Oracle 1Z0-850 問題集

質問 1：
Which two are advantages of using J2EE server-side technologies in a web-based application? (Choose two.)
A. complexity
B. scalability
C. monolithic design
D. network latency
E. separation of concerns
正解：B,E

質問 2：
You are asked to create code that defines a Beverage, and includes method implementation code for some beverage behaviors. Beverage subtypes will be required to provide implementations of some, but not all, of the methods defined in Beverage.
Which approach correctly implements these goals?
A. Create a concrete Beverage class that defines both abstract and concrete methods.
B. Create an abstract Beverage class that defines only abstract methods.
C. Create a Beverage interface that all beverage subtypes must implement.
D. Create an abstract Beverage class that defines both abstract and concrete methods.
正解：D

質問 3：
Given:
1 . class Test {
2 . public static void main(String args[]) {
3 . String str = "Hello!";
4 . String str2 = "Bye!";
5 . str += str2;
6 . str -= str2;
7 .
8 . if ( str == str2 ) {
9 . System.out.println("str = str2");
1 0. } else {
1 1. System.out.println("str != str2");
1 2. }
1 3. }
1 4. }
What is the result?
A. str != str2
B. The code runs with no output.
C. str = str2
D. Compilation fails.
正解：D

質問 4：
Which is an advantage of applets over HTML/JavaScript clients?
A. Applets are downloaded more quickly to the client.
B. Applets can use a wider variety of UI components.
C. Applets are more widely supported by browsers.
D. In their default state, applets have access to the client's computer.
正解：B

質問 5：
A business-tier service is being developed that will provide credit card validation. The service is not associated with a specific client, but is available to all clients. The service also has to be as efficient as possible. Which J2EE component matches these needs?
A. stateless session bean
B. stateful session bean
C. servlet
D. JNDI
E. entity bean
正解：A

質問 6：
Given:
1 . public abstract class Wow {
2 . private int wow;
3 . public Wow(int wow) {
4 . this.wow = wow;
5 . }
6 . public void wow() { }
7 . private void wowza() { }
8 . }
Which is true about the class Wow?
A. It does NOT compile because an abstract class CANNOT have private methods.
B. It compiles without error.
C. It does NOT compile because an abstract class must have at least one abstract method.
D. It does NOT compile because an abstract class CANNOT have instance variables.
E. It does NOT compile because an abstract class must have a constructor with no arguments.
正解：B

質問 7：
Given:
17. class B { }
Which demonstrates inheritance?
A. class A super B { }
B. class A extends B { }
C. class A implements B { }
D. class A this B { }
正解：B