Java SE 25 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 Values, Text, Date-Time and Localization（値と日時と地域化）（出題比率 16%）
• Program Flow Control and Exception Handling（制御構造と例外処理）（出題比率 8%）
• Applying Object-Oriented Principles in Java Programs（OOP）（出題比率 32%）
• Arrays, Collections, Streams and Lambdas（コレクションとストリーム）（出題比率 12%）
• Packaging and Deploying Java Code（モジュールと配布）（出題比率 8%）
• Implementing Multithreading for Concurrent Execution（並行実行）（出題比率 12%）
• Input and Output Operations Using the Java I/O API（入出力）（出題比率 12%）

フリー問題

1. An int is divided by another int and the quotient is stored in a double. Why doe…
2. A method returns an Integer that happens to be null, and the caller stores it in…
3. Which parts of the printed text change when a date is formatted with a medium st…
4. Which requirement does the compiler place on a method that can throw a checked e…
5. A sealed interface permits two record classes, and a switch expression over that…
6. Where can code call a private helper that an interface declares?
7. Which pair decides between publishing an interface with default methods and an a…
8. Which member does a record declaration generate for its component list?
9. Which pair of methods must change together for a value type used as a key?
10. When does an object become eligible for reclamation by the collector?
11. Which requirement applies to every class named in a permits clause?
12. What must the earliest concrete subclass of an incomplete type provide?
13. What determines whether a hash based set treats two entries as duplicates?
14. Which choice lets a caller sort the same elements by two different keys?
15. How can a single Java source file be launched without declaring a class around t…
16. Why can a framework fail to read private members even though the package is avai…
17. Why can a map from the concurrent package be read while another writer updates i…
18. What does calling shutdown on an executor do with tasks that were already queued…
19. Which kind of stream should carry text that must be decoded with a named charset…
20. Why can output written through a buffered writer fail to appear on disk?