceConnection con = resourceFactory.getConnection();
86. Results r = con.query(”GET INFO FROM CUSTOMER”);
87. info = r.getData();
88. con.close();
89. } catch (ResourceException re) {
90. errorLog.write(re.getMessage());
91. }
92. return info;
Which is true if a ResourceException is thrown on line 86?
A. Line 92 will not execute.
B. The connection will not be retrieved in line 85.
C. The resource connection will not be closed on line 88.
D. The enclosing method will throw an exception to its caller.
Answer: C
Question 76
Click the Exhibit button.
1. public class A {
2. public void method1() {
3. B b=new B();
4. b.method2();
5. // more code here
6. }
7. }
1. public class B {
2. public void method2() {
3.C c=new C();
4. c.method3();
5. // more code here
6. }
7. }
1. public class C {
2. public void method3() {3. // more code here
4. }
5. }
Given:
25. try {
26. A a=new A();
27. a.method1();
28. } catch (Exception e) {
29. System.out.print(”an error occurred”);
30. }
Which two are true if a NullPointerException is thrown on line 3 of
class C? (Choose two.)
A. The application will crash.
B. The code on line 29 will be executed.
C. The code on line 5 of class A will execute.
D. The code on line 5 of class B will execute.
E. The exception will be propagated back to line 27.
Answer: BE
Question 77
Click the Exhibit button.
1. public class A {
2. public void method1() {
3. try {
4. B b=new B();
5. b.method2();
6. // more code here
7. } catch (TestException te) {
8. throw new RuntimeException(te);
9. }
6. }
7. }
1. public class B {
2. public void method2() throws TestException {
3. // more code here
4. }
5. }
1. public class TestException extends Exception {
2. }
Given:
31. public void method() {
32. A a=new A();
33. a.method1();34. }
Which is true if a TestException is thrown on line 3 of class B?
A. Line 33 must be called within a try block.
B. The exception thrown by method1 in class A is not required to be
caught.
C. The method declared on line 31 must be declared to throw a
RuntimeException.
D. On line 5 of class A, the call to method2 of class B does not need to
be placed in a try/catch block.
Answer: B
Question 78
Given:
11. public static void main(String[] args) {
12. try {
13. args=null;
14. args[0] = “test”;
15. System.out.println(args[0]);
16. } catch (Exception ex) {
17. System.out.println(”Exception”);
18. } catch (NullPointerException npe) {
19. System.out.println(”NullPointerException”);
20. }
21. }
What is the result?
A. test
B. Exception
C. Compilation fails.
D. NullPointerException
Answer: C
Question 79
Given:
11. static void test() throws Error {
12. if (true) throw new AssertionError();
13. System.out.print(”test “);
14. }
15. public static void main(String[] args) {
16. try { test(); }
17. catch (Exception ex) { System.out.print(”exception “); }
18. System.out.print(”elld “);
19. }What is the result?
A. end
B. Compilation fails.
C. exception end
D. exception test end
E. A Throwable is thrown by main.
F. An Exception is thrown by main.
Answer: E
Question 80
Given:
11. static void test() {
12. try {
13. String x=null;
14. System.out.print(x.toString() +“ “);
15. }
16. finally { System.out.print(“finally “); }
17. }
18. public static void main(String[] args) {
19. try { test(); }
20. catch (Exception ex) { System.out.print(”exception “); }
21. }
What is the result?
A. null
B. finally
C. null finally
D. Compilation fails.
E. finally exception
Answer: E
Question 81
Given:
11. static void test() throws RuntimeException {
12. try {
13. System.out.print(”test “);
14. throw new RuntimeException();
15. }
16. catch (Exception ex) { System.out.print(”exception “); }
17. }
18. public static void main(String[] args) {
19. try { test(); }
20. catch (RuntimeException ex) { System.out.print(”runtime “); }21. System.out.print(”end “);
22. }
What is the result?
A. test end
B. Compilation fails.
C. test runtime end
D. test exception end
E. A Throwable is thrown by main at runtime.
Answer: D
Question 82
Given a method that must ensue that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
....
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null
value?
A. assert value == null;
B. assert value !null, “value is null”;
C. if (value == null) {
throw new AssertionException(”value is null”);
D. if (value == null) {
throw new IllegalArgumentException(”value is null”);
Answer: D
Question 83
Click the Exhibit button.
10. public class ClassA {
11. public void methodA() {
12. ClassB classB = new ClassB();
13. classB.getValue();
14. }
15. }
And:
20. class ClassB {
21. public ClassC classC;
22.
23. public String getValue() {
24. return classC.getValue();
25. }26. }
And:
30. class ClassC {
31. public String value;
32.
33. public String getValue() {
34. value = “ClassB”;
35. return value;
36. }
37. }
Given:
ClassA a = new ClassA();
a.methodA();
What is the result?
