Given the code fragments:
class MyThread implements Runnable {
private static AtomicInteger count = new AtomicInteger (0);
public void run () {
int x = count.incrementAndGet();
System.out.print (x+" ");
}
}
and
Thread thread1 = new Thread(new MyThread());
Thread thread2 = new Thread(new MyThread());
Thread thread3 = new Thread(new MyThread());
Thread [] ta = {thread1, thread2, thread3};
for (int x= 0; x < 3; x++) {
ta[x].start();
}
Which statement is true?
A. The program prints 1 2 3 and the order is unpredictable.
B. The program prints 1 2 3.
C. The program prints 1 1 1.
D. A compilation error occurs.
Given the code fragment:
List
System.out.println (
// line n1
);
Which code fragment, when inserted at line n1, enables the code to print the count of string elements
whose length is greater than three?
A. listVal.stream().filter(x -> x.length()>3).count()
B. listVal.stream().map(x -> x.length()>3).count()
C. listVal.stream().peek(x -> x.length()>3).count().get()
D. listVal.stream().filter(x -> x.length()>3).mapToInt(x -> x).count()
Given:
public class Customer {
private String fName;
private String lName;
private static int count;
public customer (String first, String last) {fName = first, lName = last;
++count;}
static { count = 0; }
public static int getCount() {return count; }
}
public class App {
public static void main (String [] args) {
Customer c1 = new Customer("Larry", "Smith");
Customer c2 = new Customer("Pedro", "Gonzales");
Customer c3 = new Customer("Penny", "Jones");
Customer c4 = new Customer("Lars", "Svenson");
c4 = null;
c3 = c2;
System.out.println (Customer.getCount());
}
}
What is the result?
A. 0
B. 2
C. 3
D. 4
E. 5
Which two code blocks correctly initialize a Locale variable? (Choose two.)
A. Locale loc1 = "UK";
B. Locale loc2 = Locale.getInstance("ru");
C. Locale loc3 = Locale.getLocaleFactory("RU");
D. Locale loc4 = Locale.UK;
E. Locale loc5 = new Locale ("ru", "RU");
Given:
class RateOfInterest {
public static void main (String[] args) {
int rateOfInterest = 0;
String accountType = "LOAN";
switch (accountType) {
case "RD";
rateOfInterest = 5;
break;
case "FD";
rateOfInterest = 10;
break;
default: assert false: "No interest for this account"; //line n1 } System.out.println ("Rate of interest:" + rateOfInterest); } }
and the command:
java -ea RateOfInterest
What is the result?
A. Rate of interest: 0
B. An AssertionError is thrown.
C. No interest for this account
D. A compilation error occurs at line n1.
Given the code fragment:
class CallerThread implements Callable
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?
A. The program prints Call Call and terminates.
B. The program prints Call Call and does not terminate.
C. A compilation error occurs at line n1.
D. An ExecutionException is thrown at run time.
Given the code fragment:
What is the result?
A. A compilation error occurs at line n1.
B. Logged out at: 2015-01-12T21:58:19.880Z
C. Can't logout
D. Logged out at: 2015-01-12T21:58:00Z
Given the code fragment:
What is the result?
A. A compilation error occurs at line n1.
B. Checking...
C. Checking... Checking...
D. A compilation error occurs at line n2.
Assume customers.txt is accessible and contains multiple lines.
Which code fragment prints the contents of the customers.txt file?
A. Stream
B. Stream
C. Stream
D. Stream
Given:
and the code fragment:
What is the result?
A. An exception is thrown at line n2.
B. 100
C. A compilation error occurs because the try block is declared without a catch or finally block.
D. A compilation error occurs at line n1.
Given the Greetings.properties file, containing:
and given:
What is the result?
A. Compilation fails.
B. GOODBY_MSG
C. Hello, everyone!
D. Goodbye everyone!
E. HELLO_MSG
Which two statements are true about synchronization and locks? (Choose two.)
A. A thread automatically acquires the intrinsic lock on a synchronized statement when executed.
B. The intrinsic lock will be retained by a thread if return from a synchronized method is caused by an uncaught exception.
C. A thread exclusively owns the intrinsic lock of an object between the time it acquires the lock and the time it releases it.
D. A thread automatically acquires the intrinsic lock on a synchronized method's object when entering that method.
E. Threads cannot acquire intrinsic locks on classes.
Given:
class Student {
String course, name, city;
public Student (String name, String course, String city) {
this.course = course; this.name = name; this.city = city;
}
public String toString() {
return course + ":" + name + ":" + city;
}
public String getCourse() {return course;}
public String getName() {return name;}
public String getCity() {return city;}
and the code fragment:
List
new Student ("Jessy", "Java ME", "Chicago"),
new Student ("Helen", "Java EE", "Houston"),
new Student ("Mark", "Java ME", "Chicago"));
stds.stream()
.collect(Collectors.groupingBy(Student::getCourse))
.forEach(src, res) -> System.out.println(scr));
What is the result?
A. A compilation error occurs.
B. Java EE Java ME
C. [Java EE: Helen:Houston] [Java ME: Jessy:Chicago, Java ME: Mark:Chicago]
D. [Java ME: Jessy:Chicago, Java ME: Mark:Chicago] [Java EE: Helen:Houston]
Given:
public class Counter {
public static void main (String[ ] args) {
int a = 10;
int b = -1;
assert (b >=1) : "Invalid Denominator";
int = a / b;
System.out.println (c);
}
}
What is the result of running the code with the 璬a option?
A. -10
B. 0
C. An AssertionError is thrown.
D. A compilation error occurs.
Given the code fragment:
Path path1 = Paths.get("/app/./sys/");
Path res1 = path1.resolve("log");
Path path2 = Paths.get("/server/exe/");
Path res1 = path2.resolve("/readme/");
System.out.println(res1);
System.out.println(res2);
What is the result?
A. /app/sys/log /readme/server/exe
B. /app/log/sys /server/exe/readme
C. /app/./sys/log /readme
D. /app/./sys/log /server/exe/readme