Free Oracle 1z1-830 Exam Dumps Questions & Answers

Given:
java
try (FileOutputStream fos = new FileOutputStream("t.tmp");
ObjectOutputStream oos = new ObjectOutputStream(fos)) {
fos.write("Today");
fos.writeObject("Today");
oos.write("Today");
oos.writeObject("Today");
} catch (Exception ex) {
// handle exception
}
Which statement compiles?

• A.oos.write("Today");
• B.fos.writeObject("Today");
• C.fos.write("Today");
• D.oos.writeObject("Today");

Which of the following statements is correct about a final class?

• A.It cannot extend another class.
• B.The final keyword in its declaration must go right before the class keyword.
• C.It cannot be extended by any other class.
• D.It cannot implement any interface.
• E.It must contain at least a final method.

Given:
java
var array1 = new String[]{ "foo", "bar", "buz" };
var array2[] = { "foo", "bar", "buz" };
var array3 = new String[3] { "foo", "bar", "buz" };
var array4 = { "foo", "bar", "buz" };
String array5[] = new String[]{ "foo", "bar", "buz" };
Which arrays compile? (Select 2)

• A.array5
• B.array2
• C.array4
• D.array3
• E.array1

Given:
java
import java.io.*;
class A implements Serializable {
int number = 1;
}
class B implements Serializable {
int number = 2;
}
public class Test {
public static void main(String[] args) throws Exception {
File file = new File("o.ser");
A a = new A();
var oos = new ObjectOutputStream(new FileOutputStream(file));
oos.writeObject(a);
oos.close();
var ois = new ObjectInputStream(new FileInputStream(file));
B b = (B) ois.readObject();
ois.close();
System.out.println(b.number);
}
}
What is the given program's output?

• A.ClassCastException
• B.1
• C.NotSerializableException
• D.2
• E.Compilation fails

Given:
java
Runnable task1 = () -> System.out.println("Executing Task-1");
Callable<String> task2 = () -> {
System.out.println("Executing Task-2");
return "Task-2 Finish.";
};
ExecutorService execService = Executors.newCachedThreadPool();
// INSERT CODE HERE
execService.awaitTermination(3, TimeUnit.SECONDS);
execService.shutdownNow();
Which of the following statements, inserted in the code above, printsboth:
"Executing Task-2" and "Executing Task-1"?

• A.execService.call(task2);
• B.execService.submit(task2);
• C.execService.execute(task1);
• D.execService.execute(task2);
• E.execService.run(task2);
• F.execService.call(task1);
• G.execService.run(task1);
• H.execService.submit(task1);