Working with GridJs storage

Working With GridJs Storage

the general file process

After import a spread sheet file ,

GridJs will create a cache file with the specified uid in the Config.getFileCacheDirectory() folder ,

with the format of Aspose.Cells.SaveFormat.Xlsx ,

GridJs will also saves all shapes/images to a zip archive file in the Config.getPictureCacheDirectory() folder for later display shapes/images in the client UI.

and after every update operation in the client UI,

for example set cell value,set cell style,etc. ,

GridJs client side js will trigger controller action to do a UpdateCell operation.

In this action a save back to the cache file will occur during the UpdateCell method.

    @PostMapping("/UpdateCell")
    public ResponseEntity<String> updateCell(HttpServletRequest request) {
        String p = request.getParameter("p");
        String uid = request.getParameter("uid");
        GridJsWorkbook gwb = new GridJsWorkbook();
        String ret;
		try {
			ret = gwb.updateCell(p, uid);
			return new ResponseEntity<>(ret, HttpStatus.OK);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			return new ResponseEntity<>(gwb.errorJson(e.getMessage()), HttpStatus.OK);
		}

    }

where is the cache file actually

A. If we implement GridCacheForStream and set GridJsWorkbook.CacheImp. for example in the below code we can just put and get the cache file from “D:\temp”

Config.setFileCacheDirectory("D:\temp");
GridJsWorkbook.CacheImp=new LocalFileCache();
public class LocalFileCache extends GridCacheForStream {

	@Override
	public void saveStream(InputStream s, String uid) {
		// make sure the directory is exist
		String filepath = Paths.get(Config.getFileCacheDirectory(), "streamcache", uid.replace('/', '.')).toString();
		try (FileOutputStream fos = new FileOutputStream(filepath.toString())) {
			s.reset(); // Equivalent to s.Position = 0 in C#
			byte[] buffer = new byte[1024];
			int length;
			while ((length = s.read(buffer)) > 0) {
				fos.write(buffer, 0, length);
			}
			fos.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}

	@Override
	public InputStream loadStream(String uid) {
		String filepath = Paths.get(Config.getFileCacheDirectory(), "streamcache", uid.replace('/', '.')).toString();
		try {
			return new FileInputStream(filepath);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
			return null;
		}
	}

	@Override
	public boolean isExisted(String uid) {
		String filepath = Paths.get(Config.getFileCacheDirectory(), "streamcache", uid.replace('/', '.')).toString();
		return Files.exists(Paths.get(filepath));
	}

	@Override
	public String getFileUrl(String uid) {
		return "/GridJs2/GetFileUseCacheStream?id=" + uid;
	}

}
		...

B.If we do not set GridJsWorkbook.CacheImp,

GridJs will create and do save file within the folder of Config.getFileCacheDirectory() , which is the default cache directory which we can set.

how to get the updated result file

1. a specified uid for file

Make sure a specified maping correspondence between the file and the uid,

you can always get the same uid for a specifed file name,not from random generation.

For example just use the filename is ok.

//in controller  
 
     @GetMapping("/DetailStreamJsonWithUid")
    public void detailStreamJsonWithUid(@RequestParam String filename, @RequestParam String uid,HttpServletResponse response) {
       
           
        	Path filePath = Paths.get(listDir, filename);
            GridJsWorkbook wbj = new GridJsWorkbook();

            response.setContentType("application/json");
            response.setHeader("Content-Encoding", "gzip");
            try (GZIPOutputStream gzipOutputStream = new GZIPOutputStream(response.getOutputStream())) {
                wbj.importExcelFile(filePath.toString());
                wbj.jsonToStream(gzipOutputStream, filename);
            } catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
    }

2. sync with client UI operation

Actually for some client UI operation,

for example:

switch the acitve sheet to another,

change the image postion,

rotate/resize image,etc.

the UpdateCell action will not triggered.

Thus if we want to get the updated file just same as the client UI shows,

we need to do a merge operation before save action to sync those client UI operation.

//in the js
  function save() {
            if (!xs.buffer.isFinish()) {
              alert('updating is inprogress,please try later');
                return;
            }
            let datas = xs.datas;
            delete datas.history;
            delete datas.search;
            delete datas.images;
            delete datas.shapes;

        var jsondata = {
          sheetname: xs.sheet.data.name,
          actrow: xs.sheet.data.selector.ri,
          actcol: xs.sheet.data.selector.ci,
          datas: xs.getUpdateDatas(),
        };

        const data = {
          p: JSON.stringify(jsondata),
          uid: uniqueid,
        };
		....
		//go on to do ajax post to trigger controller action

//in controller action 
  GridJsWorkbook wb = new GridJsWorkbook();
  wb.mergeExcelFileFromJson(uid, p);
  //after merge do save to chache or to a stream or whaterver you want to save to ,here we just save to cache
  wb.saveToCacheWithFileName(uid,filename,password);

3. get the file url from cache

for example :in the download action,you can just get it from the cache directory by uid.

//in controller  

      String fileUrl = null;
			if (GridJsWorkbook.CacheImp != null) {
				fileUrl = GridJsWorkbook.CacheImp.getFileUrl(uid + "/" + filename);
			} else {
				fileUrl = "/GridJs2/GetFile?id=" + uid + "&filename=" + filename;
			}
			return ResponseEntity.ok("\""+fileUrl+"\"");

For more detail info ,you can check the example here: https://github.com/aspose-cells/Aspose.Cells.Grid-for-Java/tree/master/Examples_GridJs