使用不同的数据发出多个请求

// 假设我们有多个API端点需要请求
const endpoints = [
  'https://api.example.com/data1',
  'https://api.example.com/data2',
  'https://api.example.com/data3'
];

// 创建一个函数来发送单个请求
function fetchData(url) {
  return fetch(url).then(response => response.json());
}

// 使用Promise.all并行发送所有请求
Promise.all(endpoints.map(url => fetchData(url)))
  .then(results => {
    console.log('所有数据已获取:', results);
  })
  .catch(error => {
    console.error('请求失败:', error);
  });

function fetchDataWithRetry(url, retries = 3) {
  return fetch(url).then(response => {
    if (!response.ok) throw new Error('Network response was not ok');
    return response.json();
  }).catch(error => {
    if (retries > 0) return fetchDataWithRetry(url, retries - 1);
    throw error;
  });
}

// 按顺序发送请求
async function fetchDataSequentially(urls) {
  const results = [];
  for (const url of urls) {
    const data = await fetchData(url);
    results.push(data);
  }
  return results;
}

const maxConcurrentRequests = 5;
const requestQueue = [];
let activeRequests = 0;

function processQueue() {
  if (requestQueue.length === 0 || activeRequests >= maxConcurrentRequests) return;
  const { url, resolve, reject } = requestQueue.shift();
  activeRequests++;
  fetchData(url).then(resolve).catch(reject).finally(() => {
    activeRequests--;
    processQueue();
  });
}

function fetchDataWithQueue(url) {
  return new Promise((resolve, reject) => {
    requestQueue.push({ url, resolve, reject });
    processQueue();
  });
}