Oracle Advacned Java Advanced Certification Questions and Answers (Dumps and Practice Questions)
Question : You have been given below code, what is the expected behavior?
package com.hadoopexam;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class Welcome {
public static void main(String[] args) throws IOException {
BufferedReader bufferedReader = null;
try (BufferedReader _bufferedReader = new BufferedReader(new FileReader("resources\\Message.txt"))) { // line n1
_bufferedReader.lines().forEach(eachChar -> System.out.println(eachChar));
bufferedReader = _bufferedReader;// line n2
}
bufferedReader.ready(); // line n3;
}
}
1. A compilation error occurs at line n3.
2. A compilation error occurs at line n1.
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4. The code prints the content of the resources\\Message.txt file and throws an exception at line n3.
Correct Answer : Get Lastest Questions and Answer :
Explanation: As soon as we are out of block. Stream will be closed.
boolean java.io.BufferedReader.ready() throws IOException
Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.
Overrides: ready() in Reader
Returns:
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
Throws:
IOException - If an I/O error occurs
Question : You have been given below code, what is the behavior expected?
package com.hadoopexam;
public class Welcome {
private String startCourse(String bname) {
return "Watch " + bname;
}
}
class Child extends Welcome {
public String startCourse(String url) {
return "Complete " + url;
}
}
class Util {
public static void main(String[] args) {
Welcome p1 = new Welcome();
p1.startCourse("Hadoop Training"); //n1
Welcome child = new Child();
child.startCourse("http://hadoopexam.com/java"); //n2
}
}
1. Watch Hadoop Training
Complete http://hadoopexam.com/java
2. Watch Hadoop Training
Watch http://hadoopexam.com/java
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4. The Util.java file fails to compile.
Correct Answer : Get Lastest Questions and Answer :
Explanation: private method is not accessible in other classes. It will be accessible only in same class.
Question : Which of the following code snippet is correct?
1. class Welcome implements Callable {
public int call() {
System.out.println("In Callable.call()");
return 0;
}
}
2. class Welcome extends Callable {
public Integer call() {
System.out.println("In Callable.call()");
return 0;
}
}
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public Integer call() {
System.out.println("In Callable.call()");
return 0;
}
}
4. A and C
Correct Answer : Get Lastest Questions and Answer :
Explanation: Callable is interface, hence B cannot be correct. Call() methods can retrun Object not primitive type. Hence, option A is wrong.
V java.util.concurrent.Callable.call() throws Exception
Computes a result, or throws an exception if unable to do so.
Returns:
computed result
Throws:
Exception - if unable to compute a result
Related Questions
Question : You have been given below code, what is the expected behavior?
package com.hadoopexam;
import java.io.IOException;
public class Welcome extends Thread {
@Override
public void run() {
System.out.print("HadoopExam");
}
public static void main(String[] args) throws IOException, InterruptedException {
Welcome wel = new Welcome();
wel.start();
Thread.sleep(500);
System.out.print(".com ");
}
}
1. It will give compile time error
2. It will give run time error
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4. It will print "HadoopExam"
5. It will print "HadoopExam.com"
Question : You have a various runnable tasks, which needs to be executed one by one, based on their priority (Between to ). However, you are keep getting higher priority tasks
in the Queue and you lower priority tasks will never get an opportunity to being executed. Which of the following problem is discussed in above statement?
A. Deadlock
B. Starvation
C. Livelock
D. R ace condition
1. Deadlock
2. Starvation
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4. R ace condition
Question : Which of the following definition are correct?
1. class Welocme {
public synchronized void foo() {}
}
2. abstract class Welcome {
public abstract synchronized void foo();
}
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public synchronized void foo();
}
4. A and C
Question : You have been given below code, what is the expected behavior?
package com.hadoopexam;
import java.util.concurrent.atomic.AtomicInteger;
public class Welcome {
static AtomicInteger atomicInt = new AtomicInteger(100);
public static void plustOne() {
atomicInt.incrementAndGet();
}
public static void minusOne() {
atomicInt.getAndDecrement();
}
public static void setValue() {
atomicInt.compareAndSet(100, 99);
}
public static void main(String[] args) {
plustOne();
minusOne();
setValue();
System.out.println(atomicInt);
}
}
1. It will give compile time error.
2. It will print 100
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4. It will print 99
5. It will print "Null"
Question : You have been given below code, what is the output, when executed using command "java -ea RateOfInterest"
package com.hadoopexam;
public class Welcome {
public static void main(String[] args) {
int courseFee = 0;
String courseName = "Web Service";
switch (courseName) {
case "Hadoop":
courseFee = 79;
break;
case "Spark":
courseFee = 89;
break;
default:
assert false : "Given course is in Progress and currently not available"; // line n1
}
System.out.println("Fees for the course is :" + courseFee);
}
}
1. AssertionError: Given course is in Progress and currently not available
2. It will print Given course is in Progress and currently not available.
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4. A compilation error occurs at line n1.
Question :
You have been given below code, what is the behavior expected?
package com.hadoopexam;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class Welcome implements Callable
String message;
public Welcome(String s) {
this.message = s;
}
public String call() throws Exception {
return message.concat("Welcome to HadoopExam Learning Resources");
}
public static void main(String[] args) throws InterruptedException, ExecutionException {
ExecutorService executorService = Executors.newFixedThreadPool(4); // line n1
Future futureResult = executorService.submit(new Welcome("Thank you ... "));
String resultValue = futureResult.get().toString();
System.out.println(resultValue);
}
}
1. The program prints Thank you ... Welcome to HadoopExam Learning Resources and terminates.
2. The program prints Thank you ... Welcome to HadoopExam Learning Resources and does not terminate.
4. An ExecutionExceptionis thrown at run time.