JS中调用后缀名为json的文件出错：ERROR 404.3 Not Found for JSON file

我们在使用前台插件的时候，demo中的JS会调用后缀名为json的文件，作为json数据传输给页面，例如下面的FacyTree中的Demo

$("#tree").fancytree({
			extensions: ["dnd", "edit", "glyph", "wide"],
			checkbox: true,
			dnd: {
				focusOnClick: true,
				dragStart: function(node, data) { return true; },
				dragEnter: function(node, data) { return false; },
				dragDrop: function(node, data) { data.otherNode.copyTo(node, data.hitMode); }
			},
			glyph: glyph_opts,
			selectMode: 2,
			source: {url: "ajax-tree-taxonomy.json", debugDelay: 1000},
			toggleEffect: { effect: "drop", options: {direction: "left"}, duration: 400 },
			wide: {
				iconWidth: "1em",     // Adjust this if @fancy-icon-width != "16px"
				iconSpacing: "0.5em", // Adjust this if @fancy-icon-spacing != "3px"
				levelOfs: "1.5em"     // Adjust this if ul padding != "16px"
			},

			icon: function(event, data){
				// if( data.node.isFolder() ) {
				// 	return "glyphicon glyphicon-book";
				// }
			},
			lazyLoad: function(event, data) {
				data.result = {url: "ajax-sub2.json", debugDelay: 1000};
			}
		});

source: {url: "ajax-tree-taxonomy.json", debugDelay: 1000}这行代码中调用的是同目录下的 ajax-tree-taxonomy.json文件，

但是我们浏览的时候会报错：ERROR 404.3 Not Found for JSON file

解决方法： Okay, the problem is that IIS has no JSON-File type by default (MIME) so you have to set it up: To set this for the entire server: 1. Open properties for your server in your IIS Manager and go for MIME Types. 2. Use "New" and enter "JSON" as extension and "application/json" for MIME.

这个的意思就是说我们需要设置IIS中的MIMI类型，新建JSON application/json类型即可

 另外：浏览此类例子必须挂到IIS下，纯HTML不能读取文件