A. Compilation fails.
B. ClassC is displayed.
C. The code runs with no output.
D. An exception is thrown at runtime.
Answer: D
Question 84
Given:
10. public class Foo {
11. static int[] a;
12. static { a[0]=2; }
13. public static void main( String[] args) {}
14. }
Which exception or error will be thrown when a programmer attempts
to run this code?
A. java.lang. StackOverflowError
B. java.lang.IllegalStateException
C. java.lang.ExceptionlnlnitializerError
D. java.lang.ArraylndexOutOfBoundsException
Answer: C
Question 85
Given:
10. public class ClassA {
11. public void count(int i) {
12. count(++i);
13. }
14. }And:
20. ClassA a = new ClassA();
21. a.count(3);
Which exception or error should be thrown by the virtual machine?
A. StackOverflowError
B. NullPointerException
C. NumberFormatException
D. IllegalArgumentException
E. ExceptionlnlnitializerError
Answer: A
Question 86
Given:
1. public class Boxer1 {
2. Integer i;
3. int x;
4. public Boxer1(int y) {
5. x=i+y;
6. System.out.println(x);
7. }
8. public static void main(String[] args) {
9. new Boxer1(new Integer(4));
10. }
11. }
What is the result?
A. The value “4” is printed at the command line.
B. Compilation fails because of an error in line 5.
C. Compilation fails because of an error in line 9.
D. A NullPointerException occurs at runtime.
E. A NumberFormatException occurs at runtime.
F. An IllegalStateException occurs at runtime.
Answer: D
Question 87
Given:
1. public class TestString 1 {
2. public static void main(String[] args) {
3. String str = “420”;
4. str += 42;
5. System.out.print(str);
6. }
7. }What is the output?
A. 42
B. 420
C. 462
D. 42042
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: D
Question 88
Given:
11. class Converter {
12. public static void main(String[] args) {
13. Integer i = args[0];
14. int j = 12;
15. System.out.println(”It is “ + (j==i) + “that j==i.”);
16. }
17. }
What is the result when the programmer attempts to compile the code
and run it with the command java Converter 12?
A. It is true that j==i.
B. It is false that j==i.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
Question 89
Given this method in a class:
21. public String toString() {
22. StringBuffer buffer = new StringBuffer();
23. buffer.append(’<’);
24. buffer.append(this.name);
25. buffer.append(’>’);
26. return buffer.toString();
27. }
Which is true?
A. This code is NOT thread-safe.
B. The programmer can replace StringBuffer with StringBuilder with no
other changes.
C. This code will perform well and converting the code to use
StringBuilder will not enhance the performance.
D. This code will perform poorly. For better performance, the codeshould be rewritten:
return “<“+ this.name + “>”;
Answer: B
Question 90
Given:
1. public class MyLogger {
2. private StringBuilder logger = new StringBuuilder();
3. public void log(String message, String user) {
4. logger.append(message);
5. logger.append(user);
6. }
7. }
The programmer must guarantee that a single MyLogger object works
properly for a multi-threaded system. How must this code be changed
to be thread-safe?
A. synchronize the log method
B. replace StringBuilder with StringBuffer
C. No change is necessary, the current MyLogger code is already
thread-safe.
D. replace StringBuilder with just a String object and use the string
concatenation (+=) within the log method
Answer: A
Question 91
Given:
11. public String makinStrings() {
12. String s = “Fred”;
13. s = s + “47”;
14. s = s.substring(2, 5);
15. s = s.toUpperCase();
16. return s.toString();
17. }
How many String objects will be created when this method is invoked?
A. 1
B. 2
C. 3
D. 4
E. 5
F. 6
Answer: CQuestion 92
Given:
1. public class TestString3 {
2. public static void main(String[] args) {
3. // insert code here
5. System.out.println(s);
6. }
7. }
Which two code fragments, inserted independently at line 3, generate
the output 4247? (Choose two.)
A. String s = “123456789”;
s = (s-”123”).replace(1,3,”24”) - “89”;
B. StringBuffer s = new StringBuffer(”123456789”);
s.delete(0,3).replace( 1,3, “24”).delete(4,6);
C. StringBuffer s = new StringBuffer(”123456789”);
s.substring(3,6).delete( 1 ,3).insert( 1, “24”);
D. StringBuilder s = new StringBuilder(”123456789”);
s.substring(3,6).delete( 1 ,2).insert( 1, “24”);
E. StringBuilder s = new StringBuilder(”123456789”);
s.delete(0,3).delete( 1 ,3).delete(2,5).insert( 1, “24”);
Answer: BE
Question 93
Given:
11. public class Yikes {
12.
13. public static void go(Long n) {System.out.println(”Long “);}
14. public static void go(Short n) {System.out.println(”Short “);}
15. public static void go(int n) {System.out.println(”int “);}
16. public static void main(String [] args) {
17. short y= 6;
18. long z= 7;
19. go(y);
20. go(z);
21. }
22. }
What is the result?
