考题
10. class Foo { 11. static void alpha() { /* more code here */ } 12. void beta() { /* more code here */ } 13. } Which two are true?()A、 Foo.beta() is a valid invocation of beta().B、 Foo.alpha() is a valid invocation of alpha().C、 Method beta() can directly call method alpha().D、 Method alpha() can directly call method beta().
考题
Which two statements are true?()A、 An inner class may be declared as static.B、 An anonymous inner class can be declared as public.C、 An anonymous inner class can be declared as private.D、 An anonymous inner class can extend an abstract class.E、 An anonymous inner class can be declared as protected.
考题
package foo; public class Outer { public static class Inner { } } Which statement is true?() A、 Compilation fails.B、 An instance of the Inner class can be constructed with “new Outer.Inner()”.C、 An instance of the Inner class cannot be constructed outside of package foo.D、 An instance of the Inner class can be constructed only from within the Outer class.E、 From within the package foo, and instance of the Inner class can be constructed with “new Inner()”.
考题
public class SyncTest { private int x; private int y; private synchronized void setX( int i ) { x = i; } private synchronized void setY( int i ) { y = i; } public void setXY( int i ) { setX(i); setY(i); } public synchronized boolean check() { return x != y; } } Under which condition will check return true when called from a different class? () A、 check can never return true.B、 check can return true when setXY is called by multiple threads.C、 check can return true when multiple threads call setX and setY separately.D、 check can return true only if SyncTest is changed to allow x and y to be set separately.
考题
Which two of statements are true?()A、It is possible to synchronize static methods.B、When a thread has yielded as a result of yield(), it releases its locks.C、When a thread is sleeping as a result of sleep(), it releases its locks.D、The Object.wait() method can be invoked only from a synchronized context.E、The Thread.sleep() method can be invoked only from a synchronized context.F、When the thread scheduler receives a notify() request, and notifies a thread, that thread immediately releases its lock.
考题
public class SyncTest ( private int x; private int y; private synchronized void setX (int i) (x=1;) private synchronized void setY (int i) (y=1;) public void setXY(int 1)(set X(i); setY(i);) public synchronized Boolean check() (return x !=y;) ) Under which conditions will check () return true when called from a different class? A、 Check() can never return true.B、 Check() can return true when setXY is called by multiple threads.C、 Check() can return true when multiple threads call setX and setY separately.D、 Check() can only return true if SyncTest is changed to allow x and y to be setseparately.
考题
package foo; public class Outer ( public static class Inner ( ) ) Which statement is true? () A、 An instance of the Inner class can be constructed with “new Outer.Inner ()”B、 An instance of the inner class cannot be constructed outside of package foo.C、 An instance of the inner class can only be constructed from within the outer class.D、 From within the package bar, an instance of the inner class can be constructed with “new inner()”
考题
Which the following two statements are true?()A、 An inner class may be declared as static.B、 An anonymous inner class can be declared as public.C、 An anonymous inner class can be declared as private.D、 An anonymous inner class can extend an abstract class.E、 An anonymous inner class can be declared as protected.
考题
It is desirable that a certain method within a certain class can only be accessed by classes that are defined within the same package as the class of the method. How can such restrictions be enforced?() A、Mark the method with the keyword public.B、Mark the method with the keyword protected.C、Mark the method with the keyword private.D、Mark the method with the keyword package.E、Do not mark the method with any accessibility modifiers.
考题
Which statement is true?()A、 An anonymous inner class may be declared as final.B、 An anonymous inner class can be declared as private.C、 An anonymous inner class can implement multiple interfaces.D、 An anonymous inner class can access final variables in any enclosing scope.E、 Construction of an instance of a static inner class requires an instance of the enclosing outer class.
考题
Which will declare a method that is available to all members of the same package and can be referenced without an instance of the class?() A、 Abstract public void methoda();B、 Public abstract double methoda();C、 Static void methoda(double d1){}D、 Public native double methoda() {}E、 Protected void methoda(double d1) {}
考题
Which declaration prevents creating a subclass of an outer class?() A、 Static class FooBar{}B、 Private class FooBar{}C、 Abstract public class FooBar{}D、 Final public class FooBar{}E、 Final abstract class FooBar{}
考题
public class TestSeven extends Thread { private static int x; public synchronized void doThings() { int current = x; current++; x = current; } public void run() { doThings(); } } Which is true?() A、 Compilation fails.B、 An exception is thrown at runtime.C、 Synchronizing the run() method would make the class thread-safe.D、 The data in variable “x” are protected from concurrent access problems.E、 Declaring the doThings() method as static would make the class thread-safe.F、 Wrapping the statements within doThings() in a synchronized(new Object()) {} block would make the class thread-safe.
考题
Which two statements are true about using the isUserInRole method to implement security in a Java EEapplication?()A、It can be invoked only from the doGet or doPost methods.B、It can be used independently of the getRemoteUser method.C、Can return "true" even when its argument is NOT defined as a valid role name in the deployment descriptor.D、Using the isUserInRole method overrides any declarative authentication related to the method in which it is invoked.
