weui上传多图片,压缩,base64编码的示例代码

<div class="weui-cell">
 <div class="weui-cell__bd">
  <div class="weui-uploader">
   <div class="weui-uploader__hd">
    <p class="weui-uploader__title">图片上传</p>
    <!--      <div class="weui-uploader__info">0/2</div>-->
   </div>
   <div class="weui-uploader__bd">
    <ul class="weui-uploader__files" id="uploaderFiles">
     <!--<li class="weui-uploader__file" style="background-image:url(/img/upload-btn.png)"></li>
     <li class="weui-uploader__file weui-uploader__file_status" style="background-image:url(/img/upload-btn.png)">
      <div class="weui-uploader__file-content">
       <i class="weui-icon-warn"></i>
      </div>
     </li>
     <li class="weui-uploader__file weui-uploader__file_status" style="background-image:url(/img/upload-btn.png)">
      <div class="weui-uploader__file-content">50%</div>
     </li>-->
    </ul>
    <div class="weui-uploader__input-box">
     <input id="uploaderInput" class="weui-uploader__input zjxfjs_file" type="file" accept="image/*" multiple="">
    </div>
   </div>
  </div>
 </div>
</div>

//文件上传js
var tmpl = '<li class="weui-uploader__file" style="background-image:url(#url#)"></li>',
 $gallery = $("#gallery"),
 $galleryImg = $("#galleryImg"),
 $uploaderInput = $("#uploaderInput"),
 $uploaderFiles = $("#uploaderFiles");
$uploaderInput.on("change", function(e) {
 var src, url = window.URL || window.webkitURL || window.mozURL,
  files = e.target.files;
 //这里获取到批量的file
 var fileNum =fileArr.length;
 for(var i = 0, len = files.length; i < len; ++i) {
  var file = files[i];
  if(fileNum + i + 1 > 5) {
   break;
  }
  // fileArr.push(file);
  if(url) {
   src = url.createObjectURL(file);
  } else {
   src = e.target.result;
  }
  var reader = new FileReader()
  reader.readAsDataURL(file)
  reader.onload = function(e) {
   var image = new Image() //新建一个img标签（还没嵌入DOM节点)
   image.src = e.target.result
   image.onload = function () {
    var canvas = document.createElement('canvas'),
     context = canvas.getContext('2d'),
     imageWidth = image.width / 5.5, //压缩后图片的大小
     imageHeight = image.height / 5.5;
    canvas.width = imageWidth;
    canvas.height = imageHeight;
    context.drawImage(image, 0, 0, imageWidth, imageHeight);

    var data = {
     base64: canvas.toDataURL('image/jpeg')
    }
    mui.ajax({
     url: "/file/uploadBase64",
     type: "POST",
     async: false,
     cache: false,
     processData: false,// 不处理发送的数据
     headers: {
      'Content-Type': 'application/json'
     },
     data: JSON.stringify(data),
     success: function(res){
      console.log(res)
      if (res.code==100){
       fileArr.push(res.data);
       //上传完成，前端页面显示
       $uploaderFiles.append($(tmpl.replace('#url#', canvas.toDataURL('image/jpeg'))));
      }else {
       weui.toast("出错了，请稍后再试", "forbidden");
      }
     },
     error:function () {
      weui.toast("出错了，请稍后再试", "forbidden");
     }
    });
   }
  }
 }
 checkPhotoSize();
});
//控制显示5张以内照片
function checkPhotoSize(){
 if(fileArr.length>4){
  $(".weui-uploader__input-box").hide();
 }else{
  $(".weui-uploader__input-box").show();
 }
}
var index; //第几张图片
$uploaderFiles.on("click", "li", function() {
 index = $(this).index();
 $galleryImg.attr("style", this.getAttribute("style"));
 $gallery.fadeIn(100);
});
$gallery.on("click", function() {
 $gallery.fadeOut(100);
});
//删除图片 删除图片的代码也贴出来。
$(".weui-gallery__del").click(function() {
 console.log('删除'+index);
 $uploaderFiles.find("li").eq(index).remove();
 fileArr.splice(index,1);
 checkPhotoSize();
});

 /**
  * 上传图片信息,base64字符串格式
  * @param map
  * @param model
  * @return
  */
 @PostMapping(value = "uploadBase64")
 @ResponseBody
 public Map<String, Object> uploadBase64Image(@RequestBody Map<String, Object> map) throws ParseException, IOException {
  Map<String, Object> imageMap = new HashMap<>();
  String base64 = map.get("base64").toString();
  MultipartFile file = BASE64DecodedMultipartFile.base64ToMultipart(base64);
  //获取文件保存路径
  String fileSavePath = globalConfService.getByKey(StaticConfigUtil.FILE_SAVE_PATH).getConfValue();
  String fileServerPath = globalConfService.getByKey(StaticConfigUtil.FILE_SERVER_PATH).getConfValue();
  fileSavePath = fileSavePath + DateUtil.formatDatetime("yyyy-MM-dd");
  fileServerPath = fileServerPath + DateUtil.formatDatetime("yyyy-MM-dd");
  if (!file.isEmpty()) {

   String fileName = file.getOriginalFilename();
   String ext=fileName.substring(fileName.lastIndexOf(".")+1);

   String imgName = "/"+UUID.randomUUID()+ "." +ext;

   InputStream in = null;
   OutputStream out = null;
   try {
    File serverFile = new File(fileSavePath+imgName);
    //判断文件父目录是否存在
    if(!serverFile.getParentFile().exists()){
     serverFile.getParentFile().mkdir();
    }
    if (!serverFile.exists()) {
     serverFile.createNewFile();
    }
    in = file.getInputStream();
    out = new FileOutputStream(serverFile);
    byte[] b = new byte[1024];
    int len = 0;
    while ((len = in.read(b))!=-1) {
     out.write(b, 0, len);
    }
    out.close();
    in.close();
    String serverPath = fileServerPath + imgName;
    return ResultUtil.successJson(serverPath);
   } catch (Exception e) {
    e.printStackTrace();
    return ResultUtil.errorJson(ErrorEnum.E_40001,e.getMessage());
   } finally {
    if (out != null) {
     out.close();
     out = null;
    }
    if (in != null) {
     in.close();
     in = null;
    }
   }
  } else {
   return ResultUtil.errorJson(ErrorEnum.E_90007);
  }
 }
/**
 * base64转MultipartFile文件
 *
 * @param base64
 * @return
 */
public static MultipartFile base64ToMultipart(String base64) {
 try {
  String[] baseStrs = base64.split(",");

  BASE64Decoder decoder = new BASE64Decoder();
  byte[] b = new byte[0];
  b = decoder.decodeBuffer(baseStrs[1]);

  for (int i = 0; i < b.length; ++i) {
   if (b[i] < 0) {
    b[i] += 256;
   }
  }

  return new BASE64DecodedMultipartFile(b, baseStrs[0]);
 } catch (IOException e) {
  e.printStackTrace();
  return null;
 }
}