A. int LongB. Short Long
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: A
Question 94
Given:
12. public class Wow {
13. public static void go(short n) {System.out.println(”short”); }
14. public static void go(Short n) {System.out.println(”SHORT”);}
15. public static void go(Long n) {System.out.println(” LONG”); }
16. public static void main(String [] args) {
17. Short y= 6;
18.int z=7;
19. go(y);
20. go(z);
21. }
22. }
What is the result?
A. short LONG
B. SHORT LONG
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: C
Question 95
Given:
10. class MakeFile {
11. public static void main(String[] args) {
12. try {
13. File directory = new File(”d”);
14. File file = new File(directory,”f”);
15. if(!file.exists()) {
16. file.createNewFile();
17. }
18. } catch (IOException e) {
19. e.printStackTrace
20. }
21. }
22. }
The current directory does NOT contain a directory named “d.”
Which three are true? (Choose three.)A. Line 16 is never executed.
B. An exception is thrown at runtime.
C. Line 13 creates a File object named “d.”
D. Line 14 creates a File object named “f.’
E. Line 13 creates a directory named “d” in the file system.
F. Line 16 creates a directory named “d” and a file ‘f’ within it in the
file system.
G. Line 14 creates a file named ‘f’ inside of the directory named “d” in
the file system.
Answer: BCD
Question 96
When comparing java.io.BufferedWriter to java.io.FileWriter, which
capability exists as a method in only one of the two?
A. closing the stream
B. flushing the stream
C. writing to the stream
D. marking a location in the stream
E. writing a line separator to the stream
Answer: E
Question 97
Given:
12. import java.io.*;
13. public class Forest implements Serializable {
14. private Tree tree = new Tree();
15. public static void main(String [] args) {
16. Forest f= new Forest();
17. try {
18. FileOutputStream fs = new FileOutputStream(”Forest.ser”);
19. ObjectOutputStream os = new ObjectOutputStream(fs);
20. os.writeObject(f); os.close();
21. } catch (Exception ex) { ex.printStackTrace(); }
22. } }
23.
24. class Tree { }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. An instance of Forest is serialized.
D. A instance of Forest and an instance of Tree are both serialized.Answer: B
Question 98
Click the Exhibit button.
1. import java.io.*;
2. public class Foo implements Serializable {
3. public int x, y;
4. public Foo( int x, int y) { this.x = x; this.y = y; }
5.
6. private void writeObject( ObjectOutputStream s)
7. throws IOException {
8. s.writeInt(x); s.writeInt(y)
9. }
10.
11. private void readObject( ObjectInputStream s)
12. throws IOException, ClassNotFoundException {
13.
14. // insert code here
15.
16. }
17. }
Which code, inserted at line 14, will allow this class to correctly
serialize and deserialize?
A. s.defaultReadObject();
B. this = s.defaultReadObject();
C. y = s.readInt(); x = s.readInt();
D. x = s.readInt(); y = s.readInt();
Answer: D
Question 99
Which three concerning the use of the java.io.Serializable interface are
true? (Choose three.)
A. Objects from classes that use aggregation cannot be serialized.
B. Art object serialized on one JVM can be successfully deserialized on
a different JVM.
C. The values in fields with the volatile modifier will NOT survive
serialization and deserialization.
D. The values in fields with the transient modifier will NOT survive
serialization and deserialization.
E. It is legal to serialize an object of a type that has a supertype that
does NOT implement java.io.Serializable.Answer: BDE
Question 100
Assuming that the serializeBanana() and the deserializeBanana()
methods will correctly use Java serialization and given:
13. import java.io.*;
14. class Food implemertts Serializable {int good = 3;}
15. class Fruit externds Food {int juice = 5;}
16. public class Banana extends Fruit {
17. int yellow = 4;
18. public static void main(String [] args) {
19. Banana b = new Banana(); Banana b2 = new Banana();
20. b.serializeBanana(b);
// assume correct serialization
21. b2 = b.deserializeBanana();
// assume correct
22. System.out.println(”restore “+b2.yellow+ b2.juice+b2.good);
24. }
25. // more Banana methods go here
50. }
‘What is the result?
A. restore 400
B. restore 403
C. restore 453
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: C
Click the Exhibit button.
11. public class Bootchy {
12. int bootch;
13. String snootch;14.
15. public Bootchy() {
16. this(”snootchy”);
17. System.out.print(”first “);
18. }
19.
20. public Bootchy(String snootch) {
21. this(420, “snootchy”);
22. System.out.print(”second “);
23. }
24.
25. public Bootchy(int bootch, String snootch) {
26. this.bootch = bootch;
27. this.snootch = snootch;
28. System.out.print(”third “);
29. }
30.
31. public static void main(String[] args) {
32. Bootchy b = new Bootchy();
33. System.out.print(b.snootch +“ “ + b.bootch);
34. }
35. }
What is the result?
