2nd/10_Wiki/Dev/Topic_Java/Java_Try_Catch.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
java-try-catch	Java Try Catch	Programming_Language	draft	conceptual		exception handling 자바 예외 처리		B	0.9	2026-07-04	2026-07-04			java programming w3schools exceptions try-catch	https://www.w3schools.com/java/java_try_catch.asp

Java Try Catch

🎯 한 줄 통찰 (One-line insight)

finally runs regardless of outcome — even after a caught exception — making it the guaranteed place for cleanup code that must execute whether the try block succeeded or the catch block fired, distinct from code placed after the whole try/catch structure. [S1]

🧠 핵심 개념 (Core concepts)

• Exception — Java's technical term for the error object thrown when something goes wrong at runtime. [S1]
• try — defines a block of code to test for errors during execution. [S1]
• catch(Exception e) — defines a block that runs if an error occurs in the try block. [S1]
• finally — runs after try/catch regardless of the result. [S1]
• throw — creates and raises a custom exception, paired with an exception type (e.g. ArithmeticException). [S1]
• Common exception types — ArithmeticException, ArrayIndexOutOfBoundsException, ClassNotFoundException, FileNotFoundException, InputMismatchException, IOException, NullPointerException, NumberFormatException, StringIndexOutOfBoundsException. [S1]

📖 세부 내용 (Details)

• Uncaught exception: int[] myNumbers = {1, 2, 3}; System.out.println(myNumbers[10]); // ArrayIndexOutOfBoundsException: 10. [S1]
• Caught with try/catch: try { System.out.println(myNumbers[10]); } catch (Exception e) { System.out.println("Something went wrong."); }. [S1]
• With finally: try {...} catch (Exception e) {...} finally { System.out.println("The 'try catch' is finished."); } — finally always runs. [S1]
• Custom throw: static void checkAge(int age) { if (age < 18) { throw new ArithmeticException("Access denied - You must be at least 18 years old."); } else { System.out.println("Access granted - You are old enough!"); } }. [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — 나이 체크에 throw로 커스텀 예외를 발생시키는 패턴이 실전 검증 로직의 대표 사례다. [S1]

💻 코드 패턴 (Code patterns)

Try/catch/finally with custom throw (Java):

static void checkAge(int age) {
    if (age < 18) {
        throw new ArithmeticException("Access denied - You must be at least 18 years old.");
    } else {
        System.out.println("Access granted - You are old enough!");
    }
}

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.90
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: Java Tutorial
• 관련 개념: Java Debugging, Java Exceptions Multiple, Java Try Catch Resources
• 참조 맥락: 예외 처리의 기초 문법 — 다중 예외 처리(Multiple Exceptions) 챕터로 이어짐.

📚 출처 (Sources)

• [S1] W3Schools — Java Exceptions - Try...Catch — https://www.w3schools.com/java/java_try_catch.asp

📝 변경 이력 (Change history)

• 2026-07-04: Initial draft synthesized from the W3Schools "Java Exceptions - Try...Catch" page (Astra wiki-curation, P-Reinforce v3.1 format).