单项选择题
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();
相关考题
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单项选择题
import java.io.*; public class Forest implements Serializable { private Tree tree = new Tree(); public static void main(String [] args) { Forest f= new Forest(); try { FileOutputStream fs = new FileOutputStream(”Forest.ser”); ObjectOutputStream os = new ObjectOutputStream(fs); os.writeObject(f); os.close(); } catch (Exception ex) { ex.printStackTrace(); } } } 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. -
单项选择题
Whencomparingjava.io.BufferedWritertojava.io.FileWriter,whichcapabilityexistsasamethodinonlyoneofthetwo?()
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 -
多项选择题
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?()
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.
