docs(10_Wiki): 위키 구조 정리 — 언어 튜토리얼 카테고리 폴더 제거 + 신규 자산 동기화

Topic_CSS/Topic_HTML/Topic_JavaScript/Topic_Prompt/Topic_Comfyui 등 기존 카테고리 폴더를 정리하고, Topic_Graphic/Dev 등 신규 산출물과 Topics 내부 세션/메모리 기록을 동기화.
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+---
+id: java-files-write
+title: "Java Files Write"
+category: "Programming_Language"
+status: "draft"
+verification_status: "conceptual"
+canonical_id: ""
+aliases: ["FileWriter", "자바 파일 쓰기"]
+duplicate_of: ""
+source_trust_level: "B"
+confidence_score: 0.88
+created_at: 2026-07-04
+updated_at: 2026-07-04
+review_reason: ""
+merge_history: []
+tags: ["java", "programming", "w3schools", "files", "io", "write", "filewriter"]
+raw_sources: ["https://www.w3schools.com/java/java_files_write.asp"]
+applied_in: []
+github_commit: ""
+---
+
+# [[Java Files Write]]
+
+## 🎯 한 줄 통찰 (One-line insight)
+FileWriter OVERWRITES a file by default — appending requires explicitly passing `true` as a SECOND constructor argument (`new FileWriter("filename.txt", true)`), which is easy to miss since the single-argument constructor silently discards existing content. [S1]
+
+## 🧠 핵심 개념 (Core concepts)
+- **`FileWriter`** — the simplest class for writing text to a file. [S1]
+- **`.write(text)` + `.close()`** — writes then must manually close (or use try-with-resources). [S1]
+- **Default behavior: overwrite** — an existing file's content is replaced unless append mode is used. [S1]
+- **Append mode** — pass `true` as the second constructor argument: `new FileWriter("filename.txt", true)`. [S1]
+- **Auto-creation** — if the file doesn't exist, Java creates it before appending. [S1]
+- **Alternative write classes** — FileWriter (easiest, basic text), BufferedWriter (faster, better for large files), FileOutputStream (best for binary data). [S1]
+
+## 📖 세부 내용 (Details)
+- Basic write with manual close: `FileWriter myWriter = new FileWriter("filename.txt"); myWriter.write("Files in Java might be tricky, but it is fun enough!"); myWriter.close();`. [S1]
+- Try-with-resources (auto-close): `try (FileWriter myWriter = new FileWriter("filename.txt")) { myWriter.write("..."); } catch (IOException e) {...}`. [S1]
+- Append mode: `try (FileWriter myWriter = new FileWriter("filename.txt", true)) { myWriter.write("\nAppended text!"); }`. [S1]
+
+## ⚖️ 모순 및 업데이트 (Contradictions & updates)
+- **기본 동작이 덮어쓰기**: 추가(append)하려면 반드시 두 번째 인자로 true를 전달해야 한다는 점이 강조됨. [S1]
+
+## 🛠️ 적용 사례 (Applied in summary)
+현재 발견된 실제 적용 사례가 없습니다 — 로그 파일에 내용을 추가하는 등 append 모드는 실전에서 자주 쓰이는 패턴이다. [S1]
+
+## 💻 코드 패턴 (Code patterns)
+Append mode via the two-argument FileWriter constructor (Java):
+```java
+try (FileWriter myWriter = new FileWriter("filename.txt", true)) { // true = append
+    myWriter.write("\nAppended text!");
+    System.out.println("Successfully appended to the file.");
+} catch (IOException e) {
+    System.out.println("An error occurred.");
+}
+```
+
+## ✅ 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 Files Create]], [[Java Files Read]], [[Java BufferedWriter]], [[Java FileOutputStream]]
+- **참조 맥락:** 파일에 텍스트 쓰기 — Read 챕터로 이어지며, BufferedWriter/FileOutputStream은 후속 챕터에서 심화.
+
+## 📚 출처 (Sources)
+- [S1] W3Schools — Java Write To Files — https://www.w3schools.com/java/java_files_write.asp
+
+## 📝 변경 이력 (Change history)
+- 2026-07-04: Initial draft synthesized from the W3Schools "Java Write To Files" page (Astra wiki-curation, P-Reinforce v3.1 format).