A. snootchy 420 third second first
B. snootchy 420 first second third
C. first second third snootchy 420
D. third second first siiootchy 420
E. third first second snootchy 420
F. first second first third snootchy 420
Answer: D
Question 52
Given:
11. public class Test {
12. public enum Dogs {collie, harrier, shepherd};
13. public static void main(String [] args) {
14. Dogs myDog = Dogs.shepherd;
15. switch (myDog) {
16. case collie:
17. System.out.print(”collie “);
18. case default:
19. System.out.print(”retriever “);
20. case harrier:21. System.out.print(”harrier “);
22. }
23. }
24. }
‘What is the result?
A. harrier
B. shepherd
C. retriever
D. Compilation fails.
E. retriever harrier
F. An exception is thrown at runtime.
Answer: D
Question 53
Given:
12. public class Test {
13. public enum Dogs {collie, harrier};
14. public static void main(String [] args) {
15. Dogs myDog = Dogs.collie;
16. switch (myDog) {
17. case collie:
18. System.out.print(”collie “);
19. case harrier:
20. System.out.print(”harrier “);
21. }
22. }
23. }
What is the result?
A. collie
B. harrier
C. Compilation fails.
D. collie harrier
E. An exception is thrown at runtime.
Answer: D
Question 54
Given:
11. public void testIfA() {
12. if(testIfB(”True”)) {
13. System.out.println(”True”);
14. } else {
15. System.out.println(”Not true”);16. }
17. }
18. public Boolean testIfB(String str) {
19. return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?
A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.
Answer: A
Question 55
Given:
11. public static void main(String[] args) {
12. Integer i = uew Integer(1) + new Integer(2);
13. switch(i) {
14. case 3: System.out.println(”three”); break;
15. default: System.out.println(”other”); break;
16. }
17. }
‘What is the result?
A. three
B. other
C. An exception is thrown at runtime.
D. Compilation fails because of an error on line 12.
E. Compilation fails because of an error on line 13.
F. Compilation fails because of an error on line 15.
Answer: A
Question 56
Given:
11. public static void main(String[] args) {
12. String str = “null’;
13. if (str == null) {
14. System.out.println(”null”);
15. } else (str.length() == 0) {
16. System.out.println(”zero”);
17. } else {
18. System.out.println(”some”);
19. }20. }
‘What is the result?
A. null
B. zero
C. some
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
Question 57
Given:
11. Float pi = new Float(3.14f);
12.if(pi>3) {
13. System.out.print(”pi is bigger than 3. “);
14. }
15. else {
16. System.out.print(”pi is not bigger than 3. “);
17. }
18. finally {
19. System.out.println(”Have a nice day.”);
20. }
‘What is the result?
A. Compilation fails.
B. pi is bigger than 3.
C. An exception occurs at runtime.
D. pi is bigger than 3. Have a nice day.
E. pi is not bigger than 3. Have a nice day.
Answer: A
Question 58
Given:
10.int x=0;
11.int y 10;
12. do {
l3. y--;
14. ++x;
15. } while (x < 5);
16. System.out.print(x + “,“ + y);
What is the result?
A. 5,6
B. 5,5
C. 6,5D. 6,6
Answer: B
Question 59
Given:
25.intx=12;
26. while (x < 10) {
27. x--;
28. }
29. System.out.print(x);
What is the result?
A. 0
B. 10
C. 12
D. Line 29 will never be reached.
Answer: C
Question 60
Given:
35. int x= 10;
36. do {
37. x--;
38. } while(x< 10);
How many times will line 37 be executed?
A. ten times
B. zero times
C. one to me times
D. more than ten times
Answer: D
Question 61
Give:
11. public static Iterator reverse(List list) {
12. Collections.reverse(list);
13. return list.iterator();
14. }
15. public static void main(String[] args) {
16. List list = new ArrayList();
17. list.add(” 1”); list.add(”2”); list.add(”3”);
18. for (Object obj: reverse(list))
19. System.out.print(obj + “,”);20. }
‘What is the result?
A. 3,2, 1,
B. 1, 2, 3,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C
Question 62
Given:
11. public static Collection get() {
12. Collection sorted = new LinkedList();
13. sorted.add(’B”); sorted.add(”C”); sorted.add(”A”);
14. return sorted;
15. }
16. public static void main(String[] args) {
17. for (Object obj: get()) {
18. System.out.print(obj + “, “);
19. }
20. }
What is the result?
A. A, B, C,
B. B, C, A,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: B
Question 63
Given:
11. public static void main(String[] args) {
12. for (int i=0;i<= 10;i++){
13. if( i>6) break;
14. }
15. System.out.println(i);
16. }
What is the result?
A. 6
B. 7
C. 10
D. 11E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
Question 64
Given:
8. public class test {
9. public static void main(String [] a) {
10. assert a.length == 1;
11. }
12. }
Which two will produce an AssertionError? (Choose two.)
