如何生成自定义Java对象的多个元组或字符串组合

Question

I'm trying to run a program that would load test my backend application. The program should generate all combinations of tuples of a particular class given the cardinality of each attribute of the class.

For example consider this class

public ClassA{
  String name;

  String id;

 String kind;
}

The use case is that the user will input cardinality of each attribute of this class and the output should List of Strings/Tuples of those values. For eg: User inputs name with cardinality 100 , kind with cardinality 10 and id with cardinality 1000 . Basically range of attributes generated will be name_0 to name_99 , kind_0 to kind_9 , id_0 to id_999 . So there will be a total of 1000*10*100 combinations.

This should generate

 < name_0, id_0, kind_0>
 < name_0, id_0, kind_1>
 < name_0, id_0, kind_2>
            .
            .
            .
            .
 < name_0, id_1, kind_0>
 < name_0, id_2, kind_0>
 < name_0, id_3, kind_0>
            .
            .
            .
            .
 < name_1, id_0, kind_0>
 < name_2, id_0, kind_0>
 < name_3, id_0, kind_0>
            .
            .
            .
            .

What is the best way to do this? From both an implementation and design perspective ? Any examples would definitely help

Answer 1

Something like the following:

IntStream.range(0, nameCount)
    .flatMap(n -> IntStream.range(0, idCount)
        .flatMap(i -> IntStream.range(0, kindCount)
            .map(k -> new ClassA("name_" + n, "id_" + i, "kind_" + k))))
            .collect(Collectors.toList());