Jackson序列化和反序列化Json数据(2)

import java.io.File;
import java.io.IOException;
import java.io.StringWriter;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
 
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.node.ObjectNode;

public class JacksonObjectMapperExample {
 
    public static void main(String[] args) throws IOException {
       
        //read json file data to String
        byte[] jsonData = Files.readAllBytes(Paths.get("C:\\employee.txt"));
       
        //create ObjectMapper instance
        ObjectMapper objectMapper = new ObjectMapper();
       
        //convert json string to object
        Employee emp = objectMapper.readValue(jsonData, Employee.class);
       
        System.out.println("Employee Object\n"+emp);
       
        //convert Object to json string
        Employee emp1 = createEmployee();
        //configure Object mapper for pretty print
        objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
       
        //writing to console, can write to any output stream such as file
        StringWriter stringEmp = new StringWriter();
        objectMapper.writeValue(stringEmp, emp1);
        System.out.println("Employee JSON is\n"+stringEmp);
    }
   
    public static Employee createEmployee() {
 
        Employee emp = new Employee();
        emp.setId(100);
        emp.setName("David");
        emp.setPermanent(false);
        emp.setPhoneNumbers(new long[] { 123456, 987654 });
        emp.setRole("Manager");
 
        Address add = new Address();
        add.setCity("Bangalore");
        add.setStreet("BTM 1st Stage");
        add.setZipcode(560100);
        emp.setAddress(add);
 
        List<String> cities = new ArrayList<String>();
        cities.add("Los Angeles");
        cities.add("New York");
        emp.setCities(cities);
 
        Map<String, String> props = new HashMap<String, String>();
        props.put("salary", "1000 Rs");
        props.put("age", "28 years");
        emp.setProperties(props);
 
        return emp;
    }
 
}

结果如下：