js上传数据到后台

const data = { username: 'example', password: 'password123' };

fetch('https://example.com/api/login', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify(data)
})
.then(response => response.json())
.then(data => {
  console.log('Success:', data);
})
.catch((error) => {
  console.error('Error:', error);
});

const input = document.querySelector('input[type="file"]');
input.addEventListener('change', function(event) {
  const file = event.target.files[0];
  const formData = new FormData();
  formData.append('file', file);

  fetch('https://example.com/api/upload', {
    method: 'POST',
    body: formData
  })
  .then(response => response.json())
  .then(data => {
    console.log('Success:', data);
  })
  .catch((error) => {
    console.error('Error:', error);
  });
});