A. java test
B. java -ea test
C. java test file1
D. java -ea test file1
E. java -ea test file1 file2
F. java -ea:test test file1
Answer: BE
Question 65
Given:
12. public class AssertStuff {
13.
14. public static void main(String [] args) {
15. int x= 5;
16. int y= 7;
17.
18. assert (x> y): “stuff”;
19. System.out.println(”passed”);
20. }
21. }
And these command line invocations:
java AssertStuff
java -ea AssertStuff
What is the result?
A. passed
stuff
B. stuff
passed
C. passed
An AssertionError is thrown with the word “stuff” added to the stacktrace.
D. passed
An AssertionError is thrown without the word “stuff” added to the
stack trace.
E. passed
An AssertionException is thrown with the word “stuff” added to the
stack trace.
F. passed
An AssertionException is thrown without the word “stuff” added to the
stack trace.
Answer: C
Question 66
Click the Exhibit button.
1. public class Test {
2.
3. public static void main(String [] args) {
4. boolean assert = true;
5. if(assert) {
6. System.out.println(”assert is true”);
7. }
8. }
9.
10. }
Given:
javac -source 1.3 Test.java
What is the result?
A. Compilation fails.
B. Compilation succeeds with errors.
C. Compilation succeeds with warnings.
D. Compilation succeeds without warnings or errors.
Answer: C
Question 67
Given:
23.int z=5;
24.
25. public void stuff1(int x) {
26. assert (x> 0);
27. switch(x) {
28. case 2: x= 3;
29. default: assert false; } }30.
31. private void stuff2(int y) { assert (y < 0); }
32.
33. private void stuff3() { assert (stuff4O); }
34.
35. private boolean stuff4() { z = 6; return false; }
Which is true?
A. All of the assert statements are used appropriately.
B. Only the assert statement on line 31 is used appropriately.
C. The assert statements on lines 29 and 31 are used appropriately.
D. The assert statements on lines 26 and 29 are used appropriately.
E. The assert statements on lines 29 and 33 are used appropriately.
F. The assert statements on lines 29, 31, and 33 are used
appropriately.
G. The assert statements on lines 26, 29, and 31 are used
appropriately.
Answer: C
Question 68
Click the Exhibit button.
SomeException:
1. public class SomeException {
2. }
Class A:
1. public class A {
2. public void doSomething() { }
3. }
Class B:
1. public class B extends A {
2. public void doSomething() throws SomeException { }
3. }
Which is true about the two classes?
A. Compilation of both classes will fail.
B. Compilation of both classes will succeed.
C. Compilation of class A will fail. Compilation of class B will succeed.
D. Compilation of class B will fail. Compilation of class A will succeed.
Answer: D
Question 69
Click the Exhibit button.Class TestException
1. public class TestException extends Exception {
2. }
Class A:
1. public class A {
2.
3. public String sayHello(String name) throws TestException {
4.
5. if(name == null) {
6. throw new TestException();
7. }
8.
9. return “Hello “+ name;
10. }
11.
12. }
A programmer wants to use this code in an application:
45. A a=new A();
46. System.out.println(a.sayHello(”John”));
Which two are true? (Choose two.)
A. Class A will not compile.
B. Line 46 can throw the unchecked exception TestException.
C. Line 45 can throw the unchecked exception TestException.
D. Line 46 will compile if the enclosing method throws a TestException.
E. Line 46 will compile if enclosed in a try block, where TestException
is caught.
Answer: DE
Question 70
Given:
33. try {
34. // some code here
35. } catch (NullPointerException e1) {
36. System.out.print(”a”);
37. } catch (RuntimeException e2) {
38. System.out.print(”b”);
39. } finally {
40. System.out.print(”c”);
41. }
What is the result if a NullPointerException occurs on line 34?
A. c
B. aC. ab
D. ac
E. bc
F. abc
Answer: D
Question 71
Given:
11.classA {
12. public void process() { System.out.print(”A,”); } }
13. class B extends A {
14. public void process() throws IOException {
15. super.process();
16. System.out.print(”B,”);
17. throw new IOException();
18. } }
19. public static void main(String[] args) {
20. try { new B().process(); }
21. catch (IOException e) { System.out.println(”Exception”); } }
What is the result?
A. Exception
B. A,B,Exception
C. Compilation fails because of an error in line 20.
D. Compilation fails because of an error in line 14.
E. A NullPointerException is thrown at runtime.
Answer: D
Question 72
Given:
11.classA {
12. public void process() { System.out.print(”A “); } }
13. class B extends A {
14. public void process() throws RuntimeException {
15. super.process();
16. if (true) throw new RuntimeException();
17. System.out.print(“B”); }}
18. public static void main(String[] args) {
19. try { ((A)new B()).process(); }
20. catch (Exception e) { System.out.print(”Exception “); }
21. }
What is the result?A. Exception
B. A Exception
C. A Exception B
D. A B Exception
E. Compilation fails because of an error in line 14.
F. Compilation fails because of an error in line 19.
Answer: B
Question 73
Given:
11. static classA {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println(”B “); }
16. }
17. public static void main(String[] args) {
18.A a=new B();
19. a.process();
20.}
What is the result?
