Java SE 21 Developer Professional 試験対策問題集

模擬試験モードの設定

上記は本サイトの模擬試験モードの設定値です。実際の試験の出題数・制限時間・合格基準は、各認定プログラムの公式サイトでご確認ください。

出題分野

• Handling Date, Time, Text, Numeric and Boolean Values（値の操作）（出題比率 12%）
• Implementing Localization（ローカライズの実装）（出題比率 8%）
• Logging, Annotations and Generics（ロギング・注釈・ジェネリクス）（出題比率 8%）
• Controlling Program Flow（プログラムの流れの制御）（出題比率 8%）
• Using Object-Oriented Concepts in Java（オブジェクト指向の概念）（出題比率 12%）
• Handling Exceptions（例外の処理）（出題比率 8%）
• Working with Arrays and Collections（配列とコレクション）（出題比率 8%）
• Working with Streams and Lambda expressions（ストリームとラムダ式）（出題比率 8%）
• Packaging and Deploying Java Code（モジュールとパッケージング）（出題比率 8%）
• Managing Concurrent Code Execution（並行実行の管理）（出題比率 12%）
• Using Java I/O API（入出力 API の利用）（出題比率 8%）

フリー問題

1. A developer writes the single line int average = (7 + 8) / 2; and expects the va…
2. A method builds one line of text by concatenating a few thousand short pieces in…
3. A properties based bundle set has a base name. Which file name holds the entries…
4. Which expression is the recommended way to obtain a Locale for a language and co…
5. What is the difference between declaring the type parameter on a class and decla…
6. Loggers are obtained by name. How are Logger instances related to one another, a…
7. A method must map each value of an enum with twelve constants to a different str…
8. Two loops are nested. When a matching element is found in the inner loop, the pr…
9. A class declares a static initializer, an instance initializer, a static field w…
10. A record is declared with two components and needs to reject negative values for…
11. A custom exception should report the low level failure that led to it. What is t…
12. A try block completes without throwing anything, and the method has a matching c…
13. An ArrayDeque is used as a stack. Which pair of operations pushes an element and…
14. An array of five elements is created with new String[5] and nothing else is done…
15. A pipeline is built from a list with a filter step and a map step, and the resul…
16. A grouping must collect one field of each element instead of the whole element. …
17. A module declaration needs to let other modules use the types in one of its pack…
18. A Callable throws a checked exception while it runs inside an executor. What doe…
19. Which statement correctly describes virtual threads as they were finalized in Ja…
20. Which statement about the three standard streams of System is correct?