最新のOracle 1z0-809試験問題解答がズラリ [Q48-Q68]

最新のOracle 1z0-809試験問題解答がズラリ

1z0-809試験練習テスト問題（更新された209問あります)

Oracle 1Z1-809認定試験は、Java開発者にとって業界に認識された資格です。この認定は、開発者がJava言語とプログラミングに関する知識を実証するのに役立ちます。また、Javaアプリケーションを効率的に開発する際のプログラマーの習熟度を示しています。この試験が完了すると、候補者は「Oracle Certified Professional、Java SE 8プログラマー」のタイトルを獲得します。

Oracle 1Z0-809認定を達成することは、Javaプログラミングの分野でキャリアの見通しを強化したい専門家にとって非常に有益です。認定された個人は自分の分野の専門家として認識されており、この認定は高度なスキルと知識の証拠として機能します。さらに、この認定は、組織のために熟練したJavaの専門家を雇おうとしている雇用主によって高く評価されています。

1z1-809 Java SE 8 Programmer II試験の準備には、Javaプログラミング言語の概念とJava SE 8プラットフォームの包括的な理解が必要です。この認定試験は、効率的で最新のJava機能を取り入れたJavaコードを書き、デバッグ、テスト、トラブルシューティングできる候補者の能力を評価するように設計されています。さらに、この試験ではJava APIの知識とそのアプリケーション作成における使用方法もテストされます。Oracleは、試験のための候補者に、Java SE 8プログラミングの基本的なスキルの知識とJavaを使用してアプリケーションを開発する実践的な経験を持っていることを推奨しています。

質問 # 48
Given the code fragment:
UnaryOperator<Double> uo1 = s -> s*2;//line n1
List<Double> loanValues = Arrays.asList(1000.0, 2000.0);
loanValues.stream()
.filter(lv -> lv >= 1500)
.map(lv -> uo1.apply(lv))//line n2
.forEach(s -> System.out.print(s + " "));
What is the result?

A. 4000.0
B. 0
C. A compilation error occurs at line n2.
D. A compilation error occurs at line n1.

正解：C

質問 # 49
Given:
class FuelNotAvailException extends Exception { }
class Vehicle {
void ride() throws FuelNotAvailException {//line n1
System.out.println("Happy Journey!");
}
}
class SolarVehicle extends Vehicle {
public void ride () throws Exception {//line n2
super ride ();
}
}
and the code fragment:
public static void main (String[] args) throws FuelNotAvailException, Exception {
Vehicle v = new SolarVehicle ();
v.ride();
}
Which modification enables the code fragment to print Happy Journey!?

A. Replace line n1 with public void ride() throws FuelNotAvailException {
B. Replace line n2 with void ride() throws Exception {
C. Replace line n1 with protected void ride() throws Exception {
D. Replace line n2 with private void ride() throws FuelNotAvailException {

正解：C

質問 # 50
Which two class definitions fail to compile?

A. Option E
B. Option A
C. Option D
D. Option B
E. Option C

正解：D、E

質問 # 51
Given the code fragment:
List<Integer> nums = Arrays.asList (10, 20, 8):
System.out.println (
//line n1
);
Which code fragment must be inserted at line n1to enable the code to print the maximum number in the numslist?

A. nums.stream().max(Integer : : max).get()
B. nums.stream().max(Comparator.comparing(a -> a)).get()
C. nums.stream().map(a -> a).max()
D. nums.stream().max()

正解：D

質問 # 52
Which code fragment is required to load a JDBC 3.0 driver?

A. Connection con = Connection.getDriver("jdbc:xyzdata://localhost:3306/EmployeeDB");
B. Connection con = DriverManager.getConnection("jdbc:xyzdata://localhost:3306/EmployeeDB");
C. DriverManager.loadDriver ("org.xyzdata.jdbc.NetworkDriver");
D. Class.forName("org.xyzdata.jdbc.NetworkDriver");

正解：D

質問 # 53
Given:
public class SampleClass {
public static void main(String[] args) {
AnotherSampleClass asc = new AnotherSampleClass(); SampleClass sc = new SampleClass(); sc = asc; System.out.println("sc: " + sc.getClass()); System.out.println("asc: " + asc.getClass());
}}
class AnotherSampleClass extends SampleClass {
}
What is the result?

A. sc: class Object
asc: class AnotherSampleClass
B. sc: class SampleClass
asc: class AnotherSampleClass
C. sc: class AnotherSampleClass
asc: class SampleClass
D. sc: class AnotherSampleClass
asc: class AnotherSampleClass

正解：D

質問 # 54
Given:

What is the result?

A. 0 1 2
B. 6 8 10
C. 6 7 8
D. Compilation fails
E. 7 8 9

正解：C

質問 # 55
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(scr));
What is the result?