A. B
B. The code runs with no output.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
F. Compilation fails because of an error in line 19.
Answer: F
Question 74
Given:
11. static class A {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println(”B”); }
16. }
17. public static void main(String[] args) {
18. new B().process();
19. }
What is the result?
A. BB. The code runs with no output.
C. Compilation fails because of an error in line 12.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
Answer: A
Question 75
Given:
84. try {
85. ResourceConnection con = resourceFactory.getConnection();
86. Results r = con.query(”GET INFO FROM CUSTOMER”);
87. info = r.getData();
88. con.close();
89. } catch (ResourceException re) {
90. errorLog.write(re.getMessage());
91. }
92. return info;
Which is true if a ResourceException is thrown on line 86?
A. Line 92 will not execute.
B. The connection will not be retrieved in line 85.
C. The resource connection will not be closed on line 88.
D. The enclosing method will throw an exception to its caller.
Answer: C
Question 76
Click the Exhibit button.
1. public class A {
2. public void method1() {
3. B b=new B();
4. b.method2();
5. // more code here
6. }
7. }
1. public class B {
2. public void method2() {
3.C c=new C();
4. c.method3();
5. // more code here
6. }
7. }
1. public class C {
2. public void method3() {3. // more code here
4. }
5. }
Given:
25. try {
26. A a=new A();
27. a.method1();
28. } catch (Exception e) {
29. System.out.print(”an error occurred”);
30. }
Which two are true if a NullPointerException is thrown on line 3 of
class C? (Choose two.)
A. The application will crash.
B. The code on line 29 will be executed.
C. The code on line 5 of class A will execute.
D. The code on line 5 of class B will execute.
E. The exception will be propagated back to line 27.
Answer: BE
Question 77
Click the Exhibit button.
1. public class A {
2. public void method1() {
3. try {
4. B b=new B();
5. b.method2();
6. // more code here
7. } catch (TestException te) {
8. throw new RuntimeException(te);
9. }
6. }
7. }
1. public class B {
2. public void method2() throws TestException {
3. // more code here
4. }
5. }
1. public class TestException extends Exception {
2. }
Given:
31. public void method() {
32. A a=new A();
33. a.method1();34. }
Which is true if a TestException is thrown on line 3 of class B?
A. Line 33 must be called within a try block.
B. The exception thrown by method1 in class A is not required to be
caught.
C. The method declared on line 31 must be declared to throw a
RuntimeException.
D. On line 5 of class A, the call to method2 of class B does not need to
be placed in a try/catch block.
Answer: B
Question 78
Given:
11. public static void main(String[] args) {
12. try {
13. args=null;
14. args[0] = “test”;
15. System.out.println(args[0]);
16. } catch (Exception ex) {
17. System.out.println(”Exception”);
18. } catch (NullPointerException npe) {
19. System.out.println(”NullPointerException”);
20. }
21. }
What is the result?
A. test
B. Exception
C. Compilation fails.
D. NullPointerException
Answer: C
Question 79
Given:
11. static void test() throws Error {
12. if (true) throw new AssertionError();
13. System.out.print(”test “);
14. }
15. public static void main(String[] args) {
16. try { test(); }
17. catch (Exception ex) { System.out.print(”exception “); }
18. System.out.print(”elld “);
19. }What is the result?
A. end
B. Compilation fails.
C. exception end
D. exception test end
E. A Throwable is thrown by main.
F. An Exception is thrown by main.
Answer: E
Question 80
Given:
11. static void test() {
12. try {
13. String x=null;
14. System.out.print(x.toString() +“ “);
15. }
16. finally { System.out.print(“finally “); }
17. }
18. public static void main(String[] args) {
19. try { test(); }
20. catch (Exception ex) { System.out.print(”exception “); }
21. }
What is the result?
A. null
B. finally
C. null finally
D. Compilation fails.
E. finally exception
Answer: E
Question 81
Given:
11. static void test() throws RuntimeException {
12. try {
13. System.out.print(”test “);
14. throw new RuntimeException();
15. }
16. catch (Exception ex) { System.out.print(”exception “); }
17. }
18. public static void main(String[] args) {
19. try { test(); }
20. catch (RuntimeException ex) { System.out.print(”runtime “); }21. System.out.print(”end “);
22. }
What is the result?
A. test end
B. Compilation fails.
C. test runtime end
D. test exception end
E. A Throwable is thrown by main at runtime.
Answer: D
Question 82
Given a method that must ensue that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
....
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null
value?
