KillTest 质量更高 服务更好 学习资料 http://www.killtest.cn 半年免费更新服务
Exam : 1Z0-854 Title : Java Standard Edition 5 Programmer Certified Professional Upgrade Exam Version : Demo 1 / 12
1.Given: 20. public class CreditCard { 21. 22. private String cardid; 23. private Integer limit; 24. public String ownername; 25. 26. public void setcardinformation(string cardid, 27. String ownername, 28. Integer limit) { 29. this.cardid = cardid; 30. this.ownername = ownername; 31. this.limit = limit; 32. } 33. } Which statement is true? A. The ownername variable breaks encapsulation. B. The class is fully encapsulated. C. The cardid and limit variables break polymorphism. D. The code demonstrates polymorphism. E. The setcardinformation method breaks encapsulation. Answer: A 2.DRAG DROP Click the Task button.? Answer: 2 / 12
3.DRAG DROP Click the Task button. Answer: 3 / 12
4.Which three statements concerning the use of the java.io.serializable interface are true? (Choose three.) A. Objects from classes that use aggregation cannot be serialized. B. The values in fields with the transient modifier will NOT survive serialization and deserialization. C. It is legal to serialize an object of a type that has a supertype that does NOT implement java.io.serializable. D. The values in fields with the volatile modifier will NOT survive serialization and deserialization. E. An object serialized on one JVM can be successfully deserialized on a different JVM. Answer: B,C,E 5.Which two code fragments will execute the method dostuff() in a separate thread? (Choose two.) A. new Thread() { public void start() { dostuff(); }}; B. new Thread() { public void run() { dostuff(); }}; C. new Thread(new Runnable() { public void run() { dostuff(); } }).start(); D. new Thread() { public void start() { dostuff(); } }.run(); E. new Thread(new Runnable() { public void run() { dostuff(); } }).run(); F. new Thread() { 4 / 12
public void run() { dostuff(); } }.start(); Answer: C,F 6.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. An exception is thrown at runtime. B. An instance of Forest is serialized. C. An instance of Forest and an instance of Tree are both serialized. D. Compilation fails. Answer: A 7.Given: 1. interface TestA { String tostring(); } 2. public class Test { 3. public static void main(string[] args) { 4. System.out.println(new TestA() { 5. public String tostring() { return "test"; } 6. }); 7. } 8. } What is the result? A. null B. An exception is thrown at runtime. C. Compilation fails because of an error in line 5. D. Compilation fails because of an error in line 4. E. Compilation fails because of an error in line 1. F. test Answer: F 8.DRAG DROP 5 / 12
Click the Task button. Answer: 9.Given: 1. public class Boxer1{ 2. Integer i; 3. int x; 4. public Boxer1(int y) { 6 / 12
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. Compilation fails because of an error in line 5. B. A NullPointerException occurs at runtime. C. Compilation fails because of an error in line 9. D. A NumberFormatException occurs at runtime. E. The value "4" is printed at the command line. F. An IllegalStateException occurs at runtime. Answer: B 10.Given: 10: public class Hello { 11: String title; 12: int value; 13: public Hello() { 14: title += " World"; 15: } 16: public Hello(int value) { 17: this.value = value; 18: title = "Hello"; 19: Hello(); 20: } 21: } and: 30: Hello c = new Hello(5); 31: System.out.println(c.title); What is the result? A. The code runs with no output. B. Hello C. Hello World 5 D. Compilation fails. E. An exception is thrown at runtime. F. Hello World Answer: D 11.Given: 10. class Line { 11. public class Point { public int x,y;} 7 / 12
