js 判断url能否访问

async function checkUrl(url) {
  try {
    const response = await fetch(url, { method: 'HEAD' }); // 使用HEAD方法只获取响应头
    if (response.ok) {
      console.log('URL is accessible');
      return true;
    } else {
      console.log('URL is not accessible, status code:', response.status);
      return false;
    }
  } catch (error) {
    console.log('Error accessing URL:', error);
    return false;
  }
}

// 使用示例
checkUrl('https://www.example.com');

function checkUrl(url, callback) {
  const xhr = new XMLHttpRequest();
  xhr.open('HEAD', url, true);
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4) {
      if (xhr.status >= 200 && xhr.status < 400) {
        console.log('URL is accessible');
        callback(true);
      } else {
        console.log('URL is not accessible, status code:', xhr.status);
        callback(false);
      }
    }
  };
  xhr.onerror = function() {
    console.log('Error accessing URL');
    callback(false);
  };
  xhr.send();
}

// 使用示例
checkUrl('https://www.example.com', function(isAccessible) {
  console.log('Is URL accessible?', isAccessible);
});