A. assert value == null;
B. assert value !null, “value is null”;
C. if (value == null) {
throw new AssertionException(”value is null”);
D. if (value == null) {
throw new IllegalArgumentException(”value is null”);
Answer: D
Question 83
Click the Exhibit button.
10. public class ClassA {
11. public void methodA() {
12. ClassB classB = new ClassB();
13. classB.getValue();
14. }
15. }
And:
20. class ClassB {
21. public ClassC classC;
22.
23. public String getValue() {
24. return classC.getValue();
25. }26. }
And:
30. class ClassC {
31. public String value;
32.
33. public String getValue() {
34. value = “ClassB”;
35. return value;
36. }
37. }
Given:
ClassA a = new ClassA();
a.methodA();
What is the result?
A. Compilation fails.
B. ClassC is displayed.
C. The code runs with no output.
D. An exception is thrown at runtime.
Answer: D
Question 84
Given:
10. public class Foo {
11. static int[] a;
12. static { a[0]=2; }
13. public static void main( String[] args) {}
14. }
Which exception or error will be thrown when a programmer attempts
to run this code?
A. java.lang. StackOverflowError
B. java.lang.IllegalStateException
C. java.lang.ExceptionlnlnitializerError
D. java.lang.ArraylndexOutOfBoundsException
Answer: C
Question 85
Given:
10. public class ClassA {
11. public void count(int i) {
12. count(++i);
13. }
14. }And:
20. ClassA a = new ClassA();
21. a.count(3);
Which exception or error should be thrown by the virtual machine?
A. StackOverflowError
B. NullPointerException
C. NumberFormatException
D. IllegalArgumentException
E. ExceptionlnlnitializerError
Answer: A
Question 86
Given:
1. public class Boxer1 {
2. Integer i;
3. int x;
4. public Boxer1(int y) {
5. x=i+y;
6. System.out.println(x);
7. }
8. public static void main(String[] args) {
9. new Boxer1(new Integer(4));
10. }
11. }
What is the result?
A. The value “4” is printed at the command line.
B. Compilation fails because of an error in line 5.
C. Compilation fails because of an error in line 9.
D. A NullPointerException occurs at runtime.
E. A NumberFormatException occurs at runtime.
F. An IllegalStateException occurs at runtime.
Answer: D
Question 87
Given:
1. public class TestString 1 {
2. public static void main(String[] args) {
3. String str = “420”;
4. str += 42;
5. System.out.print(str);
6. }
7. }What is the output?
A. 42
B. 420
C. 462
D. 42042
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: D
Question 88
Given:
11. class Converter {
12. public static void main(String[] args) {
13. Integer i = args[0];
14. int j = 12;
15. System.out.println(”It is “ + (j==i) + “that j==i.”);
16. }
17. }
What is the result when the programmer attempts to compile the code
and run it with the command java Converter 12?
A. It is true that j==i.
B. It is false that j==i.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
Question 89
Given this method in a class:
21. public String toString() {
22. StringBuffer buffer = new StringBuffer();
23. buffer.append(’<’);
24. buffer.append(this.name);
25. buffer.append(’>’);
26. return buffer.toString();
27. }
Which is true?
A. This code is NOT thread-safe.
B. The programmer can replace StringBuffer with StringBuilder with no
other changes.
C. This code will perform well and converting the code to use
StringBuilder will not enhance the performance.
D. This code will perform poorly. For better performance, the codeshould be rewritten:
return “<“+ this.name + “>”;
Answer: B
Question 90
Given:
1. public class MyLogger {
2. private StringBuilder logger = new StringBuuilder();
3. public void log(String message, String user) {
4. logger.append(message);
5. logger.append(user);
6. }
7. }
The programmer must guarantee that a single MyLogger object works
properly for a multi-threaded system. How must this code be changed
to be thread-safe?
A. synchronize the log method
B. replace StringBuilder with StringBuffer
C. No change is necessary, the current MyLogger code is already
thread-safe.
D. replace StringBuilder with just a String object and use the string
concatenation (+=) within the log method
Answer: A
Question 91
Given:
11. public String makinStrings() {
12. String s = “Fred”;
13. s = s + “47”;
14. s = s.substring(2, 5);
15. s = s.toUpperCase();
16. return s.toString();
17. }
How many String objects will be created when this method is invoked?
A. 1
B. 2
C. 3
D. 4
E. 5
F. 6
Answer: CQuestion 92
Given:
1. public class TestString3 {
2. public static void main(String[] args) {
3. // insert code here
5. System.out.println(s);
6. }
7. }
Which two code fragments, inserted independently at line 3, generate
the output 4247? (Choose two.)
A. String s = “123456789”;
s = (s-”123”).replace(1,3,”24”) - “89”;
B. StringBuffer s = new StringBuffer(”123456789”);
s.delete(0,3).replace( 1,3, “24”).delete(4,6);
C. StringBuffer s = new StringBuffer(”123456789”);
s.substring(3,6).delete( 1 ,3).insert( 1, “24”);
D. StringBuilder s = new StringBuilder(”123456789”);
s.substring(3,6).delete( 1 ,2).insert( 1, “24”);
E. StringBuilder s = new StringBuilder(”123456789”);
s.delete(0,3).delete( 1 ,3).delete(2,5).insert( 1, “24”);
Answer: BE
Question 93
Given:
11. public class Yikes {
12.
