本篇文章为大家展示了如何从go源代码读懂interface接口,内容简明扼要并且容易理解,绝对能使你眼前一亮,通过这篇文章的详细介绍希望你能有所收获。
http库中,get方法:
1 | func Get(url string) (resp *Response, err error) |
Response:
123456789 | type Response struct { Status string // e.g. "200 OK" StatusCode int // e.g. 200 Proto string // e.g. "HTTP/1.0" ProtoMajor int // e.g. 1 ProtoMinor int // e.g. 0 Header Header Body io.ReadCloser |
io.ReadCloser:
1234 | type ReadCloser interface { Reader Closer} |
Reader:
123 | type Reader interface { Read(p []byte) (n int, err error)} |
Closer:
123 | type Closer interface { Close() error} |
不管是读取文件、网络等操作,都实现了相同的Reader接口。当传递[]byte进去,会将读取到的byte放置进去。成功会返回成功的个数。
123456789101112131415161718192021 | package mainimport ("net/http""fmt""os")func main(){ resp,err := http.Get("http://tmall.com")if err !=nil{ fmt.Println("Error:",err) os.Exit(1) } //设置大一点,read方法不会自动的扩容。 bs:=make([]byte,99999) //read函数将读取到的数据放入到bs中。 resp.Body.Read(bs) fmt.Println(string(bs))} |
123 | type Writer interface { Write(p []byte) (n int, err error)} |
1234567891011121314151617181920 | package mainimport ("net/http""fmt""os""io")func main(){ resp,err := http.Get("http://tmall.com")if err !=nil{ fmt.Println("Error:",err) os.Exit(1) }//读取resp.Body中的信息,写到os.Stdout中。os.Stdout实现了write接口,resp.Body实现了read接口。 io.Copy(os.Stdout,resp.Body)} |
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758 | func Copy(dst Writer, src Reader) (written int64, err error) {return copyBuffer(dst, src, nil)}---------func CopyBuffer(dst Writer, src Reader, buf []byte) (written int64, err error) {if buf != nil && len(buf) == 0 {panic("empty buffer in io.CopyBuffer") }return copyBuffer(dst, src, buf)}---------func copyBuffer(dst Writer, src Reader, buf []byte) (written int64, err error) {// If the reader has a WriteTo method, use it to do the copy.// Avoids an allocation and a copy.if wt, ok := src.(WriterTo); ok {return wt.WriteTo(dst) }// Similarly, if the writer has a ReadFrom method, use it to do the copy.if rt, ok := dst.(ReaderFrom); ok {return rt.ReadFrom(src) } size := 32 * 1024 if l, ok := src.(*LimitedReader); ok && int64(size) > l.N {if l.N < 1 { size = 1 } else { size = int(l.N) } }if buf == nil { buf = make([]byte, size)//分配 }for { //疯狂读取并写入 nr, er := src.Read(buf)if nr > 0 { nw, ew := dst.Write(buf[0:nr])if nw > 0 { written += int64(nw) }if ew != nil { err = ewbreak }if nr != nw { err = ErrShortWritebreak } }if er != nil {if er != EOF { err = er }break } }return written, err} |
12345678910111213141516171819202122232425262728293031 | package mainimport ("net/http""fmt""os""io")type logWriter struct{}func main(){ resp,err := http.Get("http://tmall.com")if err !=nil{ fmt.Println("Error:",err) os.Exit(1) } lw:= logWriter{} //读取resp.Body中的信息,写到os.Stdout中。os.Stdout实现了write接口,resp.Body实现了read接口。 io.Copy(lw,resp.Body)}func (logWriter) Write(bs []byte)(int,error){ fmt.Println(string(bs)) fmt.Println("Just wrote this many bytes",len(bs))return len(bs),nil} |
上述内容就是如何从go源代码读懂interface接口,你们学到知识或技能了吗?如果还想学到更多技能或者丰富自己的知识储备,欢迎关注亿速云行业资讯频道。
亿速云「云服务器」,即开即用、新一代英特尔至强铂金CPU、三副本存储NVMe SSD云盘,价格低至29元/月。点击查看>>
免责声明:本站发布的内容(图片、视频和文字)以原创、转载和分享为主,文章观点不代表本网站立场,如果涉及侵权请联系站长邮箱:is@yisu.com进行举报,并提供相关证据,一经查实,将立刻删除涉嫌侵权内容。