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我有一個簡單的客戶端在React中運行。我正在嘗試使用Axios向我已在本地運行的Go服務器發出GET請求。該陣營的代碼在端口3000上運行,於4000預檢不通過控制檢查訪問控制允許來源不存在
轉到服務器如果我粘貼GET請求本身在瀏覽器窗口中正常工作:http://localhost:4000/numberconverter?number=10&oldBase=10&newBase=2
我做了一些研究,發現this post,但插件和Chrome選項不起作用。這不是我所做的唯一研究,但似乎是最有前途的。我發現的大部分內容都不涉及Go服務器。
我也發現this post,但那也沒有解決我的問題。如果我取消註釋服務器中的代碼,它仍會失敗。
如果我更改允許的方法:
writer.Header().Set("Access-Control-Allow-Methods", "GET, POST, PATCH, PUT, DELETE, OPTIONS")
它失敗,出現405錯誤。服務器打印出這一點:
&{0xc4200f4000 0xc42000a500 {} 0x10ec430 true false false false 0xc4200143c0 {0xc420100000 map[Access-Control-Allow-Origin:[*] Access-Control-Allow-Methods:[GET, POST, PATCH, PUT, DELETE, OPTIONS] Content-Type:[text/plain; charset=utf-8] X-Content-Type-Options:[nosniff]] false false} map[Access-Control-Allow-Origin:[*] Access-Control-Allow-Methods:[GET, POST, PATCH, PUT, DELETE, OPTIONS] Content-Type:[text/plain; charset=utf-8] X-Content-Type-Options:[nosniff]] true 19 -1 405 false false [] 0 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0] [0 0 0 0 0 0 0 0 0 0] 0xc4200620e0 0}
我想我的問題是,這是否是在服務器端或客戶端的問題,以及我怎麼能解決這個問題?
客戶:
import React, {Component} from 'react';
import axios from 'axios';
class Converter extends Component {
constructor(props) {
super(props);
this.state = {
// number: 0,
// base: 10,
// newBase: 10
};
this.convertButtonPressed = this.convertButtonPressed.bind(this);
this.handleChange = this.handleChange.bind(this);
}
handleChange(event) {
const target = event.target;
const value = target.value;
const name = target.name;
this.setState({
[name]: value
});
}
convertButtonPressed(event) {
axios({
method: 'GET',
baseURL: 'http://localhost:4000/',
url: '/numberconverter',
headers: {
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Methods': 'GET, POST, PATCH, PUT, DELETE, OPTIONS',
'Access-Control-Allow-Headers': 'Origin, Content-Type, X-Auth-Token'
},
params: {
number: this.state.number,
oldBase: this.state.base,
newBase: this.state.newBase
}
});
}
render() {
return (
<div className="App">
<p>Number Converter</p>
<div>
Number:
<input name="number" onChange={this.handleChange} type="text" placeholder="Number"></input><br />
Base:
<input name="base" onChange={this.handleChange} type="text" placeholder="Base"></input><br />
New Base:
<input name="newBase" onChange={this.handleChange} type="text" placeholder="New Base"></input><br />
</div>
<button onClick={this.convertButtonPressed}>Convert</button>
</div>
);
}
}
export default Converter;
服務器:
package rest
// Example:
// http://localhost:3000/numberconverter?number=500000&oldBase=10&newBase=16
import (
"fmt"
"log"
"net/http"
"../converter"
)
// Start starts the server
func Start() {
//muxRouter := http.NewServeMux()
//muxRouter.HandleFunc("/numberconverter", numberconverter)
//http.Handle("/", muxRouter)
http.HandleFunc("/numberconverter", numberconverter)
log.Fatal(http.ListenAndServe(":4000", nil))
}
func numberconverter(writer http.ResponseWriter, response *http.Request) {
//writer.Header().Set("Access-Control-Allow-Origin", "*")
//writer.Header().Set("Access-Control-Allow-Methods", "*")
//writer.Header().Set("Content-Type", "text/html; charset=utf-8")
// Check if the method is a get
if response.Method != http.MethodGet {
http.Error(writer, http.StatusText(405), 405)
fmt.Println(writer)
return
}
number := response.FormValue("number")
oldBase := response.FormValue("oldBase")
newBase := response.FormValue("newBase")
result := converter.ConvertStringNumberToNewBase(number, oldBase, newBase)
fmt.Fprintf(writer, "%s base %s is %s in base %s", number, oldBase, result, newBase)
}
如果您取消註釋這些標題設置行,它會工作嗎?瀏覽器擴展絕對是解決這個問題的錯誤方法。你的用戶都不會擁有它們。 – captncraig
IIRC,'Access-Control-Allow-Methods'不能是'*'。它應該是一個方法列表。 –
[設置HTTP標頭]的可能重複(https://stackoverflow.com/questions/12830095/setting-http-headers) – captncraig