Convert List of user-defined datatype to String and back into List Java

There are times when it is necessary to convert a list of user-defined objects to string and later on retrieve it as a list in its original form. Example: like storing it into a Redis cache.

How do we do that? 

ObjectMapper

Steps:

1. ObjectMapper objectMapper = new ObjectMapper();

First, initialize ObjectMapper.

2. List<YourClass> listObj ;

Create and initialize your list of user-defined object.

where, YourClass is a class having multiple variables.

Example -

class YourClass{

String abc;

String xyz;

}

3. String convertedStr = objectMapper.writeValueAsString(listObj);

This is the string conversion of the list.

4. listObj = objectMapper.readValue(convertedStr, new TypeReference<List<YourClass>>();

And we are back with your list object.