RxSwift之深入解析URLSession的数据请求和数据处理
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一、请求网络数据
① 通过 rx.response 请求数据
- 如下所示，通过豆瓣提供的音乐频道列表接口获取数据，并将返回结果输出到控制台中：
"https://www.douban.com/j/app/radio/channels" -i -v
Success (2134ms): Status 200
返回的数据是： {"channels":[{"name_en":"Personal Radio","seq_id":0,"abbr_en":"My","name":"私人兆赫","channel_id":0},{"name":"华语","seq_id":0,"abbr_en":"","channel_id":"1","name_en":""},{"name":"欧美","seq_id":1,"abbr_en":"","channel_id":"2","name_en":""},{"name":"七零","seq_id":2,"abbr_en":"","channel_id":"3","name_en":""},{"name":"八零","seq_id":3,"abbr_en":"","channel_id":"4","name_en":""},{"name":"九零","seq_id":4,"abbr_en":"","channel_id":"5","name_en":""},{"name":"粤语","seq_id":5,"abbr_en":"","channel_id":"6","name_en":""},{"name":"摇滚","seq_id":6,"abbr_en":"","channel_id":"7","name_en":""},{"name":"民谣","seq_id":7,"abbr_en":"","channel_id":"8","name_en":""},{"name":"轻音乐","seq_id":8,"abbr_en":"","channel_id":"9","name_en":""},{"name":"原声","seq_id":9,"abbr_en":"","channel_id":"10","name_en":""},{"name":"Fly by midnight ","seq_id":10,"abbr_en":"","channel_id":"267","name_en":""},{"name":"独立","seq_id":11,"abbr_en":"","channel_id":"268","name_en":""},{"name":"爵士","seq_id":12,"abbr_en":"","channel_id":"13","name_en":""},{"name":"电子","seq_id":13,"abbr_en":"","channel_id":"14","name_en":""},{"name":"说唱","seq_id":14,"abbr_en":"","channel_id":"15","name_en":""},{"name":"R&B ","seq_id":15,"abbr_en":"","channel_id":"16","name_en":""},{"name":"日语","seq_id":16,"abbr_en":"","channel_id":"17","name_en":""},{"name":"韩语","seq_id":17,"abbr_en":"","channel_id":"18","name_en":""},{"name":"我的巴比伦恋人","seq_id":18,"abbr_en":"","channel_id":"259","name_en":""},{"name":"女声","seq_id":19,"abbr_en":"","channel_id":"20","name_en":""},{"name":"法语","seq_id":20,"abbr_en":"","channel_id":"22","name_en":""},{"name":"户外","seq_id":21,"abbr_en":"","channel_id":"151","name_en":""},{"name":"休息","seq_id":22,"abbr_en":"","channel_id":"152","name_en":""},{"name":"工作学习","seq_id":23,"abbr_en":"","channel_id":"153","name_en":""},{"name":"亢奋","seq_id":24,"abbr_en":"","channel_id":"154","name_en":""},{"name":"古典","seq_id":25,"abbr_en":"","channel_id":"27","name_en":""},{"name":"动漫","seq_id":26,"abbr_en":"","channel_id":"28","name_en":""},{"name":"咖啡馆","seq_id":27,"abbr_en":"","channel_id":"32","name_en":""},{"name":"舒缓","seq_id":28,"abbr_en":"","channel_id":"155","name_en":""},{"name":"18岁青春的召唤","seq_id":29,"abbr_en":"","channel_id":"262","name_en":""},{"name":"红歌","seq_id":30,"abbr_en":"","channel_id":"41","name_en":""},{"name":"圣诞","seq_id":31,"abbr_en":"","channel_id":"170","name_en":""},{"name":"运动","seq_id":32,"abbr_en":"","channel_id":"257","name_en":""},{"name":"英语","seq_id":33,"abbr_en":"","channel_id":"264","name_en":""},{"name":"豆瓣好歌曲","seq_id":34,"abbr_en":"","channel_id":"179","name_en":""},{"name":"Future Pop","seq_id":35,"abbr_en":"","channel_id":"266","name_en":""},{"name":"金属","seq_id":36,"abbr_en":"","channel_id":"187","name_en":""},{"name":"布鲁斯","seq_id":37,"abbr_en":"","channel_id":"188","name_en":""},{"name":"新歌","seq_id":38,"abbr_en":"","channel_id":"61","name_en":""},{"name":"世界杯","seq_id":39,"abbr_en":"","channel_id":"201","name_en":""},{"name":"朋克","seq_id":40,"abbr_en":"","channel_id":"76","name_en":""},{"name":"Easy ","seq_id":41,"abbr_en":"","channel_id":"77","name_en":""},{"name":"91.1 ","seq_id":42,"abbr_en":"","channel_id":"78","name_en":""},{"name":"乡村","seq_id":43,"abbr_en":"","channel_id":"269","name_en":""},{"name":"“砖”属音乐","seq_id":44,"abbr_en":"","channel_id":"145","name_en":""},{"name":"Pop","seq_id":45,"abbr_en":"","channel_id":"194","name_en":""},{"name":"拉丁","seq_id":46,"abbr_en":"","channel_id":"189","name_en":""}]}
- 请求示例如下：
// 创建URL对象
let urlString = "https://www.douban.com/j/app/radio/channels"
let url = URL(string:urlString)
// 创建请求对象
let request = URLRequest(url: url!)
