Web服务器异常处理与日志记录示例

app.use((err, req, res, next) => {
  // 默认状态码
  const statusCode = err.statusCode || 500;
<p>// 记录错误日志
console.error(<code>${new Date().toISOString()} - ${req.method} ${req.url}</code>);
console.error(<code>状态码: ${statusCode}</code>);
console.error(<code>错误信息: ${err.message}</code>);
console.error(<code>堆栈: ${err.stack}</code>);</p><p>// 返回客户端友好的响应
res.status(statusCode).json({
success: false,
message: statusCode === 500 ? '服务器内部错误' : err.message
});
});</p>

class AppError extends Error {
  constructor(message, statusCode) {
    super(message);
    this.statusCode = statusCode;
    Error.captureStackTrace(this, this.constructor);
  }
}
<p>// 在业务逻辑中使用
if (!user) {
throw new AppError('用户不存在', 404);
}</p>

const winston = require('winston');
<p>const logger = winston.createLogger({
level: 'info',
format: winston.format.json(),
transports: [
new winston.transports.File({ filename: 'logs/error.log', level: 'error' }),
new winston.transports.File({ filename: 'logs/combined.log' })
]
});</p><p>// 在异常处理中使用
logger.error({
timestamp: new Date().toISOString(),
method: req.method,
url: req.url,
statusCode: err.statusCode || 500,
message: err.message,
stack: err.stack
});</p>