<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.13.0</version>
</dependency>
<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20210307</version>
</dependency>
<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.1</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jaxb</groupId>
    <artifactId>jaxb-runtime</artifactId>
    <version>2.3.1</version>
</dependency>

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import java.util.List;

@XmlRootElement(name = "data")
public class Data {
    private String name;
    private int age;
    private List<String> hobbies;

    // Getters and setters

    @XmlElement(name = "name")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @XmlElement(name = "age")
    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @XmlElement(name = "hobbies")
    public List<String> getHobbies() {
        return hobbies;
    }

    public void setHobbies(List<String> hobbies) {
        this.hobbies = hobbies;
    }
}

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;
import java.io.StringReader;

public class XMLParser {
    public static Data parseXML(String xml) throws Exception {
        JAXBContext context = JAXBContext.newInstance(Data.class);
        Unmarshaller unmarshaller = context.createUnmarshaller();
        StringReader reader = new StringReader(xml);
        Data data = (Data) unmarshaller.unmarshal(reader);
        return data;
    }
}

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class DataController {
    @PostMapping("/receive-xml")
    public ResponseEntity<String> receiveXML(@RequestBody String xml) {
        try {
            Data data = XMLParser.parseXML(xml);
            String json = JSONConverter.convertToJSON(data);
            return new ResponseEntity<>(json, HttpStatus.OK);
        } catch (Exception e) {
            return new ResponseEntity<>("Error processing XML", HttpStatus.BAD_REQUEST);
        }
    }
}

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.json.JSONObject;

public class JSONConverter {
    public static String convertToJSON(Data data) throws Exception {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
        return objectMapper.writeValueAsString(data);
    }
}

<data>
    <name>John</name>
    <age>30</age>
    <hobbies>
        <hobby>Reading</hobby>
        <hobby>Traveling</hobby>
        <hobby>Cooking</hobby>
    </hobbies>
</data>

{
  "name" : "John",
  "age" : 30,
  "hobbies" : [ "Reading", "Traveling", "Cooking" ]
}