A. [Java ME: Jessy:Chicago, Java ME: Mark:Chicago][Java EE: Helen:Houston]
B. [Java EE: Helen:Houston][Java ME: Jessy:Chicago, Java ME: Mark:Chicago]
C. Java EEJava ME
D. A compilation error occurs.

正解：C

質問 # 56
Given the code fragment:

What is the result?

A. AnArrayIndexOutOfBoundsException is thrown at runtime
B. 0
C. 1
D. Compilation fails
E. 2

正解：B

質問 # 57
Given the code fragment:
Stream<Path> files = Files.walk(Paths.get(System.getProperty("user.home"))); files.forEach (fName -> {//line n1 try { Path aPath = fName.toAbsolutePath();//line n2 System.out.println(fName + ":"
+ Files.readAttributes(aPath, Basic.File.Attributes.class).creationTime ());
} catch (IOException ex) {
ex.printStackTrace();
});
What is the result?

A. A compilation error occurs at line n1.
B. All files and directories under the home directory are listed along with their attributes.
C. A compilation error occurs at line n2.
D. The files in the home directory are listed along with their attributes.

正解：B

質問 # 58
Given the code fragments:

and

What is the result?

A. France
Optional[NotFound]
B. France
Not Found
C. Optional[France]
Not Found
D. Optional [France]
Optional [NotFound]

正解：B

質問 # 59
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?

A. /app/./sys/log/server/exe/readme
B. /app/sys/log/readme/server/exe
C. /app/log/sys/server/exe/readme
D. /app/./sys/log/readme

正解：D

質問 # 60
Given the code fragments:

and

What is the result?

A. France
Optional[NotFound]
B. France
Not Found
C. Optional[France]
Not Found
D. Optional [France]
Optional [NotFound]

正解：B

質問 # 61
Which statement is true about the single abstract method of the java.util.function.Function interface?

A. It accepts one argument and returns boolean.
B. It accepts an argument and produces a result of any data type.
C. It accepts one argument and always produces a result of the same type as the argument.
D. It accepts one argument and returns void.

正解：B

解説：
http://winterbe.com/posts/2014/03/16/java-8-tutorial/ (functions)

質問 # 62
Given that these files exist and are accessible:

and given the code fragment:

Which code fragment can be inserted at line n1to enable the code to print only /company/emp?
Stream<Path> stream = Files.list (Paths.get ("/company"));

A. Paths.get ("/company"), 1,
(p,b) -> b.isDirectory (), FileVisitOption.FOLLOW_LINKS);
B. Stream<Path> stream = Files.walk (Paths.get ("/company"));
C. Stream<Path> stream = Files.find(
D. Stream<Path> stream = Files.list (Paths.get ("/company/emp"));

正解：A

質問 # 63
Given:

and this code fragment:

What is the result?

A. Open-Close-
Exception - 1
Open-Close-
B. Open-Close-Open-Close-
C. Open-Close-Open-
D. A compilation error occurs at line n1.

正解：D

質問 # 64
Given:

and the code fragment:

What is the result?
[Java EE: Helen:Houston]

A. [Java EE: Helen:Houston]
B. A compilation error occurs.
C. [Java ME: Jessy:Chicago, Java ME: Mark:Chicago]
Java EE
D. Java ME
[Java ME: Jessy:Chicago, Java ME: Mark:Chicago]

正解：B

解説：

質問 # 65
Given the code fragment:

What is the result?

A. text1text2text2text3
B. text1
C. [text1, text2]
D. text1text2

正解：D

質問 # 66
Given:
class FuelNotAvailException extends Exception { }
class Vehicle {
void ride() throws FuelNotAvailException {//line n1
System.out.println("Happy Journey!");
}
}
class SolarVehicle extends Vehicle {
public void ride () throws Exception {//line n2
super ride ();
}
}
and the code fragment:
public static void main (String[] args) throws FuelNotAvailException, Exception {
Vehicle v = new SolarVehicle ();
v.ride();
}
Which modification enables the code fragment to print Happy Journey!?

A. Replace line n1 with public void ride() throws FuelNotAvailException {
B. Replace line n2 with void ride() throws Exception {
C. Replace line n1 with protected void ride() throws Exception {
D. Replace line n2 with private void ride() throws FuelNotAvailException {

正解：C

質問 # 67
Given:
public enum USCurrency {
PENNY (1),
NICKLE(5),
DIME (10),
QUARTER(25);
private int value;
public USCurrency(int value) {
this.value = value;
}
public int getValue() {return value;}
}
public class Coin {
public static void main (String[] args) {
USCurrency usCoin =new USCurrency.DIME;
System.out.println(usCoin.getValue()):
}
}
Which two modifications enable the given code to compile? (Choose two.)