---
id: java-bufferedwriter
title: "Java BufferedWriter"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["자바 BufferedWriter"]
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", "io", "bufferedwriter", "character-stream"]
raw_sources: ["https://www.w3schools.com/java/java_bufferedwriter.asp"]
applied_in: []
github_commit: ""
---

# [[Java BufferedWriter]]

## 🎯 한 줄 통찰 (One-line insight)
`BufferedWriter`'s `newLine()` is the platform-independent way to insert line breaks — unlike hardcoding `"\n"` in a string, `newLine()` uses the correct line separator for whatever OS the program runs on, though the source primarily frames it as a convenience method rather than a portability guarantee. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`BufferedWriter`** — writes text line/string at a time; must be paired with `FileWriter` (which opens/creates the file). [S1]
- **`.newLine()`** — inserts a line break, an alternative to embedding `\n` manually. [S1]
- **Default overwrite** — like FileWriter, replaces existing file content unless append mode is used. [S1]
- **Append mode** — pass `true` to the underlying `FileWriter` constructor: `new FileWriter("filename.txt", true)`. [S1]

## 📖 세부 내용 (Details)
- Basic write with newLine(): `try (BufferedWriter bw = new BufferedWriter(new FileWriter("filename.txt"))) { bw.write("First line"); bw.newLine(); bw.write("Second line"); } catch (IOException e) {...}`. [S1]
- Append mode: `try (BufferedWriter bw = new BufferedWriter(new FileWriter("filename.txt", true))) { bw.newLine(); bw.write("Appended line"); }`. [S1]
- Class comparison: FileWriter (simple/quick), BufferedWriter (faster for large files, easy newLine()), FileOutputStream (binary files). [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
소스에서 모순되는 정보는 발견되지 않음.

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 여러 줄의 텍스트를 newLine()으로 구분하며 파일에 쓰는 표준 패턴이다. [S1]

## 💻 코드 패턴 (Code patterns)
Writing multiple lines with newLine() (Java):
```java
try (BufferedWriter bw = new BufferedWriter(new FileWriter("filename.txt"))) {
    bw.write("First line");
    bw.newLine(); // add line break
    bw.write("Second line");
    System.out.println("Successfully wrote to the 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 BufferedReader]], [[Java FileOutputStream]], [[Java Files Write]]
- **참조 맥락:** 버퍼링을 통한 빠른 텍스트 쓰기 — Data Structures & Collections 섹션으로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — Java BufferedWriter — https://www.w3schools.com/java/java_bufferedwriter.asp

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "Java BufferedWriter" page (Astra wiki-curation, P-Reinforce v3.1 format).