<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>JS文件上传</title>
<script type="text/javascript" src="../js/jQuery.js"></script>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
#img {
display: block;
width: 9.98rem;
height: 6rem;
border: .01rem solid black;
}
#file {
display: block;
margin: -6rem 0 0 0;
opacity: 0;
width: 10rem;
height: 6rem;
}
#submit {
display: block;
width: 5rem;
height: 2rem;
margin: .5rem 2.5rem;
font-size: .45rem;
text-align: center;
line-height: 2rem;
}
</style>
</head>
<body>
<img id="img" src="" />
<input id="file" type="file" />
<input id="submit" type="button" value="提交文件" />
</body>
</html>
<script type="text/javascript">
// rem布局
$('html').css('font-size', $(window).width() / 10);
// 实例化文件输入框的读取对象
var fileReader = new FileReader();
var base64File = null;
// 当文件输入框读取到文件时
$('#file').on('change', function(){
// 获取文件列表
var fileList = $("#file")[0].files;
fileReader.onload = function(e){
// 获取扩展名
var extensionName = fileList[0].name.split('.');
extensionName = extensionName[extensionName.length -1];
// 获取文件的base64编码
var base64 = e.target.result;
// 将读取 文件放置到一个img标签
$('#img').attr('src', base64);
// 当文件加载完成后进行压缩
var img = $('#img')[0];
img.onload = function(){
// 将文件和文件扩展名拼接
base64File = cutDowmImg(img, 100).split(',')[1] + "." + extensionName;
// 将拼接后的字符串加密
base64File = encodeURIComponent(base64File);
}
}
fileReader.readAsDataURL(fileList[0]);
});
// 提交图片
$('#submit').on('click', function(){
console.log(base64File);
$.post("http://192.168.0.105/WebTest/Base64UploadServlet", {file: base64File}, function(e){
console.log(e);
})
});
// 压缩图片的方法
function cutDowmImg(img, width){
var canvas = document.createElement("canvas");
canvas.width = Math.min(img.width, width);
canvas.height = img.height*width/img.width;
var cxt = canvas.getContext("2d");
cxt.drawImage(img, 0, 0, img.width, img.height, 0, 0, canvas.width, canvas.height);
return canvas.toDataURL();
}
</script>
