File節點是操作文件的節點
file文件的保存
拖拽 注入節點inject file節點（writes msg.payload to a file）和 debug節點到工作區，並連線
設置file節點的文件路徑
- windows如果不設置路徑，會保存在C:\Users\Administrator
- docker容器保存在根目錄下
此處文件名我選擇 放到data目錄下，因為docker容器啟動的時候我把/data目錄掛載到宿主機上了，方便查看文件
行為有三種，追加至文件 復寫文件 刪除文件
勾選上創建目錄，否則如果目錄和文件不存在，需要手動創建
例子：
[{"id":"898828bc.89b418","type":"inject","z":"6c70a17b.e110f","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":290,"y":300,"wires":[["1e951d4f.b4d6a3"]]},{"id":"1e951d4f.b4d6a3","type":"file","z":"6c70a17b.e110f","name":"save","filename":"/data/testtimestamp.txt","appendNewline":true,"createDir":true,"overwriteFile":"false","encoding":"none","x":450,"y":300,"wires":[["c27669f0.bef7e8"]]},{"id":"c27669f0.bef7e8","type":"debug","z":"6c70a17b.e110f","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":610,"y":300,"wires":[]}]
文件的讀取
文件的讀取和保存類似
把上面的file寫節點換成file讀節點(Reads the contents of a file...)
第一個注入節點inject只是啟動發送信號作用
debug區域顯示文件內容:
