2011年JAVA认证模拟题第二阶段（24）

会计考友

　　Q70.What kind of stream is the System.out object?
( t3 b( D  E, L　　a. java.io.BufferedWriter
　　b. java.io.PrintStream
" u; X0 m3 K/ n1 w; t" K" o2 a3 X　　c. java.io.FileWriter
　　d. java.io.OutputStreamWriter
　　Q71.Which of the following events has a matching adapter class that implements the appropriate listener interface? Select all correct answers.
　　a. java.awt.event.MouseEvent
　　b. java.awt.event.ActionEvent
* S4 O3 }, y1 \) ?　　c. java.awt.event.FocusEvent
　　d. java.awt.event.ItemEvent
) m! m% I# i7 ]　　Q72.Here is a partial listing of a class to represent a game board in a networked game. It is desired to prevent collisions due to more than one Thread using the addPic method to modify the array of Image references.
　　1. class Board extends Object {
　　2. Image[] pics = new Image[64];
3 D9 {7 D* u# l　　3. int active = 0;
　　4. public boolean addPic( Image mg, int pos) {
* l0 r' k% |5 z# c3 ]　　5. synchronized (this) {
　　6. if (pics[pos] == null)
　　7. { active++ ; pics[pos] = mg; return true; ｝
+ W& h  `+ i& f6 P6 \8 ]　　8. else
* Q% B+ E; I( u* m. k　　9. return false;
2 V& _3 \$ Y5 L" y8 X- V　　10. ｝
　　11. ｝
8 x) l6 h4 o- D1 G　　12. // remainder of class
　　Select all the alternatives for line 5 that would accomplish this.
　　a. synchronized (this)
3 }% ^+ V( _) z! E　　b. synchronized (pics)
  |0 T" P9 |8 q　　c. synchronized (mg)
　　d. synchronized (active)
! S; [/ m: e2 i1 Y) w( C1 U/ x! z　　70. b
　　71. ac
' R# }4 e, B' q　　72. ab