js实现下载文件并修改自己需要的名字

function download(url,filename){
getBlob(url,function(blob){
saveAs(blob,filename)
})
}

function getBlob(url,cb) {
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = 'blob';
xhr.onload = function() {
if (xhr.status === 200) {
cb(xhr.response);
}
};
xhr.send();
}

function saveAs(blob, filename) {
if (window.navigator.msSaveOrOpenBlob) {
navigator.msSaveBlob(blob, filename);
} else {
var link = document.createElement('a');
var body = document.querySelector('body');
link.href = window.URL.createObjectURL(blob);
link.download = filename;
link.style.display = 'none';
body.appendChild(link);
link.click();
body.removeChild(link);
window.URL.revokeObjectURL(link.href);
}
}