Flutter 中Dio 请求封装

1.定义请求方式枚举

// http_method.dart

class HttpMethod{
  static const String GET = "GET";
  static const String POST = "POST";
  static const String PUT = "PUT";
  static const String DELETE = "DELETE";
  static const String HEAD = "HEAD";
  static const String PATCH = "PATCH";
  static const String OPTIONS = "OPTIONS";
  static const String TRACE = "TRACE";
  static const String CONNECT = "CONNECT";
  static const String ALL = "ALL";
}

2.添加请求拦截器

//print_log_interceptor.dart
import 'package:dio/dio.dart';

class PrintLogInterceptor extends Interceptor {

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    print("请求url:${options.uri}");
    print("请求参数:${options.queryParameters}");
    print("请求头:${options.headers}");
    print("请求数据:${options.data}");
    return super.onRequest(options, handler);
  }

  @override
  void onResponse(Response response, ResponseInterceptorHandler handler) {
    print("响应数据:${response.data}");
    return super.onResponse(response, handler);
  }

  @override
  void onError(DioException err, ErrorInterceptorHandler handler) {
    print("错误信息:${err.error}");
    return super.onError(err, handler);
  }
}

2.对Dio进行封装

class DioInstance {
  static DioInstance? _instance;

  DioInstance._();

  static DioInstance instance() {
    return _instance ??= DioInstance._();
  }

  final Dio _dio = Dio();
  final _defaultTime = const Duration(seconds: 30);

  void initDio({
    required String baseUrl,
    String? httpMethod = HttpMethod.GET,
    Duration? connectTimeout,
    Duration? receiveTimeout,
    Duration? sendTimeout,
    ResponseType? responseType,
    String? contentType,
  }) {
    _dio.options = BaseOptions(
      method: httpMethod,
      baseUrl: baseUrl,
      connectTimeout: connectTimeout ?? _defaultTime,
      receiveTimeout: receiveTimeout ?? _defaultTime,
      sendTimeout: sendTimeout ?? _defaultTime,
      responseType: responseType ?? ResponseType.json,
      contentType: contentType,
    );
    _dio.interceptors.add(PrintLogInterceptor());
  }

// get 请求
  Future<Response> get({
    required String path,
    Map<String, dynamic>? param,
    Options? options,
    CancelToken? cancelToken,
  }) async {
    return await _dio.get(
      path,
      queryParameters: param,
      options: options ??
          Options(
            method: HttpMethod.GET,
            receiveTimeout: _defaultTime,
            sendTimeout: _defaultTime,
          ),
      cancelToken: cancelToken,
    );
  }

// post请求
  Future<Response> post({
    required String path,
    Object? data,
    Map<String, dynamic>? queryParameters,
    Options? options,
    CancelToken? cancelToken,
  }) async {
    return await _dio.post(
      path,
      data: data,
      queryParameters: queryParameters,
      options: options ??
          Options(
            method: HttpMethod.POST,
            receiveTimeout: _defaultTime,
            sendTimeout: _defaultTime,
          ),
      cancelToken: cancelToken,
    );
  }
}