System.out.println("filename:" + gridFSDBFile.getFilename());
System.out.println("md5:" + gridFSDBFile.getMD5());
System.out.println("length:" + gridFSDBFile.getLength());
System.out.println("uploadDate:" + gridFSDBFile.getUploadDate());
System.out.println("--------------------------------------");
gridFSDBFile.writeTo(System.out);
上面的gridFSDBFile.writeTo(System.out);这句话的意思是什么?求大家指导