Java Dynamic Function Call

Question

I have a class

class JsonMap extends HashMap<String, Object> {}

I initialized an object like this

JsonMap jm = new JsonMap();

I am inserting data into it like this

jm.put("id", 4);
jm.put("message", "Hello");

but i want to do something easy like this with same effect.

jm.setId(4);
jm.setMessage("Hello");

Is this possibe without having to write methods setId and setMessage in JsonMap class?

function name is dynamic: first part is always 'set' and second part is dynamic value. this will go as key inside HashMap.

Can anyone show me how to achieve this, if it's possible?

i don't think that making something like `dynamic methods` or similar to javascript `prototype` is possible in java. — itwasntme, Aug 18 '15 at 19:45
My question is why would you do that? `jm.put("key","value")` is already very simple in writing — itwasntme, Aug 18 '15 at 19:56
U also can mess up a little bit and make something like this: http://pastebin.com/MtggQ9Ec but for me it just looks worse than standard `jm.put("key","val");` — itwasntme, Aug 18 '15 at 20:17

score 1 · Answer 1 · answered Aug 18 '15 at 20:08

What you are looking for is not possible as the language does not support this kind of feature, so at least you can stop looking for a built-in language feature. The alternative options you may want to look at:

professional JSON serializers (like Jackson)
JSONtoPOJO converters (many of these are available online)

nLee · Answer 2 · 2015-08-19T02:14:48.760

0

you would need to write methods to do this for you

public void setId(int id) {
    jm.put("id", id);
}

public void setMessage(String message) {
    jm.put("message", message);
}

edited Aug 19 '15 at 02:14

answered Aug 18 '15 at 19:45

nLee

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whole implementation would be case dependent and he would need to write method for every key he wants to include to JSON object – itwasntme Aug 18 '15 at 19:47
@syraz37 Java is a strongly typed language, not a scripting language. `jm.setId(4)` requires that the `setId(int)` method is defined in the class. – Andreas Aug 18 '15 at 19:58
1

@nLee Given his example, the `setId` method should take an `int`. – Andreas Aug 18 '15 at 20:01

score 0 · Answer 3 · answered Aug 18 '15 at 20:03

0

Java is a strongly typed language, not a scripting language, so no, it is not possible without having to write methods setId and setMessage in the JsonMap class.

answered Aug 18 '15 at 20:03

Andreas

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Java Dynamic Function Call

3 Answers3