MongoDB数据库不能修改了

[zfting]

public String updateSceneTypeImage(String typeId,String typeImage){
DBCollection dbCol = md.getUserCollection("scenetype");
BasicDBObject newDocument=new BasicDBObject().append("$set", new BasicDBObject("typeImage",typeImage));
dbCol.update(new BasicDBObject().append("typeId", typeId),newDocument,false,false);
return "{\"status\":200}";
}

这个是我的修改程序
我向修改type的图片信息，根据typeId来修改！！