JS实现HTML页面下载文件的两种核心方式

<a href="/user/test/xxxx.txt" rel="external nofollow"  download="文件名.txt">点击下载</a>

<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		 <a href="http://171.**.96.**:****/d/c833945c11/files/?p=/plugins.maintain.CheckLinePartTask/cebab687-6dc5-4128-b7d9-8bc2fe369598.png&raw=1" rel="external nofollow"  
		 		download="test.png">点击下载</a>
	</body>
</html>

var $eleBtn1 = $("#btn1");
var $eleBtn2 = $("#btn2");
//已知一个下载文件的后端接口：https://codeload.github.com/douban/douban-client/legacy.zip/master
//方法一：window.open()
$eleBtn1.click(function(){
    window.open("https://codeload.github.com/douban/douban-client/legacy.zip/master");
});

//方法二：通过form
$eleBtn2.click(function(){
    var $eleForm = $("<form method='get'></form>");
    $eleForm.attr("action","https://codeload.github.com/douban/douban-client/legacy.zip/master");
    $(document.body).append($eleForm);
    //提交表单，实现下载
    $eleForm.submit();
});

var eleTextarea = document.querySelector('textarea');
var eleButton = document.querySelector('input[type="button"]');
// 下载文件方法
var funDownload = function (content, filename) {
  //content是要下载页面的html代码，filename是下载后的文件名称
    var eleLink = document.createElement('a');
    eleLink.download = filename;
    eleLink.style.display = 'none';
    // 字符内容转变成blob地址
    var blob = new Blob([content]);
    eleLink.href = URL.createObjectURL(blob);
    // 触发点击
    document.body.appendChild(eleLink);
    eleLink.click();
    // 然后移除
    document.body.removeChild(eleLink);
};
//判断浏览器是否支持a标签的download属性
if ('download' in document.createElement('a')) {
    // 作为test.html文件下载
    eleButton.addEventListener('click', function () {
        funDownload(eleTextarea.value, 'test.html');    
    });
} else {
    eleButton.onclick = function () {
        alert('浏览器不支持');    
    };
}