如何在rest调用的post方法中接受特殊字符和空格？

var data = {
    name: 'John Doe',
    email: 'john.doe@example.com',
    message: 'Hello world!'
};

var encodedData = Object.keys(data).map(function(key) {
    return encodeURIComponent(key) + '=' + encodeURIComponent(data[key]);
}).join('&');

var xhr = new XMLHttpRequest();
xhr.open('POST', 'https://api.example.com/endpoint', true);
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
xhr.send(encodedData);

var data = {
    name: 'John Doe',
    email: 'john.doe@example.com',
    message: 'Hello world!'
};

var xhr = new XMLHttpRequest();
xhr.open('POST', 'https://api.example.com/endpoint', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(JSON.stringify(data));