更多"public class Threads4&ens"的相关试题:
[多项选择] public class SyncTest{ public static void main(String args) { final StringBuffer s1= new StringBuffer(); final StringBuffer s2= new StringBuffer(); new Thread () { public void run() { synchronized(s1) { s2.append(“A”); synchronized(s2) { s2.append(“B”); System.out.print(s1); System.out.print(s2); } } } }.start(); new Thread() { public void run() { synchronized(s2) { s2.append(“C”); synchronized(s1) { s1.append(“D”); System.out.print(s2); System.out.print(s1); } } } }.start(); } } Which two statements are true? ()
A. The program prints “ABBCAD”
B. The program prints “CDDACB”
C. The program prints “ADCBADBC”
D. The output is a non-deterministic point because of a possible deadlock condition.
E. The output is dependent on the threading model of the system the program is running on.
[单项选择] public class Mycircle { public double radius; public double diameter; public void setRadius(double radius) this.radius = radius; this.diameter= radius * 2; } public double getRadius() { return radius; } Which statement is true?()
A. The Mycircle class is fully encapsulated.
B. The diameter of a given MyCircle is guaranteed to be twice its radius.
C. Lines 6 and 7 should be in a synchronized block to ensure encapsulation.
D. The radius of a MyCircle object can be set without affecting its diameter.
[单项选择] public class WhileFoo { public static void main (String []args) { int x= 1, y = 6; while (y--) {x--;} system.out.printIn(“x=” + x “y =” + y); } } What is the result?()
A. The output is x = 6 y = 0
B. The output is x = 7 y = 0
C. The output is x = 6 y = -1
D. The output is x = 7 y = -1
E. Compilation will fail.
[单项选择] public class Threads5 { public static void main (String[] args) { new Thread(new Runnable() { public void run() { System.out.print(”bar”); } }).start(); } } What is the result?()
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes normally and prints “bar”.
D. The code executes normally, but nothing prints.
[多项选择] 1. class Calc { 2. public static void main(String [] args) { 3. try { 4. int x = Integer.parseInt("42a"); 5. //insert code here 6. System.out.print("oops "); 7. } 8. } 9. } 下面哪两行分别插入到第五行,会导致输出“oops”?()
A. } catch (ClassCastException c) {
B. } catch (IllegalStateException c) {
C. } catch (NumberFormatException n) {
D. } catch (IllegalArgumentException e) {
[单项选择] import java.io.IOException; public class ExceptionTest( public static void main (Stringargs) try ( methodA(); ) catch (IOException e) ( system.out.printIn(“Caught IOException”); ) catch (Exception e) ( system.out.printIn(“Caught Exception”); ) ) public void methodA () { throw new IOException (); } What is the result?()
A. The code will not compile.
B. The output is caught exception.
C. The output is caught IOException.
D. The program executes normally without printing a message.
[单项选择] 1.public class test ( 2.public static void main (String args[]) { 3.int i = 0xFFFFFFF1; 4.int j = ~i; 5. 6.} 7.) What is the decimal value of j at line 5?()
A. 0
B. 1
C. 14
D. –15
E. An error at line 3 causes compilation to fail.
F. An error at line 4 causes compilation to fail.
[单项选择] 1.public class Test { 2.public static void main (String args[]) { 3.class Foo { 4.public int i = 3; 5.} 6.Object o = (Object) new Foo(); 7.Foo foo = (Foo)o; 8.System.out.printIn(foo. i); 9. } 10.} What is the result?()
A. Compilation will fail.
B. Compilation will succeed and the program will print “3”
C. Compilation will succeed but the program will throw a ClassCastException at line 6.
D. Compilation will succeed but the program will throw a ClassCastException at line 7.
[单项选择] 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();
[多项选择]
下列解释正确的是()
A. out_applet.java中一定有一个参数是“display_string”
B.
具有两个属性“name”和“value”
C. value是参数的名称
D. “good morning”通过
标记传递给“Our_Applet.class”
[简答题] 一般程序如下: ORG 2000H ARY DW --4,3,--2,1 CNT DW $--ARY VAR DW ARY,$+4 ┆ MOV AX,ARY MOV BX,OFFSET VAR MOV CX,CNT MOV DX,VAR+2 LEA SI,ARY ┆ 此程序段执行后,寄存器AX,BX,CX,DX与SI中的内容各是多少?
[单项选择] 现有: 1 Interface F{} 2 class A implements F{} 3 class B extends A{} 4 class C extends B{ 5 public static void main(String[] args){ 6 B b=new B(); 7 //inSert C0de here 8 } 9 } 下列哪行代码插入到第7行,将抛出java.lang.ClassCaseException异常()
A. A a=b;
B. F f= (C)b;
C. F f= (A)b;
D. B bb= (B)(A)b;
[单项选择] 现有: class Pencil { public void write (String content){ System.out.println ("Write"+content); } } class RubberPencil extends Pencil{ public void erase (String content){ System.out.println ("Erase"+content); } } 执行下列代码的结果是哪项?() Pencil pen=new RubberPencil(); pen.write ("Hello"); pen.erase ("Hello");
A. Write Hello Erase Hello
B. Erase Hello Write Hello
C. 编译错误
D. 运行时抛出异常
[多项选择] public class Foo { private int val; public foo(int v) (val = v;) } public static void main (String args) { Foo a = new Foo (10); Foo b = new Foo (10); Foo c = a; int d = 10; double e = 10.0; } Which three logical expression evaluate to true? ()
A. (a ==c)
B. (d ==e)
C. (b ==d)
D. (a ==b)
E. (b ==c)
F. (d ==10.0)
[单项选择] public class Pet{ private String name; public Pet(){ System.out.print(1); } public Pet(String name){ System.out.print(2); } } public class Dog extends Pet{ public Dog(String name){ System.out.print(3); } } 执行new Dog(“棕熊”);后程序输出是哪项?()
A. 23
B. 13
C. 123
D. 321
[单项选择] 现有 public class Parentt public void change (int x){) ) public class Child extends Parent{ //覆盖父类change方法 } 下列哪个声明是正确的覆盖了父类的change方法?()
A. protected void change (int x){}
B. public void change(int x, int y){}
C. public void change (int x){}
D. public void change (String s){}