Here is a basic example of how to use the ObjectReader class in the com.fasterxml.jackson.databind package in Java:

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;
import com.fasterxml.jackson.databind.JsonNode;

import java.io.File;
import java.util.List;

public class Example {
    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        ObjectReader reader = mapper.readerFor(JsonNode.class);
        JsonNode root = reader.readValue(new File("example.json"));
        // do something with the root node
    }
}

In this example, we are importing the ObjectReader and ObjectMapper classes, as well as the JsonNode class from the com.fasterxml.jackson.databind package. We then create an instance of the ObjectMapper class, and use its readerFor method to get an ObjectReader instance for the JsonNode class.

We then use the readValue method of the ObjectReader instance to read the contents of a JSON file and return a JsonNode object representing the root of the JSON tree.

This is just a basic example of how to use the ObjectReader class, you can use it to configure the ObjectReader for custom deserialization, for example, you can use set methods to ignore properties, set date format, etc.