問題1
Given:
Which option fails?
Given:
Which option fails?
正確答案: B
問題2
Given:
and the code fragment:
What is the result?
Given:
and the code fragment:
What is the result?
正確答案: C
問題3
Given:
Which is refactored code with functional interfaces?
Given:
Which is refactored code with functional interfaces?
正確答案: A
問題4
Given:
and the code fragment:
What is the result?
Given:
and the code fragment:
What is the result?
正確答案: D
問題5
Given:
class Worker extends Thread {
CyclicBarrier cb;
public Worker(CyclicBarrier cb) { this.cb = cb; }
public void run () {
try {
cb.await();
System.out.println("Worker...");
} catch (Exception ex) { }
}
}
class Master implements Runnable { //line n1
public void run () {
System.out.println("Master...");
}
}
and the code fragment:
Master master = new Master();
//line n2
Worker worker = new Worker(cb);
worker.start();
You have been asked to ensure that the run methods of both the Worker and Master classes are executed.
Which modification meets the requirement?
Given:
class Worker extends Thread {
CyclicBarrier cb;
public Worker(CyclicBarrier cb) { this.cb = cb; }
public void run () {
try {
cb.await();
System.out.println("Worker...");
} catch (Exception ex) { }
}
}
class Master implements Runnable { //line n1
public void run () {
System.out.println("Master...");
}
}
and the code fragment:
Master master = new Master();
//line n2
Worker worker = new Worker(cb);
worker.start();
You have been asked to ensure that the run methods of both the Worker and Master classes are executed.
Which modification meets the requirement?
正確答案: C
問題6
Given the code fragment:
Path path1 = Paths.get("/app/./sys/");
Path res1 = path1.resolve("log");
Path path2 = Paths.get("/server/exe/");
Path res1 = path1.resolve("/readme/");
System.out.println(res1);
System.out.println(res2);
What is the result?
Given the code fragment:
Path path1 = Paths.get("/app/./sys/");
Path res1 = path1.resolve("log");
Path path2 = Paths.get("/server/exe/");
Path res1 = path1.resolve("/readme/");
System.out.println(res1);
System.out.println(res2);
What is the result?
正確答案: A
問題7
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?
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?
正確答案: B
問題8
Which statement is true about the single abstract method of the java.util.function.Function interface?
Which statement is true about the single abstract method of the java.util.function.Function interface?
正確答案: B
問題9
Given the definition of the Country class:
public class country {
public enum Continent {ASIA, EUROPE}
String name;
Continent region;
public Country (String na, Continent reg) {
name = na, region = reg;
}
public String getName () {return name;}
public Continent getRegion () {return region;}
}
and the code fragment:
List<Country> couList = Arrays.asList (
new Country ("Japan", Country.Continent.ASIA),
new Country ("Italy", Country.Continent.EUROPE),
new Country ("Germany", Country.Continent.EUROPE));
Map<Country.Continent, List<String>> regionNames = couList.stream ()
.collect(Collectors.groupingBy (Country ::getRegion,
Collectors.mapping(Country::getName, Collectors.toList()))));
System.out.println(regionNames);
What is the output?
Given the definition of the Country class:
public class country {
public enum Continent {ASIA, EUROPE}
String name;
Continent region;
public Country (String na, Continent reg) {
name = na, region = reg;
}
public String getName () {return name;}
public Continent getRegion () {return region;}
}
and the code fragment:
List<Country> couList = Arrays.asList (
new Country ("Japan", Country.Continent.ASIA),
new Country ("Italy", Country.Continent.EUROPE),
new Country ("Germany", Country.Continent.EUROPE));
Map<Country.Continent, List<String>> regionNames = couList.stream ()
.collect(Collectors.groupingBy (Country ::getRegion,
Collectors.mapping(Country::getName, Collectors.toList()))));
System.out.println(regionNames);
What is the output?
正確答案: D
問題10
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<Student> stds = Arrays.asList(
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(res));
What is the result?
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<Student> stds = Arrays.asList(
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(res));
What is the result?
正確答案: D
問題11
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?
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?
正確答案: D
問題12
Given:
and the code fragment:
What is the result?
Given:
and the code fragment:
What is the result?
正確答案: C
說明：（僅 NewDumps 成員可見）
問題13
Given the code fragments:
class Caller implements Callable<String> {
String str;
public Caller (String s) {this.str=s;}
public String call()throws Exception { return str.concat ("Caller");}
}
class Runner implements Runnable {
String str;
public Runner (String s) {this.str=s;}
public void run () { System.out.println (str.concat ("Runner"));}
}
and
public static void main (String[] args) throws InterruptedException, ExecutionException { ExecutorService es = Executors.newFixedThreadPool(2); Future f1 = es.submit (new Caller ("Call")); Future f2 = es.submit (new Runner ("Run")); String str1 = (String) f1.get(); String str2 = (String) f2.get();//line n1 System.out.println(str1+ ":" + str2);
}
What is the result?
Given the code fragments:
class Caller implements Callable<String> {
String str;
public Caller (String s) {this.str=s;}
public String call()throws Exception { return str.concat ("Caller");}
}
class Runner implements Runnable {
String str;
public Runner (String s) {this.str=s;}
public void run () { System.out.println (str.concat ("Runner"));}
}
and
public static void main (String[] args) throws InterruptedException, ExecutionException { ExecutorService es = Executors.newFixedThreadPool(2); Future f1 = es.submit (new Caller ("Call")); Future f2 = es.submit (new Runner ("Run")); String str1 = (String) f1.get(); String str2 = (String) f2.get();//line n1 System.out.println(str1+ ":" + str2);
}
What is the result?
正確答案: D
問題14
Given:
public class Emp {
String fName;
String lName;
public Emp (String fn, String ln) {
fName = fn;
lName = ln;
}
public String getfName() { return fName; }
public String getlName() { return lName; }
}
and the code fragment:
List<Emp> emp = Arrays.asList (
new Emp ("John", "Smith"),
new Emp ("Peter", "Sam"),
new Emp ("Thomas", "Wale"));
emp.stream()
//line n1
.collect(Collectors.toList());
Which code fragment, when inserted at line n1, sorts the employees list in descending order of fName and then ascending order of lName?
Given:
public class Emp {
String fName;
String lName;
public Emp (String fn, String ln) {
fName = fn;
lName = ln;
}
public String getfName() { return fName; }
public String getlName() { return lName; }
}
and the code fragment:
List<Emp> emp = Arrays.asList (
new Emp ("John", "Smith"),
new Emp ("Peter", "Sam"),
new Emp ("Thomas", "Wale"));
emp.stream()
//line n1
.collect(Collectors.toList());
Which code fragment, when inserted at line n1, sorts the employees list in descending order of fName and then ascending order of lName?
正確答案: D