12. public Point getpoint() { return new Point(); } 13. } 14. class Triangle { 15. public Triangle() { 16. // insert code here 17. } 18. } Which code, inserted at line 16, correctly retrieves a local instance of a Point object? A. Point p = (new Line()).getPoint(); B. Line.Point p = Line.getPoint(); C. Point p = Line.getPoint(); D. Line.Point p = (new Line()).getPoint(); Answer: D 12.Given: 11. // insert code here 12. private N min, max; 13. public N getmin() { return min; } 14. public N getmax() { return max; } 15. public void add(n added) { 16. if (min == null added.doublevalue() < min.doublevalue()) 17. min = added; 18. if (max == null added.doublevalue() > max.doublevalue()) 19. max = added; 20. } 21. } Which two, inserted at line 11, will allow the code to compile? (Choose two.) A. public class MinMax<?> { B. public class MinMax<N extends Object> { C. public class MinMax<N extends Integer> { D. public class MinMax<? extends Object> { E. public class MinMax<N extends Number> { F. public class MinMax<? extends Number> { Answer: C,E 13.A developer is creating a class Book, that needs to access class Paper. The Paper class is deployed in a JAR named mylib.jar. Which three, taken independently, will allow the developer to use the Paper class while compiling the Book class? (Choose three.) A. The JAR file is located at $JAVA_HOME/jre/classes/myLib.jar. B. The JAR file is located at /foo/mylib.jar and the Book class is compiled using javac -d /foo/mylib.jar Book.java C. The JAR file is located at /foo/mylib.jar and a classpath environment variable is set that includes /foo/mylib.jar/paper.class. 8 / 12
D. The JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar.. E. The JAR file is located at /foo/mylib.jar and the Book class is compiled using javac -classpath /foo/mylib.jar Book.java F. The JAR file is located at /foo/mylib.jar and the Book class is compiled using javac -cp /foo/mylib.jar/paper Book.java. G. The JAR file is located at /foo/mylib.jar and a classpath environment variable is set that includes /foo/mylib.jar. Answer: D,E,G 14.Given: 10. public class SuperCalc { 11. protected static int multiply(int a, int b) { return a * b;} 12. } and: 20. public class SubCalc extends SuperCalc{ 21. public static int multiply(int a, int b) { 22. int c = super.multiply(a, b); 23. return c; 24. } 25. } and: 30. SubCalc sc = new SubCalc (); 31. System.out.println(sc.multiply(3,4)); 32. System.out.println(SubCalc.multiply(2,2)); What is the result? A. Compilation fails because of an error in line 31. B. The code runs with no output. C. 12 D. Compilation fails because of an error in line 22. E. An exception is thrown at runtime. F. Compilation fails because of an error in line 21. Answer: D 15.Given: 12. NumberFormat nf = NumberFormat.getInstance(); 13. nf.setmaximumfractiondigits(4); 14. nf.setminimumfractiondigits(2); 15. String a = nf.format(3.1415926); 16. String b = nf.format(2); Which two statements are true about the result if the default locale is Locale.US? (Choose two.) A. The value of a is 3.1415. B. The value of a is 3.14. C. The value of a is 3.141. D. The value of b is 2. 9 / 12
E. The value of b is 2.0000. F. The value of a is 3.1416. G. The value of b is 2.00. Answer: F,G 16.Click the Exhibit button. Which statement is true about the two classes? A. Compilation of class B will fail. Compilation of class A will succeed. B. Compilation of class A will fail. Compilation of class B will succeed. C. Compilation of both classes will fail. D. Compilation of both classes will succeed. Answer: A 17.Given: 11. class ClassA {} 12. class ClassB extends ClassA {} 13. class ClassC extends ClassA {} and: 21. ClassA p0 = new ClassA(); 22. ClassB p1 = new ClassB(); 23. ClassC p2 = new ClassC(); 24. ClassA p3 = new ClassB(); 25. ClassA p4 = new ClassC(); Which three are valid? (Choose three.) A. p2 = p4; B. p2 = (ClassC)p1; C. p0 = p1; D. p2 = (ClassC)p4; E. p1 = p2; F. p1 = (ClassB)p3; Answer: C,D,F 18.Given this method in a class: 10 / 12
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 statement is true? A. This code will perform well and converting the code to use StringBuilder will not enhance the performance. B. This code will perform poorly. For better performance, the code should be rewritten: return "<" + this.name + ">"; C. This code is NOT thread-safe. D. The programmer can replace StringBuffer with StringBuilder with no other changes. Answer: D 19.DRAG DROP Click the Task button. Answer: 11 / 12
20.Click the Exhibit button. What two must the programmer do to correct the compilation errors? (Choose two.) A. change the wheelcount variable in Car to protected B. insert a call to this() in the MeGo constructor C. insert a call to this() in the Car constructor D. insert a call to super(vin) in the MeGo constructor E. insert a call to super() in the MeGo constructor F. change line 3 in the MeGo class to super.wheelcount = 3; Answer: A,D 12 / 12