Question

Java平台如何判断用户上传的文件是否是图片

Answer 1

if(typeof FileReader != 'undefined'){
var file = document.getElementById("imageFile").files[0];
if((file.type).indexOf("image/")==-1){
swal("提示", "请上传图片!", "warning");
}
}else{
var fileName=document.getElementById("imageFile").value;
var suffixIndex=fileName.lastIndexOf(".");
var suffix=fileName.substring(suffixIndex+1).toUpperCase();
if(suffix!="BMP"&&suffix!="JPG"&&suffix!="JPEG"&&suffix!="PNG"&&suffix!="GIF"){
swal("提示", "请上传图片（格式BMP、JPG、JPEG、PNG、GIF等）!", "error");
}
}