Java中是否有参数树实现？

Question

Java program takes a long list of inputs(parameters), churns a bit and spits some output.

I need a way to organize these parameters in a sane way so in the input txt file I want to write them like this:

parameter1 = 12
parameter2 = 10
strategy1.parameter1 = "goofy"
strategy2.parameter4 = 100.0

Then read this txt file, turn it into a Java object I can pass around to objects when I instantiate them.

I now pyqtgraph has ParameterTree which is handy to use; is there something similar in Java? I am sure others must have had the same need so I don't want to reinvent the wheel.

(other tree structures would also be fine, of course, I just wanted something easy to read)

Answer 1

One way is to turn input.txt into input.json :

{
    "parameter1": 12,
    "parameter2": 10,
    "strategy1": {
        "parameter1": "goofy"
    },
    "strategy2": {
        "parameter4": 100.0
    }
}

Then use Jackson to deserialize input.json into one of these:

1. A Map<String, Object> instance, which you could navigate in depth to get all your parameters
2. An instance of some class of your own that mimics input.json 's structure, where your parameters would reside
3. A JsonNode instance that would be the root of the tree

(1) has the advantage that it's easy and you don't have to create any class to read the parameters, however you'd need to traverse the map, downcast the values you get from it, and you'd need to know the keys in advance (keys match json object's attribute names).

(2) has the advantage that everything would be correctly typed upon deserialization; no need to downcast anything, since every type would be a field of your own classes which represent the structure of the parameters. However, if the structure of your input.json file changed, you would need to change the structure of your classes as well.

(3) is the most flexible of all, and I believe it's the option that is closest to what you have in mind, nonetheless is the most tedious to work with, since it's too low-level. Please refer to this article for further details.