[Q67-Q90] リアルOracle 1z1-819試験問題 [更新されたのは2022年]

リアルOracle 1z1-819試験問題 [更新されたのは2022年]

1z1-819試験問題集で合格させるのは更新されたのは2022年年最新のJava SE 11 Developer

Oracle 1z1-819 認定試験の出題範囲：

トピック	出題範囲
トピック 1	抽象クラスを含むサブクラスとスーパークラスを作成して使用する ラムダパラメーターを含むローカル変数型推論を使用する
トピック 2	自動モジュールを含むモジュラーアプリケーションのデプロイと実行 ラムダ式を使用した関数型インターフェースの実装
トピック 3	さまざまなロックメカニズムを使用して、ファイルシステムを含むリソースアクセスを保護し、ポリシーを管理し、特権コードを実行します スレッドセーフなコードを開発します
トピック 4	インスタンス、静的メソッド、オーバーロードメソッドなどのフィールドとメソッドを定義して使用します 配列とコレクションの操作
トピック 5	プリミティブとラッパークラスを使用します。これには、演算子、括弧、型の昇格、キャスト ComparatorおよびComparableインターフェイスを使用したコレクションと配列の並べ替えが含まれます
トピック 6	Javaオブジェクトにシリアル化および逆シリアル化の手法を実装する ネストされたクラスオブジェクトを含むJavaオブジェクトを宣言およびインスタンス化する
トピック 7	StringクラスとStringBuilderクラスを使用してテキストを処理する ポリモーフィズムとキャストを利用してメソッドを呼び出し、オブジェクトタイプと参照タイプを区別する

 

質問 67
Given:
LocalDate d1 = LocalDate.of(1997,2,7);
DateTimeFormatter dtf =
DateTimeFormatter.ofPattern( /*insert code here*/ );
System.out.println(dtf.format (d1));
Which pattern formats the date as Friday 7th of February 1997?

• A. "eeee dd+"th of"+ MMM yyyy"
• B. "eeee d+"th of"+ MMMM yyyy"
• C. "eeee dd'th of' MMM yyyy"
• D. "eeee d'th of' MMMM yyyy"

正解: C

 

質問 68
Given
:

What is the correct definition of the JsonField annotation that makes the Point class compile?
A)

B)

C)

• A. Option B
• B. Option C
• C. Option A

正解: C

 

質問 69
Given:

Which code, when inserted at one or more marked positions, would allow classes B and C to compile?

• A. @Override // position 3void x () {} // position 3@Override // position 3public void z() { } // position 3
• B. @Override // position 2public void z() { } // position 3
• C. public void z() { } // position 3
• D. implements A // position 1@Override // position 2

正解: B

 

質問 70
Given:

and

What is the result?

• A. A NullPointerException is thrown at run time.
• B. A ClassCastException is thrown at run time.
• C. 1
  Null
  null
• D. 1
  1
  1
• E. The compilation fails.

正解: E

解説:

 

質問 71
Given the code fragment:

You must make the countvariable thread safe.
Which two modifications meet your requirement? (Choose two.)

• A. replace line 2 with public static synchronized void main(String[] args) {
• B. replace line 1 with private AtomicInteger count = new AtomicInteger(0);and replace line 3 with test.count.incrementAndGet();
• C. replace line 3 with
  synchronized(test) {
  test.count++;
  }
• D. replace line 1 with private volatile int count = 0;
• E. replace line 3 with
  synchronized(test.count) {
  test.count++;
  }

正解: B,E

解説:
Explanation/Reference: https://stackoverflow.com/questions/15852123/java-thread-safe-counter/15852164

 

質問 72
Given:

Which two statements are true if the method is added to Bar? (Choose two.)

• A. public <T> Iterable<T> foo(Collection<T> arg) { ... } overrides Foo.foo.
• B. public Collection<String> foo(Collection<String> arg) { ... } overrides Foo.foo.
• C. public <T> Collection<T> foo(Collection<T> arg) { ... } overloads Foo.foo.
• D. public <T> Collection<T> bar(Collection<T> arg) { ... } overloads Foo.foo.
• E. public <T> Collection<T> foo(Stream<T> arg) { ... } overloads Foo.foo.
• F. public <T> List<T> foo(Collection<T> arg) { ... } overrides Foo.foo.

正解: A,F

 

質問 73
Which two statements are correct about modules in Java? (Choose two.)

• A. java.base exports all of the Java platforms core packages.
• B. module-info.java cannot be empty.
• C. A module must be declared in module-info.java file.
• D. By default, modules can access each other as long as they run in the same folder.
• E. module-info.java can be placed in any folder inside module-path.

正解: A,C

 

質問 74
Given:

What is the output?

• A. A runtime error is thrown.
• B. Message from Abstract Copier: Attempt00
• C. A compilation error is thrown.
• D. Message from Copier: Attempt00

正解: C

 

質問 75
Which module-info.java is correct for a service provider for a print service defined in the PrintServiceAPI module?
module PrintServiceProvider {

• A. requires PrintServiceAPI;
  provides org.printservice.spi.Print with
  com.provider.PrintService;
  }
  module PrintServiceProvider {
• B. requires PrintServiceAPI;
  exports org.printservice.spi.Print with
  com.provider.PrintService;
  }
• C. requires PrintServiceAPI;
  uses com.provider.PrintService;
  }
  module PrintServiceProvider {
• D. requires PrintServiceAPI;
  exports org.printservice.spi;
  }
  module PrintServiceProvider {

正解: D

 

質問 76
Given:

Which two lines can replace line 1 so that the Y class compiles? (Choose two.)

