如何在属性文件Groovy中设置空对象？

Question

I am trying to set a object value to null in properties file but it is always being returned as string. Here is the sample code along with the properties file.

File propertiesFile = new File('/opt/config.properties')
propertiesFile.withInputStream {
    properties.load(it)
}

    **config.properties**
    spotConfig = null

println properties.spotConfig

But when I am trying to print the above value, it is always returning string whereas I want it to print a null object. How can I do that in groovy? Any help appreciated!

Answer 1

There is no concept of explicitly assigning null in a properties file. The closest you can get is an empty string as you can read here .

spotConfig

Or you can simply not specify the key at all.

Answer 2

Properties keys and values are strings. So you can't get a null as value from a Properties instance containing that key.

In both of these cases, the value will be returned as a string:

x=
y=null

properties.get("x") will return "" , and properties.get("y") will return "null" (the literal string).

What you have to do is propbably remove the key from the file altogether (don't add a spotConfig key in the file) to get null