获取请求 response.json() returns 未定义

Question

我想获取对我的 spring 启动服务器的获取请求，我得到了我的 json，但是当我想 return 它时，出现了一个未定义的错误.我是 Javascript 的新手，所以答案可能很明显，但我找不到！

抱歉英语不好，谢谢！

代码：

function httpGet(theUrl)
{
    fetch(theUrl,
    {
        method: "GET",
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
    })
    .then (response => response.json())
    .then(response => {
        console.log(response); // Logs the json array
        return response; // Returns undefined
    });
}

使用异步编辑，仍然无效： https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch

async function httpGet(theUrl)
{
    const response = await fetch(theUrl,
    {
        method: "GET",
        headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
    });
    const jsonResponse = await response.json()
    .then(data => {
        return data;
    });
}

这是我的反应组件功能：

 function Admin(){
    const data =  httpGet('https://jsonplaceholder.typicode.com/users'); // Not Working
    console.log(data);  
    return(
        <div>
            <h1> Admin Page</h1>
        </div>
    )
}

Answer 1

function httpGet(theUrl) {
  return fetch(theUrl, {
      method: "GET",
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
    })
    .then(response => response.json());
}


(async() => {
  const response = await httpGet('https://jsonplaceholder.typicode.com/users');
  console.log(response);
})();

Answer 2

您可以使用 async 和 await 来执行此操作，这样可以轻松编写和理解代码。

这是您可以使用的示例。

const httpGet = async (theUrl) => {
  const response = await fetch(theUrl, {
    method: "GET",
    headers: {
      Accept: "application/json",
      "Content-Type": "application/json"
    }
  });
  return response.json();
};

// calling the method

(async () => {
  const data = await httpGet("https://jsonplaceholder.typicode.com/posts/1")
  console.log("response data is: ", data)
})()

获取请求 response.json() returns 未定义

Fetch Request response.json() returns undefined

javascript

fetch

fetch-api