调试与边界

配置管理

application.properties vs application.yml

application.properties：

server.port=8080
spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=password

application.yml：

server:
  port: 8080

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mydb
    username: root
    password: password

Profile 环境切换

# application-dev.properties
server.port=8080
logging.level.root=DEBUG

# application-prod.properties
server.port=80
logging.level.root=WARN

激活 Profile：

java -jar app.jar --spring.profiles.active=prod

日志配置

logging.level.root=INFO
logging.level.com.example=DEBUG
logging.pattern.console=%d{yyyy-MM-dd HH:mm:ss} - %msg%n
logging.file.name=app.log

异常处理

@ControllerAdvice
public class GlobalExceptionHandler {
    
    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleNotFound(ResourceNotFoundException ex) {
        ErrorResponse error = new ErrorResponse(
            HttpStatus.NOT_FOUND.value(),
            ex.getMessage(),
            LocalDateTime.now()
        );
        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);
    }
    
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<Map<String, String>> handleValidation(
        MethodArgumentNotValidException ex
    ) {
        Map<String, String> errors = new HashMap<>();
        ex.getBindingResult().getFieldErrors().forEach(error ->
            errors.put(error.getField(), error.getDefaultMessage())
        );
        return ResponseEntity.badRequest().body(errors);
    }
}

调试技巧

启用 Debug 日志

debug=true

Actuator 健康检查

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

management.endpoints.web.exposure.include=health,info,metrics

访问：

• http://localhost:8080/actuator/health
• http://localhost:8080/actuator/info
• http://localhost:8080/actuator/metrics

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