// 创建并发起请求
URLSession.shared.rx.response(request: request).subscribe(onNext: {
(response, data) in
// 数据处理
let str = String(data: data, encoding: String.Encoding.utf8)
print("返回的数据是：", str ?? "")
}).disposed(by: disposeBag)
- 从以上示例，可以看到，不管请求成功与否都会进入到 onNext 这个回调中，如果需要根据响应状态进行一些相应操作，比如：
-
- 状态码在 200 ~ 300 则正常显示数据；
-
- 如果是异常状态码（比如：404）则弹出告警提示框。
- 可以借助 response 参数进行判断即可，把 url 改成一个错误的地址：
// 创建URL对象
let urlString = "https://www.douban.com/xxxxxxxxxx/app/radio/channels"
let url = URL(string:urlString)
// 创建请求对象
let request = URLRequest(url: url!)
// 创建并发起请求
URLSession.shared.rx.response(request: request).subscribe(onNext: {
(response, data) in
// 判断响应结果状态码
if 200 ..< 300 ~= response.statusCode {
let str = String(data: data, encoding: String.Encoding.utf8)
print("请求成功！返回的数据是：", str ?? "")
}else{
print("请求失败！")
}
}).disposed(by: disposeBag)
- 运行结果如下：
curl -X GET
"https://www.douban.com/xxxxxxxxxx/app/radio/channels" -i -v
Failure (1448ms): Status 404
请求失败！
② 通过 rx.data 请求数据
- rx.data 与 rx.response 的区别：
-
- 如果不需要获取底层的 response，只需知道请求是否成功，以及成功时返回的结果，那么建议使用 rx.data。
-
- 因为 rx.data 会自动对响应状态码进行判断，只有成功的响应（状态码为 200~300）才会进入到 onNext 这个回调，否则进入 onError 这个回调。
- 如果不需要考虑请求失败的情况，只对成功返回的结果做处理可以在 onNext 回调中进行相关操作：
// 创建URL对象
let urlString = "https://www.douban.com/j/app/radio/channels"
let url = URL(string:urlString)
// 创建请求对象
let request = URLRequest(url: url!)
// 创建并发起请求
URLSession.shared.rx.data(request: request).subscribe(onNext: {
data in
let str = String(data: data, encoding: String.Encoding.utf8)
print("请求成功！返回的数据是：", str ?? "")
}).disposed(by: disposeBag)
- 运行结果：
"https://www.douban.com/j/app/radio/channels" -i -v
Success (1449ms): Status 200
请求成功！返回的数据是： {"channels":[{"name_en":"Personal Radio","seq_id":0,"abbr_en":"My","name":"私人兆赫","channel_id":0},{"name":"华语","seq_id":0,"abbr_en":"","channel_id":"1","name_en":""},{"name":"欧美","seq_id":1,"abbr_en":"","channel_id":"2","name_en":""},{"name":"七零","seq_id":2,"abbr_en":"","channel_id":"3","name_en":""},{"name":"八零","seq_id":3,"abbr_en":"","channel_id":"4","name_en":""},{"name":"九零","seq_id":4,"abbr_en":"","channel_id":"5","name_en":""},{"name":"粤语&#以上是关于RxSwift之深入解析URLSession的数据请求和数据处理的主要内容，如果未能解决你的问题，请参考以下文章