13. public static void go(Long n) {System.out.println(”Long “);}
14. public static void go(Short n) {System.out.println(”Short “);}
15. public static void go(int n) {System.out.println(”int “);}
16. public static void main(String [] args) {
17. short y= 6;
18. long z= 7;
19. go(y);
20. go(z);
21. }
22. }
What is the result?
A. int LongB. Short Long
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: A
Question 94
Given:
12. public class Wow {
13. public static void go(short n) {System.out.println(”short”); }
14. public static void go(Short n) {System.out.println(”SHORT”);}
15. public static void go(Long n) {System.out.println(” LONG”); }
16. public static void main(String [] args) {
17. Short y= 6;
18.int z=7;
19. go(y);
20. go(z);
21. }
22. }
What is the result?
A. short LONG
B. SHORT LONG
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: C
Question 95
Given:
10. class MakeFile {
11. public static void main(String[] args) {
12. try {
13. File directory = new File(”d”);
14. File file = new File(directory,”f”);
15. if(!file.exists()) {
16. file.createNewFile();
17. }
18. } catch (IOException e) {
19. e.printStackTrace
20. }
21. }
22. }
The current directory does NOT contain a directory named “d.”
Which three are true? (Choose three.)A. Line 16 is never executed.
B. An exception is thrown at runtime.
C. Line 13 creates a File object named “d.”
D. Line 14 creates a File object named “f.’
E. Line 13 creates a directory named “d” in the file system.
F. Line 16 creates a directory named “d” and a file ‘f’ within it in the
file system.
G. Line 14 creates a file named ‘f’ inside of the directory named “d” in
the file system.
Answer: BCD
Question 96
When comparing java.io.BufferedWriter to java.io.FileWriter, which
capability exists as a method in only one of the two?
A. closing the stream
B. flushing the stream
C. writing to the stream
D. marking a location in the stream
E. writing a line separator to the stream
Answer: E
Question 97
Given:
12. import java.io.*;
13. public class Forest implements Serializable {
14. private Tree tree = new Tree();
15. public static void main(String [] args) {
16. Forest f= new Forest();
17. try {
18. FileOutputStream fs = new FileOutputStream(”Forest.ser”);
19. ObjectOutputStream os = new ObjectOutputStream(fs);
20. os.writeObject(f); os.close();
21. } catch (Exception ex) { ex.printStackTrace(); }
22. } }
23.
24. class Tree { }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. An instance of Forest is serialized.
D. A instance of Forest and an instance of Tree are both serialized.Answer: B
Question 98
Click the Exhibit button.
1. import java.io.*;
2. public class Foo implements Serializable {
3. public int x, y;
4. public Foo( int x, int y) { this.x = x; this.y = y; }
5.
6. private void writeObject( ObjectOutputStream s)
7. throws IOException {
8. s.writeInt(x); s.writeInt(y)
9. }
10.
11. private void readObject( ObjectInputStream s)
12. throws IOException, ClassNotFoundException {
13.
14. // insert code here
15.
16. }
17. }
Which code, inserted at line 14, will allow this class to correctly
serialize and deserialize?
A. s.defaultReadObject();
B. this = s.defaultReadObject();
C. y = s.readInt(); x = s.readInt();
D. x = s.readInt(); y = s.readInt();
Answer: D
Question 99
Which three concerning the use of the java.io.Serializable interface are
true? (Choose three.)
A. Objects from classes that use aggregation cannot be serialized.
B. Art object serialized on one JVM can be successfully deserialized on
a different JVM.
C. The values in fields with the volatile modifier will NOT survive
serialization and deserialization.
D. The values in fields with the transient modifier will NOT survive
serialization and deserialization.
E. It is legal to serialize an object of a type that has a supertype that
does NOT implement java.io.Serializable.Answer: BDE
Question 100
Assuming that the serializeBanana() and the deserializeBanana()
methods will correctly use Java serialization and given:
13. import java.io.*;
14. class Food implemertts Serializable {int good = 3;}
15. class Fruit externds Food {int juice = 5;}
16. public class Banana extends Fruit {
17. int yellow = 4;
18. public static void main(String [] args) {
19. Banana b = new Banana(); Banana b2 = new Banana();
20. b.serializeBanana(b);
// assume correct serialization
21. b2 = b.deserializeBanana();
// assume correct
22. System.out.println(”restore “+b2.yellow+ b2.juice+b2.good);
24. }
25. // more Banana methods go here
50. }
‘What is the result?
A. restore 400
B. restore 403
C. restore 453
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: C
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