Skip to main content

Access to XMLHttpRequest at 'http://localhost:8080/xxx' from origin 'http://localhost:8080' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

 Due to browser same-origin policy restrictions. The Same Origin Policy is a convention. This is the main and essential security feature of the browser. Without the same-origin policy, normal browser functionality may be affected. The web is built on the same-origin policy, and browsers are just one implementation of the same-origin policy. The Same Origin Policy prevents JavaScript scripts from one domain from interacting with content from another domain. The so-called same origin (that is, the same domain) means that two pages have the same protocol, host and port.

Solution: 

1. Set the response header on the server side

res.setHeader("Access-Control-Allow-Origin","*")

2. Use third-party middleware such as cors

import cors from "cors"
app.use(cors())

3. Configure the proxy

//vue.config.js
devServer:{
    port:8088,
    proxy:"http://localhost:6060"
  }
//App,vue
methods:{
      getInfo(){
        axios.get("http://localhost:8088/info").then(
          response=>{
            console.log("success-666!!!")
            console.log(response.data)
          },
          err=>{
            console.log(err.message)
          }
        )
      }
    }

4. Configure multiple proxies

  devServer:{
   port:8088,
   proxy:{
        "/hello":{
          target:"http://localhost:6060",
          changeOrigin:true,
          pathRewrite:{"^/hello":""}
        },
        // "/xxx":{},
   }
  }
});

Labels:

Comments

Post a Comment

Popular posts from this blog

What is the difference between the box-size property content-box and border-box in the css box model?

 The box model is a very important concept in CSS layout, it includes content area, padding, border, and margin. Box models can be divided into two types: standard box models and IE box models. The box model, as the name suggests, is used to hold things, and the things it holds are the content of HTML elements. In other words, every visible HTML element is a box.
Post a Comment
Read more

Js uses recursive way to traverse the dom tree to dynamically create element nodes

 What is a dom tree? In short, DOM is the Document Object Model, which provides a structured representation for documents and defines how to access the document structure through scripts. DOM is composed of nodes. After the HTML is loaded, the rendering engine will generate a DOM tree in memory based on the HTML document. This article uses a small case to traverse the dom tree recursively. The core of the method is to determine whether the incoming data is an array, and then traverse the root node. Note that there must be an end condition when using recursion.
Post a Comment
Read more