I have many java classes, which can contain another class
public class SomeClass(){
private String key;
private String value;
private AnotherClass anotherClass;
}
public class AnotherClass(){
private String anotherkey;
private String anothervalue;
}
How can convert SomeClass to json in clojure? Already tried to use cheshire, clojure/data.json, but unsuccessfully
I have renamed your example classes to make it more concrete:
public class Person {
String name;
Address address;
}
public class Address {
String street;
String city;
}
Here is an outline of what to do. You simply define a conversion function for each class, and then compose them hierarchically:
(defn address->clj [address]
{:street (.-street address)
city (.-city address)})
(defn person->clj [person]
{:name (.-name person)
address (address->clj (.-address person))})
Consider some sample data (NOTE: constructor details omitted)
(def addr-1 (Address. "123 Main St" "Anytown"))
(def person-1 (Person. "Joe Smith" addr-1))
(someClass->clj person-1) ; Convert Java person-1 obj
You will get a Clojure map back that looks like:
{:name "Joe Smith"
:address {:street "123 Main St"
:city "Anytown"}}
Update
If you are working with a Java bean, please see also:
I am not sure, I understand your question correctly. If you would like to convert java bean to clojure data structure, you could simply use clojure bean API. Using postwalk, you could also convert all inner part too. Find an example in bellow
(let [ao (doto (AnotherClass.)
(.setAnotherkey "Ano")
(.setAnothervalue "Ano-value"))
o (doto (SomeClass.)
(.setKey "A")
(.setValue "A-value")
(.setAnotherClass ao))]
(->> (dissoc (bean o) :class)
(w/postwalk (fn [v]
(if (contains? #{AnotherClass SomeClass} (type v))
(dissoc (bean v) :class)
v)))))
;;Output {:anotherClass {:anotherkey "Ano", :anothervalue "Ano-value"}, :key "A", :value "A-value"}
With clojure.data.json you can extend writer protocol when necessary. E.g.:
(require 'clojure.data.json)
(extend-type java.util.UUID
clojure.data.json/JSONWriter
(-write [object ^PrintWriter out]
(.print out (str " something "))))
