Golang 学习 - 01

信号测试web hello world表单处理

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1. 信号

1.1 常用信号

信号值动作说明SIGUP1Term终端连接中断SIGINT2Term用户发送INTR:ctrl+cSIGQUIT3Core用户发送QUIT:ctrl+/SIGKILL9Term无条件结束，无法捕获SIGTERM15Term结束，可被捕获

1.2 go实现

创建管道，连接os.Signalos.Signal Notify 指定信号while ：=<-c 循环捕获switch/case 处理信号 c := make(chan os.Signal, 1) signal.Notify(c, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGINT) for { s := <-c fmt.Println("recv sig") switch s { case syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGINT: fmt.Println("quit ...") return case syscall.SIGHUP: fmt.Println("sighup ...") default: fmt.Println("default ...") return } }

2. 测试

2.1 测试框架

创建测试

创建后缀名为XX_test.go 的文件

创建函数 TestXXX(test *testing.T){}

记录测试信息

log记录信息，Fatalf用于记录严重错误，FailNow标记错误信息并立刻退出，

func TestRunSampleA(t *testing.T) { t.Log("test a") for i := 0; i != 10; i++ { if i > 6 && i <= 8 { // 记录错误信息 t.Errorf("err output %d", i) //标记当前错误 t.Fail() } else if i > 8 { // 记录严重信息 t.Fatalf("curical output %d", i) //标记错误并退出 t.FailNow() } else { //记录信息 t.Logf("curr output %d", i) } } t.Log("expect success return ..") }

其他测试

Skip 跳过当前测试 Parallel开启并行测试，Example启用一条样例测试

func ExampleTestA(){ fmt.Println("hello") //Output:hello a }

3.web基础

3.1 hello world

func main() { http.HandleFunc("/",sayHello) //设置路由 err := http.ListenAndServe(":9090",nil) //设置监听 if err!=nil{ log.Fatal("listen and serve ",err) } } func sayHello(response http.ResponseWriter, request *http.Request) { // sample // http://localhost:9090 // http://localhost:9090/?url_long=111&url_long=222 request.ParseForm() //解析参数 fmt.Println(request.Form) //表单 fmt.Println("path ", request.URL.Path) //路由地址 fmt.Println("scheme ",request.URL.Scheme) //携带参数 fmt.Println(request.Form["url_long"]) for k,v := range request.Form{ //循环输出 fmt.Println("key ",k) fmt.Println("value ",v) } fmt.Fprintf(response,"hello go lang! ") }

3.2 表单

表单方法 func login(response http.ResponseWriter, request *http.Request) { fmt.Println("method ", request.Method) if request.Method == "GET" { t, _ := template.ParseFiles("login.gtpl") log.Println(t.Execute(response, nil)) } else { request.ParseForm() fmt.Println("username ", request.Form["username"]) fmt.Println("password ", request.Form["password"]) } }

字段解析 正则表达式 略

防止跨站攻击

fmt.Println("username ",template.HTMLEscapeString(request.Form.Get("username"))) fmt.Println("password ",template.HTMLEscapeString(request.Form.Get("password"))) template.HTMLEscape(response,[]byte(request.Form.Get("username")))

防止多次递交表单

增加token生成和检测，在gtpl中增加token的隐藏字段

func login(response http.ResponseWriter, request *http.Request) { fmt.Println("method ", request.Method) if request.Method == "GET" { currtime := time.Now().Unix() h := md5.New() io.WriteString(h, strconv.FormatInt(currtime,10)) token := fmt.Sprintf("%x",h.Sum(nil)) t, _ := template.ParseFiles("login.gtpl") log.Println(t.Execute(response, token)) } else { request.ParseForm() //防止跨域攻击 token :=request.Form.Get("token") if token !=""{ //test token fmt.Println("token", token) } else{ // invalid ! fmt.Println("no token") } fmt.Println("username ",template.HTMLEscapeString(request.Form.Get("username"))) fmt.Println("password ",template.HTMLEscapeString(request.Form.Get("password"))) template.HTMLEscape(response,[]byte(request.Form.Get("username"))) } }

处理文件上传

为表单增加属性， enctype=“multipart/form-data”表单处理的实现 关键函数 ： request.ParseMultipartForm， f,err := os.OpenFile("./test/"+handler.Filename,os.O_WRONLY|os.O_CREATE,0666) func upload(response http.ResponseWriter, request *http.Request) { fmt.Println("method",request.Method) if request.Method =="GET"{ currtime := time.Now().Unix() h:= md5.New() io.WriteString(h,strconv.FormatInt(currtime,10)) token :=fmt.Sprintf("%x",h.Sum(nil)) t,_ := template.ParseFiles("upload.gtpl") t.Execute(response,token) } else { request.ParseMultipartForm(32<<20) //表示最大传输大小，超出大小将转存到系统临时文件 file,handler,err := request.FormFile("uploadfile") if err != nil{ fmt.Println(err) return } defer file.Close() fmt.Fprintf(response,"%v", handler.Header) fmt.Println("current upload filename ",handler.Filename) f,err := os.OpenFile("./test/"+handler.Filename,os.O_WRONLY|os.O_CREATE,0666) if err != nil{ fmt.Println("err 123",err) return } defer f.Close() io.Copy(f,file) } } 客户端实现， 略