Flutter网络日志记录插件pretty_http_logger的使用

pretty_http_logger 是一个用于Dart http 库的日志中间件库，它可以帮助开发者轻松地记录HTTP请求和响应信息。以下将详细介绍如何在Flutter项目中使用这个插件。

Getting Started

安装

首先，在你的pubspec.yaml文件中添加依赖：

dependencies:
  pretty_http_logger: any

然后执行flutter pub get来安装包。

导入

在需要使用的Dart文件中导入该库：

import 'package:pretty_http_logger/pretty_http_logger.dart';

使用pretty_http_logger

创建一个HttpWithMiddleware对象，并通过build构造函数传入预构建的中间件列表。这里我们使用HttpLogger作为中间件，它可以记录请求和响应的内容。

HttpWithMiddleware http = HttpWithMiddleware.build(middlewares: [
  HttpLogger(logLevel: LogLevel.BODY),
]);

此时你就可以像平常一样使用这个http对象发起网络请求了：

// Simple POST request
var response = await http.post(
  Uri.parse('https://jsonplaceholder.typicode.com/posts/'),
  body: {"testing": "1234"},
);

// Simple GET request
var response = await http.get(
  Uri.parse('https://jsonplaceholder.typicode.com/posts/'),
);

请求超时设置

你可以为请求指定超时时间，例如设置请求在30秒内完成：

HttpWithMiddleware http = HttpWithMiddleware.build(
  requestTimeout: Duration(seconds: 30),
  middlewares: [
    HttpLogger(logLevel: LogLevel.BODY),
  ],
);

对于可能出现的超时异常，你需要捕获并处理：

try {
  var response = await http.get(
    Uri.parse('https://jsonplaceholder.typicode.com/posts/'),
  );
} catch (e) {
  if (e is TimeoutException) {
    // Timed out
  }
}

使用HttpClientWithMiddleware

如果你希望保持与服务器的连接，则可以使用HttpClientWithMiddleware：

HttpClientWithMiddleware httpClient = HttpClientWithMiddleware.build(
  middlewares: [
    HttpLogger(logLevel: LogLevel.BODY),
  ],
);

var response = await httpClient.post(
  Uri.parse('https://jsonplaceholder.typicode.com/posts/'),
  body: {"testing": "1234"},
);

var response = await httpClient.get(
  Uri.parse('https://jsonplaceholder.typicode.com/posts/'),
);

// Don't forget to close the client once done.
httpClient.close();

自定义中间件

你可以通过继承MiddlewareContract类来自定义中间件逻辑。下面是一个简单的日志记录器示例：

class Logger extends MiddlewareContract {
  @override
  void interceptRequest(RequestData data) {
    print("Method: ${data.method}");
    print("Url: ${data.url}");
    print("Body: ${data.body}");
  }

  @override
  void interceptResponse(ResponseData data) {
    print("Status Code: ${data.statusCode}");
    print("Method: ${data.method}");
    print("Url: ${data.url}");
    print("Body: ${data.body}");
    print("Headers: ${data.headers}");
  }

  @override
  void interceptError(err) {
    print("Error: $err");
  }
}

你还可以修改请求数据或响应数据，例如为每个请求添加特定的头部信息：

class Logger extends MiddlewareContract {
  @override
  void interceptRequest(RequestData data) {
    // Adding content type to every request
    data.headers["Content-Type"] = "application/json";

    data.body = jsonEncode({
      "uniqueId": "some unique id",
      "data": data.body,
    });
  }

  @override
  void interceptResponse(ResponseData data) {
    // Unwrapping response from a structure
    data.body = jsonDecode(data.body)["data"];
  }

  @override
  void interceptError(err) {
    print("Error: $err");
  }
}

示例代码

为了更好地理解如何在实际项目中应用pretty_http_logger，这里提供了一个完整的示例程序：

import 'dart:convert';

import 'package:http/http.dart' as http;
import 'package:pretty_http_logger/pretty_http_logger.dart';

void main() async {
  final res = await baseRequest.get(Uri.parse('https://jsonplaceholder.typicode.com/todos/1'));
  print(jsonDecode(res.body));

  /// Observe the request and response log in the console
}

class _BaseRequest {
  static final HttpWithMiddleware _httpClient = HttpWithMiddleware.build(
    middlewares: [
      HttpLogger(logLevel: LogLevel.BODY),
    ],
  );

  static final HttpClientWithMiddleware _streamedHttpClient =
      HttpClientWithMiddleware.build(
    middlewares: [
      HttpLogger(logLevel: LogLevel.BODY),
    ],
  );

  Future<StreamedResponse> send(http.BaseRequest request) async {
    final response = await _streamedHttpClient.send(request);
    return response;
  }

  Future<http.Response> patch(Uri url,
      {Map<String, String>? headers, Object? body, Encoding? encoding}) async {
    final response = await _httpClient.patch(url, headers: headers);
    return response;
  }

  Future<http.Response> get(Uri url, {Map<String, String>? headers}) async {
    final response = await _httpClient.get(url, headers: headers);
    return response;
  }

  Future<http.Response> put(Uri url,
      {Map<String, String>? headers, Object? body, Encoding? encoding}) async {
    final response = await _httpClient.put(url, headers: headers);
    return response;
  }

  Future<http.Response> post(Uri url,
      {Map<String, String>? headers, Object? body, Encoding? encoding}) async {
    final response = await _httpClient.post(url, headers: headers, body: body);
    return response;
  }

  Future<http.Response> delete(Uri url,
      {Map<String, String>? headers, Object? body, Encoding? encoding}) async {
    final response = await _httpClient.delete(url, headers: headers, body: body);
    return response;
  }
}

final baseRequest = _BaseRequest();

以上就是pretty_http_logger的基本用法和一些高级特性。通过这些功能，你可以更方便地调试和监控你的网络请求。如果你有任何问题或者建议，欢迎访问GitHub仓库提交issue或pull request。