---
id: java-debugging
title: "Java Debugging"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["자바 디버깅"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.87
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["java", "programming", "w3schools", "debugging"]
raw_sources: ["https://www.w3schools.com/java/java_debugging.asp"]
applied_in: []
github_commit: ""
---

# [[Java Debugging]]

## 🎯 한 줄 통찰 (One-line insight)
Print-statement debugging doubles as a crash locator — placing `println` calls before and after a suspect line (like a division) reveals exactly which line crashed, since the source shows "Before division" printing successfully while the line after the crash never executes at all. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Debugging** — identifying and fixing errors/bugs; involves reading error messages, tracing variable values, testing code in isolation. [S1]
- **Print-statement debugging** — the most basic technique: `System.out.println()` to check values and program flow. [S1]
- **Bracketing suspect code** — print before AND after a risky line to isolate exactly where a crash happens. [S1]
- **Variable-value checking** — print variable values to verify conditions behave as expected. [S1]
- **IDE debuggers** — breakpoints, step-through execution, real-time variable inspection (IntelliJ, Eclipse, NetBeans). [S1]
- **Debugging checklist** — read full error messages, check variable initialization, print to trace, watch for off-by-one errors, comment out code sections to isolate bugs. [S1]

## 📖 세부 내용 (Details)
- Crash isolation via print bracketing: `System.out.println("Before division"); int result = x / y; System.out.println("Result: " + result); // never runs`. [S1]
- Condition verification: `int age = 17; System.out.println("Age: " + age); if (age >= 18) {...} else {...}` — test by changing age to 18/19 and observing output. [S1]

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

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — print 문으로 크래시 지점을 특정하는 기법은 예외 처리(Try Catch) 학습 전 단계의 기초 디버깅 방법이다. [S1]

## 💻 코드 패턴 (Code patterns)
Bracketing a suspect line with print statements to locate a crash (Java):
```java
int x = 10;
int y = 0;
System.out.println("Before division"); // prints
int result = x / y;                    // crashes here
System.out.println("Result: " + result); // never runs
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.87
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[Java Tutorial]]
- **관련 개념:** [[Java Errors]], [[Java Try Catch]]
- **참조 맥락:** 에러 발견 후 디버깅 기법 — 예외 처리(try-catch) 챕터로 직접 이어짐.

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

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