Given the code fragment:
class CallerThread implements Callable<String> {
String str;
public CallerThread(String s) {this.str=s;}
public String call() throws Exception {
return str.concat("Call");
}
}
and
public static void main (String[] args) throws InterruptedException, ExecutionException
{
ExecutorService es = Executors.newFixedThreadPool(4); //line n1
Future f1 = es.submit (newCallerThread("Call"));
String str = f1.get().toString();
System.out.println(str);
}
Which statement is true?

Given:

From what threading problem does the program suffer?

Given the code fragment:
Path source = Paths.get ("/data/december/log.txt");
Path destination = Paths.get("/data");
Files.copy (source, destination);
and assuming that the file /data/december/log.txt is accessible and
contains:
10-Dec-2014 ?Executed successfully
What is the result?

Given the code fragments:
class Employee {
Optional<Address> address;
Employee (Optional<Address> address) {
this.address = address;
}
public Optional<Address> getAddress() { return address; }
}
class Address {
String city = "New York";
public String getCity { return city: }
public String toString() {
return city;
}
}
and
Address address = null;
Optional<Address> addrs1 = Optional.ofNullable (address);
Employee e1 = new Employee (addrs1);
String eAddress = (addrs1.isPresent()) ? addrs1.get().getCity() : "City Not
available";
What is the result?

Given the code fragment:
ZonedDateTime depart = ZonedDateTime.of(2015, 1, 15, 3, 0, 0, 0, ZoneID.of ( "UTC-7"));
ZonedDateTime arrive = ZonedDateTime.of(2015, 1, 15, 9, 0, 0, 0, ZoneID.of ( "UTC-5"));
long hrs = ChronoUnit.HOURS.between(depart, arrive); //line n1
System.out.println("Travel time is" + hrs + "hours");
What is the result?