考题
public class SyncTest { private int x; private int y; public synchronized void setX (int i) (x=1;) public synchronized void setY (int i) (y=1;) public synchronized void setXY(int 1)(set X(i); setY(i);) public synchronized Boolean check() (return x !=y;) } Under which conditions will check () return true when called from a different class?A、 Check() can never return true.B、 Check() can return true when setXY is called by multiple threads.C、 Check() can return true when multiple threads call setX and setY separately.D、 Check() can only return true if SyncTest is changed to allow x and y to be set separately.
考题
Which three statements are true?()A、A final method in class X can be abstract if and only if X is abstract.B、A protected method in class X can be overridden by any subclass of X.C、A private static method can be called only within other static methods in class X.D、A non-static public final method in class X can be overridden in any subclass of X.E、A public static method in class X can be called by a subclass of X without explicitly referencing the class X.F、A method with the same signature as a private final method in class X can be implemented in a subclass of X.G、A protected method in class X can be overridden by a subclass of X only if the subclass is in the same package as X.
考题
Which two statements are true about the hashCode method?()A、The hashCode method for a given class can be used to test for object equality and object inequality for that class.B、The hashCode method is used by the java.util.SortedSet collection class to order the elements within that set.C、The hashCode method for a given class can be used to test for object inequality, but NOT objecte quality, for that class.D、The only important characteristic of the values returned by a hashCode method is that the distribution of values must follow a Gaussian distribution.E、The hashCode method is used by the java.util.HashSet collection class to group the elements within that set into hash buckets for swift retrieval.
考题
单选题package foo; public class Outer { public static class Inner { } } Which statement is true?()A
Compilation fails.B
An instance of the Inner class can be constructed with “new Outer.Inner()”.C
An instance of the Inner class cannot be constructed outside of package foo.D
An instance of the Inner class can be constructed only from within the Outer class.E
From within the package foo, and instance of the Inner class can be constructed with “new Inner()”.
考题
单选题Which statement is true?()A
An anonymous inner class may be declared as final.B
An anonymous inner class can be declared as private.C
An anonymous inner class can implement multiple interfaces.D
An anonymous inner class can access final variables in any enclosing scope.E
Construction of an instance of a static inner class requires an instance of the enclosing outer class.
考题
单选题It is desirable that a certain method within a certain class can only be accessed by classes that are defined within the same package as the class of the method. How can such restrictions be enforced?()A
Mark the method with the keyword public.B
Mark the method with the keyword protected.C
Mark the method with the keyword private.D
Mark the method with the keyword package.E
Do not mark the method with any accessibility modifiers.
考题
多选题Which two of statements are true?()AIt is possible to synchronize static methods.BWhen a thread has yielded as a result of yield(), it releases its locks.CWhen a thread is sleeping as a result of sleep(), it releases its locks.DThe Object.wait() method can be invoked only from a synchronized context.EThe Thread.sleep() method can be invoked only from a synchronized context.FWhen the thread scheduler receives a notify() request, and notifies a thread, that thread immediately releases its lock.
考题
多选题Which two statements are true?()AAn inner class may be declared as static.BAn anonymous inner class can be declared as public.CAn anonymous inner class can be declared as private.DAn anonymous inner class can extend an abstract class.EAn anonymous inner class can be declared as protected.
考题
多选题Which two statements are true about the hashCode method?()AThe hashCode method for a given class can be used to test for object equality and object inequality for that class.BThe hashCode method is used by the java.util.SortedSet collection class to order the elements within that set.CThe hashCode method for a given class can be used to test for object inequality, but NOT objecte quality, for that class.DThe only important characteristic of the values returned by a hashCode method is that the distribution of values must follow a Gaussian distribution.EThe hashCode method is used by the java.util.HashSet collection class to group the elements within that set into hash buckets for swift retrieval.
考题
单选题Which declaration prevents creating a subclass of an outer class?()A
Static class FooBar{}B
Private class FooBar{}C
Abstract public class FooBar{}D
Final public class FooBar{}E
Final abstract class FooBar{}
考题
多选题Which the following two statements are true?()AAn inner class may be declared as static.BAn anonymous inner class can be declared as public.CAn anonymous inner class can be declared as private.DAn anonymous inner class can extend an abstract class.EAn anonymous inner class can be declared as protected.
考题
单选题Which will declare a method that is available to all members of the same package and can be referenced without an instance of the class?()A
Abstract public void methoda();B
Public abstract double methoda();C
Static void methoda(double d1){}D
Public native double methoda(){}E
Protected void methoda(double d1){}
考题
多选题Which two statements are true about using the isUserInRole method to implement security in a Java EEapplication?()AIt can be invoked only from the doGet or doPost methods.BIt can be used independently of the getRemoteUser method.CCan return true even when its argument is NOT defined as a valid role name in the deployment descriptor.DUsing the isUserInRole method overrides any declarative authentication related to the method in which it is invoked.