2nd/10_Wiki/Dev/Topic_Java/Java_FileOutputStream.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-fileoutputstream	Java FileOutputStream	Programming_Language	draft	conceptual		자바 FileOutputStream		B	0.88	2026-07-04	2026-07-04			java programming w3schools io fileoutputstream byte-stream	https://www.w3schools.com/java/java_fileoutputstream.asp

Java FileOutputStream

🎯 한 줄 통찰 (One-line insight)

FileOutputStream mirrors FileWriter's API surface almost exactly (.write(), overwrite-by-default, true as second constructor arg for append) — the only real difference is that it writes raw bytes (text.getBytes()) instead of character text, which is what makes it usable for binary files where FileWriter cannot go. [S1]

🧠 핵심 개념 (Core concepts)

• FileOutputStream — writes raw bytes; works for both text and binary data (images, PDFs, audio). [S1]
• .write(text.getBytes()) — converts a String to bytes before writing. [S1]
• Default overwrite behavior — same as FileWriter: replaces existing file content. [S1]
• Append mode — pass true as the second constructor argument: new FileOutputStream("filename.txt", true). [S1]
• Byte-level file copying — pairs with FileInputStream to copy any file type. [S1]

📖 세부 내용 (Details)

• Basic text write: try (FileOutputStream output = new FileOutputStream("filename.txt")) { output.write(text.getBytes()); }. [S1]
• Binary file copy: try (FileInputStream input = new FileInputStream("image.jpg"); FileOutputStream output = new FileOutputStream("copy.jpg")) { int b; while ((b = input.read()) != -1) { output.write(b); } }. [S1]
• Append mode: try (FileOutputStream output = new FileOutputStream("filename.txt", true)) { output.write(text.getBytes()); }. [S1]
• Class choice guide: FileWriter (basic text), BufferedWriter (large text, line handling), FileOutputStream (binary/raw byte control). [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

소스에서 모순되는 정보는 발견되지 않음.

🛠️ 적용 사례 (Applied in summary)

현재 발견된 실제 적용 사례가 없습니다 — FileInputStream과 짝을 이룬 이미지 파일 복사가 대표적 실전 응용이다. [S1]

💻 코드 패턴 (Code patterns)

Append mode with FileOutputStream (Java):

String text = "\nAppended text!";
try (FileOutputStream output = new FileOutputStream("filename.txt", true)) { // true = append
    output.write(text.getBytes());
    System.out.println("Successfully appended to file.");
} catch (IOException e) {
    System.out.println("Error writing file.");
}

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.88
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: Java Tutorial
• 관련 개념: Java FileInputStream, Java Files Write, Java BufferedWriter
• 참조 맥락: 바이트 단위 파일 쓰기 — FileInputStream과 짝을 이루어 파일 복사에 사용.

📚 출처 (Sources)

• [S1] W3Schools — Java FileOutputStream — https://www.w3schools.com/java/java_fileoutputstream.asp

📝 변경 이력 (Change history)

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