文件后缀名的获取并在<input>中显示！

 function checktype(obj) {

        var str=$(obj).val();
        var index=str.lastIndexOf('.');
        var len=str.length;
        var suffix=str.substring(index+1,len);
        alert(suffix);
//     /*   
//      ExpertsMntnEntity expertsMntnEntity=new ExpertsMntnEntity(); */
//      expertsMntnEntity.photosuffix=suffix;
    }

         <input id="photosuffix" name="photosuffix" value="${expertsMntnEntity.photosuffix}" style="width: 100px;height:20px;line-height:30px;>“

         <input type="file" id="content" name="content" value="${expertsMntnEntity.content}" style="width:148px;height:18px;" onchange="checktype(this)">

你这不是已经做到了吗? 你还缺少什么？

    function checktype(obj) {

        var str = $(obj).val();
        var index = str.lastIndexOf('.');
        var len = str.length;
        var suffix = str.substring(index + 1, len);
        document.getElementById('photosuffix').value=suffix////////////////
        alert(suffix);
        //     /*   
        //      ExpertsMntnEntity expertsMntnEntity=new ExpertsMntnEntity(); */
        //      expertsMntnEntity.photosuffix=suffix;
    }