• A. set(map.values());
• B. set(map)
• C. map.forEach((k, v) -> set(v)));
• D. super.set(List<String> map)
• E. super.set(map.values());

正解: A,E

 

質問 77
Given:

What is the output?
banana orange apple lemon

• A. -----
  apple banana lemon orange
  -----
  -----
• B. banana orange apple lemon
  -----
  apple banana lemon orange
  -----
• C. -----
  -----
• D. -----
  -----
• E. -----
  banana orange apple lemon apple banana lemon orange
  banana orange apple lemon apple banana lemon orange

正解: E

解説:

 

質問 78
Which is a proper JDBC URL?

• A. jdbe.mysql.com://localhost:3306/database
• B. jdbc:mysql://localhost:3306/database
• C. http://localhost.mysql.com:3306/database
• D. http://localhost mysql.jdbc:3306/database

正解: B

 

質問 79
Given:

Which three are correct? (Choose three.)

• A. f1.foo(li) prints Bonjour le monde!
• B. f1.foo(li) prints Hola Mundo!
• C. f2.foo(li) prints Hola Mundo!
• D. f2.foo(li) prints Hello world!
• E. b1.foo(li) prints Bonjour le monde!
• F. b1.foo(li) prints Hello world!
• G. f2.foo(li) prints Bonjour le monde!
• H. b1.foo(li) prints Hola Mundo!
• I. f1.foo(li) prints Hello world!

正解: A,F,H

 

質問 80
var numbers = List.of(0,1,2,3,4,5,6,7,8,9);
You want to calculate the average of numbers. Which two codes will accomplish this? (Choose two.)

• A. double avg = numbers.stream().average().getAsDouble();
• B. double avg = numbers.stream().mapToInt (i -> i).average().parallel();
• C. double avg = numbers.parallelStream().mapToInt (m -> m).average().getAsDouble ();
• D. double avg = numbers.stream().collect(Collectors.averagingDouble(n -> n));
• E. double avg = numbers.stream().parallel().averagingDouble(a -> a);

正解: A,C

解説:

 

質問 81
Given the code fragment:

Which action enables Computatorclass to compile?

• A. change Line 5 to List<Double> numbers = List.of(5, 4, 6, 3, 7, 2, 8, 1, 9);
• B. change Line 1 to add throws NumberFormatException
• C. change Line 4 to for (Double n : collection) {
• D. change Line 2 to public Double sum ( C collection) {
• E. change Line 3 to Double sum = 0.0;

正解: D

 

質問 82
Given:

What is the result?

• A. b3
• B. 0
• C. b1
• D. 1
• E. b2
• F. The compilation fails due to an error in line 1.
• G. 2

正解: B

解説:

 

質問 83
Given:

What is the type of the local variable x?

• A. Character
• B. String[ ]
• C. char
• D. String

正解: D

 

質問 84
Given:

What is the result?

• A. 0
• B. 1
• C. 2
• D. 3

正解: B

 

質問 85
Given an application with a main module that has this module-info.java file:

Which two are true? (Choose two.)

• A. To compile without an error, the application must have at least one module in the module source path that provides an implementation of country.CountryDetails.
• B. A module providing an implementation of country.CountryDetails must have a requires main; directive in its module-info.java file.
• C. A module providing an implementation of country.CountryDetails can be compiled and added without recompiling the main module.
• D. To run without an error, the application must have at least one module in the module path that provides an implementation of country.CountryDetails.
• E. An implementation of country.countryDetails can be added to the main module.

正解: A,B

解説:
Reference:
/java-9-error-not-in-a-module-on-the-module-source- path

 

質問 86
Given:

and:

Which code, when inserted on line 10, prints the number of unique localities from the roster list?

• A. .map(Employee::getLocality)
  .distinct()
  .count();
• B. .map(e > e.getLocality())
  .collect(Collectors.toSet())
  .count();
• C. map(e > e.getLocality())
  .count();
• D. .filter(Employee::getLocality)
  .distinct()
  .count();

正解: D

 

質問 87
Given:

Which loop incurs a compile time error?

• A. the loop starting line 7
• B. the loop starting line 3
• C. the loop starting line 11
• D. the loop starting line 14

正解: D

 

質問 88
Given the code fragment:

What is the result?

• A. true false false
• B. false false true
• C. false true false
• D. false true true

正解: C

解説:

 

質問 89
Given:

Which two statements can be added at line 1 in Bar to successfully compile it? (Choose two.)

• A. public List<Integer> foo(Set<CharSequence> m) { ... }
• B. public List<Integer> foo(TreeSet<String> m) { ... }
• C. public List<Object> foo(Set<CharSequence> m) { ... }
• D. public ArrayList<Integer> foo(Set<String> m) { ... }
• E. public ArrayList<Number> foo(Set<CharSequence> m) { ... }
• F. public List<Integer> foo(Set<String> m) { ... }

正解: B,E

 

質問 90
......

1z1-819試験問題集、1z1-819練習テスト問題：https://www.jpntest.com/shiken/1z1-819-mondaishu