【golang实战】获取web提交的数据
背景
之前做 golang 开发的时候，用的是 beego 框架，框架的好处是，把所有工具都封装好了，在获取参数的时候，只要调用相应的方法，就能取得对应的数据。
而最近在从零开始，原生写一个小说爬虫管理的web服务功能时，发现自己所掌握的那点知识，并不能满足自己的开发需求，测试好多遍都未果，希望写下这篇记录贴，供以后回顾。
数据提交场景大致如下：
1、表单提交，纯粹的 Form 表单提交数据；
2、表单上传文件，利用 Form 表单上传文件；
3、ajax 提交 json 数据；
4、ajax 提交 表单数据；
5、ajax 上传文件；
下面我将对以上五种场景进行实际的示例展示，并采用 Fetch API 代替 ajax 发送请求。
示例
示例1：html表单提交数据
- html 表单
<form action="http://127.0.0.1:8088/api/task?debug=1" method="POST">
<input type="text" name="username" placeholder="username">
<input type="text" name="password" placeholder="password">
<input type="submit" value="Submit">
form>
- golang 接收数据
r.ParseForm() // 首先解析表单
fmt.Println("r.Form : ", r.Form)
fmt.Println("r.Form[\"username\"]", r.Form["username"]) // 数组索引方式获取数据
fmt.Println("r.Form.get(\"password\")", r.Form.Get("password")) // Get 方式获取数据
- 输出
r.Form : map[debug:[1] password:[testpass] username:[test]]
r.Form["username"] [test]
r.Form.get("password") testpass
示例2：html表单上传文件
- html表单
- golang 接收数据
fmt.Println("r.Form : ", r.Form)
file, fileHandler, _ := r.FormFile("file")
fmt.Println("File Header : ", fileHandler.Header)
fmt.Println("Filename : ", fileHandler.Filename)
b, _ :=ioutil.ReadAll(file) // 读取文件内容
fmt.Println(string(b))
- 输出
r.Form : map[debug:[1]]
File Header : map[Content-Disposition:[form-data; name="file"; filename="url.csv"] Content-Type:[application/octet-stream]]
Filename : url.csv
http://www.aaaa.com/test/index.html
http://www.ccccc.com/test/index.php
http://www.aaaa.com/test/login.php
http://www.aaaa.com
示例3：ajax 提交json数据, golang 接收数据时，需要从request的body中，将数据读出来
- html、fetch 提交数据
<button onclick="test()">testbutton>
<script>
function test() {
fetch("http://127.0.0.1:8088/api/task?debug=1", {
body: JSON.stringify({"username":"test", "password":"test_password"}),
method: "POST",
headers: {
"Accept": "application/json",
}
}
).then(response => response.json())
.then(data => {
console.log(data);
});
}
script>
- golang 接收数据
json,_ := ioutil.ReadAll(r.Body)
fmt.Println("Got params: ", string(json))
fmt.Println("Echo request: ", r)
fmt.Println("Echo request header: ", r.Header)
fmt.Println("Echo request body: ", r.Body)
fmt.Println("Echo remote addr: ", r.RemoteAddr)
fmt.Println("Echo host: ", r.Host)
fmt.Println("Echo request method: ", r.Method)
fmt.Println("Echo request UA: ", r.UserAgent())
- 输出：
Got params: {"username":"test","password":"test_password"}
Echo request: &{POST /api/task?debug=1 HTTP/1.1 1 1 map[Accept:[application/json] Accept-Encoding:[gzip, deflate, br] Accept-Language:[en-US,en;q=0.9] Connection:[keep-alive] Content-Length:[46] Content-Type:[text/plain;charset=UTF-8] Origin:[http://localhost:8099] Referer:[http://localhost:8099/test2.html] Sec-Fetch-Mode:[cors] Sec-Fetch-Site:[cross-site] User-Agent:[Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3879.0 Safari/537.36 Edg/78.0.249.1]] 0xc0001d6140 46 [] false 127.0.0.1:8088 map[debug:[1]] map[] map[] 127.0.0.1:61679 /api/task?debug=1 0xc0001ec210}
Echo request header: map[Accept:[application/json] Accept-Encoding:[gzip, deflate, br] Accept-Language:[en-US,en;q=0.9] Connection:[keep-alive] Content-Length:[46] Content-Type:[text/plain;charset=UTF-8] Origin:[http://localhost:8099] Referer:[http://localhost:8099/test2.html] Sec-Fetch-Mode:[cors] Sec-Fetch-Site:[cross-site] User-Agent:[Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3879.0 Safari/537.36 Edg/78.0.249.1]]
Echo request body: &{0xc0001f4020 false true {0 0} true false false 0x706ce0}
Echo remote addr: 127.0.0.1:61679
Echo host: 127.0.0.1:8088
Echo request method: POST
Echo request UA: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3879.0 Safari/537.36 Edg/78.0.249.1
示例4：ajax 提交表单数据
- html、fetch 提交数据
<button onclick="test()">testbutton>
<script>
function test() {
let formData = new FormData();
formData.set("username", "test");
formData.set("password", "test_password");
fetch("http://localhost:8088/api/task?debug=1", {
body: formData,
method: "POST",
headers: {
"Accept": "application/json"
}
}
).then(response => response.json())
.then(data => {
console.log(data);
});
}
script>
- golang 接收数据
r.ParseMultipartForm(32 << 20)
fmt.Println(r.Form)
fmt.Println("username: ", r.Form.Get("username"))
fmt.Println("password: ", r.Form.Get("password"))
- 输出
map[debug:[1] password:[test_password] username:[test]]
username: test
password: test_password
示例5：ajax 上传文件
- html、ajax 提交数据
<input type="file" name="test_file" id="test_file">
<button onclick="test()">testbutton>
<script>
function test() {
let formData = new FormData();
formData.set("test_file", document.getElementById("test_file").files[0]);
formData.set("password", "test_password");
fetch("http://localhost:8088/api/task?debug=1", {
body: formData,
method: "POST",
headers: {
"Accept": "application/json"
}
}
).then(response => response.json())
.then(data => {
console.log(data);
});
}
script>
- golang 接收数据
r.ParseForm()
file, fileHandle, _ := r.FormFile("test_file")
fmt.Println(fileHandle.Header, fileHandle.Filename, fileHandle.Size)
b, _ := ioutil.ReadAll(file)
fmt.Println(string(b))
fmt.Println("password: ", r.Form.Get("password"))
- 输出
map[Content-Disposition:[form-data; name="test_file"; filename="url.csv"] Content-Type:[application/octet-stream]] url.csv 136
http://www.aaaa.com/test/index.html
http://www.ccccc.com/test/index.php
http://www.aaaa.com/test/login.php
http://www.aaaa.com
password: test_password