js请求转发

// 客户端请求转发示例
function forwardRequest(url, options) {
    return fetch(url, options)
        .then(response => {
            if (response.ok) {
                return response.json();
            } else {
                throw new Error('Network response was not ok.');
            }
        })
        .then(data => {
            // 根据服务器响应决定下一步操作
            if (data.redirect) {
                return forwardRequest(data.redirect, options);
            } else {
                return data;
            }
        })
        .catch(error => {
            console.error('There has been a problem with your fetch operation:', error);
        });
}

// 使用示例
const requestOptions = {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ key: 'value' })
};

forwardRequest('/api/initial-endpoint', requestOptions)
    .then(result => {
        console.log('Final result:', result);
    });

let redirectCount = 0;
const MAX_REDIRECTS = 10;

function forwardRequestWithLimit(url, options) {
    if (redirectCount >= MAX_REDIRECTS) {
        throw new Error('Too many redirects');
    }
    redirectCount++;
    return fetch(url, options)
        .then(response => {
            if (response.ok) {
                return response.json();
            } else {
                throw new Error('Network response was not ok.');
            }
        })
        .then(data => {
            if (data.redirect) {
                return forwardRequestWithLimit(data.redirect, options);
            } else {
                return data;
            }
        })
        .catch(error => {
            console.error('There has been a problem with your fetch operation:', error);
        });
}

// 服务器端设置CORS头示例（Node.js）
app.use((req, res, next) => {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type');
    next();
});