js 检测当前网络是否支持ipv6

function testIPv6Support() {
        return new Promise(function(resolve, reject) {
            let ipv6Url = 'https://api6.ipify.org?format=json';

            let xhr = new XMLHttpRequest();
            xhr.open('GET', ipv6Url, true);
            xhr.onload = function() {
                if (xhr.status === 200) {
                    try {
                        let response = JSON.parse(xhr.responseText);
                        let ipAddress = response.ip;
                        if (isIPv6Address(ipAddress)) {
                            resolve(true);
                        } else {
                            resolve(false);
                        }
                    } catch (error) {
                        resolve(false);
                    }
                } else {
                    resolve(false);
                }
            };
            xhr.onerror = function() {
                resolve(false);
            };
            xhr.send();
        });
    }

    function isIPv6Address(ipAddress) {
        // 检查IP地址是否为IPv6格式
        let regex = /^([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}$/;
        return regex.test(ipAddress);
    }
    // 使用示例
    testIPv6Support().then(function(supported) {
        if (supported) {
            ipv6Flag = true;
            console.log("当前网络支持IPv6");
        } else {
            console.log("当前网络不支持IPv6");
        }
    });