Web文件上传——Base64方式

前端：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>简单的html5 File测试 for pic2base64</title>
<style>
</style>
<script>
    window.onload = function () {
        var input = document.getElementById("fielinput");
        var txshow = document.getElementById("txshow");
        if (typeof (FileReader) === 'undefined') {
            result.innerHTML = "抱歉，你的浏览器不支持 FileReader，请使用现代浏览器操作！";
            input.setAttribute('disabled', 'disabled');
        } else {
            input.addEventListener('change', readFile, false);
            txshow.onclick = function () { input.click(); }
        }
    }
    function readFile() {
        var file = this.files[0];
        //判断是否是图片类型
        /*if (!/image\/\w+/.test(file.type)) {
            alert("只能选择图片");
            return false;
        }*/
        var reader = new FileReader();
        reader.readAsDataURL(file);
        reader.onload = function (e) { 
            txshow.src = this.result; 
            document.getElementById("data").innerText=this.result.substring(this.result.indexOf(',')+1); 
        }
 
    
    }
 
</script>
</head>
<body>
 
<input type="file" id="fielinput" />
<img id="txshow" style="width:100px;height:100px;"/>
<br/>解析之后的base64数据：<br/>
<p id="data"></p>
</body>
</html>

后台：

//BASE64解码成File文件
        public UapAttachs toolsBase64ToFile(String base64, String fileName) {
            UapAttachs uapAttachs = null;
            if ( base64 != null && !base64.isEmpty()) {
                String FILEPATH;//文件路径
                String FILENAME;//文件名
                String FILEEXT = "";//文件后缀
                Long FILESIZE;//文件大小
                String emcrypt;//加密后的文件名
//                FILESIZE = (file.getSize()/1048576);
                FILESIZE = (base64.length()-(base64.length()/8L)*2L)/1048576;
                /*限制20MB大小以内*/
                if (FILESIZE > 20) {
                    return null;
                }
                /* 创建附件文件夹 */
                emcrypt = String.valueOf(System.currentTimeMillis());
                File attachment = new File("attachment");
                if (!attachment.exists()) {
                    attachment.mkdir();
                }
                /* 创建本地文件 */
                FILENAME = fileName!=null?fileName:"";                        
                if (FILENAME.indexOf(".") >= 0) {
                    FILEEXT = FILENAME.substring(FILENAME.lastIndexOf(".")+1,FILENAME.length());
                }
                File targetfile = new File(attachment.getAbsolutePath(),emcrypt+"_"+FILENAME);
                /* 解码base64到文件对象 */
                BufferedOutputStream bos = null;
                java.io.FileOutputStream fos = null;
                try {
                    byte[] bytes = Base64.getDecoder().decode(base64);                            
                    fos = new java.io.FileOutputStream(targetfile);
                    bos = new BufferedOutputStream(fos);
                    bos.write(bytes);
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    if (bos != null) {
                        try {
                            bos.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if (fos != null) {
                        try {
                            fos.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
                /* 返回文件对象信息 */
                FILEPATH = targetfile.getPath().replace("\\", "/");
                uapAttachs = new UapAttachs();
                if (targetfile.exists()) {
                    uapAttachs.setFilepath(FILEPATH);
                    uapAttachs.setFilename(FILENAME);
                    uapAttachs.setFileext(FILEEXT);
                    uapAttachs.setFilesize(FILESIZE);
                    uapAttachs.setAttachtype("");
                    uapAttachs.setCnname("");
                    uapAttachs.setObjvalue("");
                    uapAttachs.setObjid(3529L);
                }
            }
            return uapAttachs;
        }

 

posted @ 2020-03-04 09:33  情怀诗意  阅读(754)  评论(0)  编辑  收藏  举报