How to Handle XML Requests in Spring Boot Controllers with Message Converters

In previous Spring Boot tutorials we only covered handling HTML and JSON request/response formats. This article explains how to quickly wrap XML requests into objects in a controller and return XML responses.

Implementation principle: Message Converter

Spring Boot uses Spring MVC, which relies on the HttpMessageConverter interface to convert between HTTP request/response bodies and Java objects. The interface defines methods for type support, reading, and writing:

public interface HttpMessageConverter<T> {
    boolean canRead(Class<?> clazz, @Nullable MediaType mediaType);
    boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType);
    List<MediaType> getSupportedMediaTypes();
    T read(Class<? extends T> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException;
    void write(T t, @Nullable MediaType contentType, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException;
}

To support XML, Spring MVC provides MappingJackson2XmlHttpMessageConverter , which is automatically registered when the jackson-dataformat-xml dependency is present.

Extension implementation

Step 1: Introduce XML message converter

In a traditional Spring application you can add the converter manually:

@Configuration
public class MessageConverterConfig1 extends WebMvcConfigurerAdapter {
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        Jackson2ObjectMapperBuilder builder = Jackson2ObjectMapperBuilder.xml();
        builder.indentOutput(true);
        converters.add(new MappingJackson2XmlHttpMessageConverter(builder.build()));
    }
}

In a Spring Boot application you only need to add the following Maven dependency; Spring Boot will auto‑configure the converter:

<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
</dependency>

Step 2: Define the object‑XML relationship

Define a POJO that maps to the XML structure using Lombok and Jackson XML annotations:

@Data
@NoArgsConstructor
@AllArgsConstructor
@JacksonXmlRootElement(localName = "User")
public class User {
    @JacksonXmlProperty(localName = "name")
    private String name;

    @JacksonXmlProperty(localName = "age")
    private Integer age;
}

The annotations @Data, @NoArgsConstructor, and @AllArgsConstructor are from Lombok and generate getters, setters, and constructors. @JacksonXmlRootElement and @JacksonXmlProperty define how the fields map to XML elements.

Example XML that matches the User class:

<User>
    <name>aaaa</name>
    <age>10</age>
</User>

Step 3: Create an endpoint that receives and returns XML

Implement a controller method that consumes and produces XML:

@Controller
public class UserController {
    @PostMapping(value = "/user", consumes = MediaType.APPLICATION_XML_VALUE, produces = MediaType.APPLICATION_XML_VALUE)
    @ResponseBody
    public User create(@RequestBody User user) {
        user.setName("didispace.com : " + user.getName());
        user.setAge(user.getAge() + 100);
        return user;
    }
}

Start the Spring Boot application and use a tool like Postman to POST the example XML to /user. The service will return the processed XML with the modified name and age.