Spring Boot Rest XML example – Web service with XML Response

bezkoder Spring

In this Spring Boot tutorial, I will show you a Restful Web service example in that Spring REST Controller can receive/consume XML Request Body and return XML Response instead of JSON. We also use Spring Data JPA to interact with database (MySQL/PostgreSQL).

More Practice:
– Documentation: Spring Boot + Swagger 3 example (with OpenAPI 3)
– Caching: Spring Boot Redis Cache example
– Spring Boot Thymeleaf CRUD example
– Spring Boot, Spring Data JPA – Building Rest CRUD API example
– Spring Boot + GraphQL + MySQL example

Associations:
– Spring Boot One To One example with JPA, Hibernate
– Spring Boot One To Many example with JPA, Hibernate
– Spring Boot Many to Many example with JPA, Hibernate

Deployment:
– Deploy Spring Boot App on AWS – Elastic Beanstalk
– Docker Compose: Spring Boot and MySQL example


Spring Boot XML REST Service

There are two ways to render XML responses:

  • Using Jackson XML extension (jackson-dataformat-xml) to render XML responses is easy, just add the following dependency:
    • <dependency>
  <groupId>com.fasterxml.jackson.dataformat</groupId>
  <artifactId>jackson-dataformat-xml</artifactId>
</dependency>
  • Using JAXB with dependency:
    • <dependency>
  <groupId>org.glassfish.jaxb</groupId>
  <artifactId>jaxb-runtime</artifactId>
</dependency>

    So XML can be rendered by annotating @XmlRootElement at the data model lass:

    @XmlRootElement
public class Tutorial {
  private String title;
  // .. getters and setters
}

In this example, we’re gonna use the first way.

Return XML Responses

You can tell Controller which methods should return XML Responses by using MediaType.APPLICATION_XML_VALUE as produces value of @RequestMapping annotation.

@RequestMapping(value="/tutorials/{id}", produces=MediaType.APPLICATION_XML_VALUE)
public ResponseEntity<Tutorial> getTutorialById(@PathVariable("id") long id) {
  // ...
}

In case you want to make all Controller methods return XML Reponses, you don’t have to mark each methods with produces=MediaType.APPLICATION_XML_VALUE. Just implement content negotiation by implementing WebMvcConfigurer and override configureContentNegotiation().

@Configuration
public class WebConfig implements WebMvcConfigurer {
  @Override
  public void configureContentNegotiation(final ContentNegotiationConfigurer configurer) {
    configurer.defaultContentType(MediaType.APPLICATION_XML);
  }
}

Overview of Spring Boot Rest XML example

We will build a Restful Web service that provides CRUD API for a Tutorial application in that:

  • Each Tutorial has id, title, description, published status.
  • Apis help to create, retrieve, update, delete Tutorials.
  • Apis also support custom finder methods such as find by published status or by title.
  • XML is the Content Type of HTTP Requests and Responses.

Here are the APIs:

Methods Urls Actions
POST /api/tutorials create new Tutorial
GET /api/tutorials retrieve all Tutorials
GET /api/tutorials/:id retrieve a Tutorial by :id
PUT /api/tutorials/:id update a Tutorial by :id
DELETE /api/tutorials/:id delete a Tutorial by :id
DELETE /api/tutorials delete all Tutorials
GET /api/tutorials/published find all published Tutorials
GET /api/tutorials?title=[keyword] find all Tutorials which title contains keyword

– We make CRUD operations & finder methods with Spring Data JPA’s JpaRepository.
– The database could be PostgreSQL or MySQL depending on the way we configure project dependency & datasource.

Technology

  • Java 8
  • Spring Boot 2.2.1 (with Spring Web MVC, Spring Data JPA)
  • PostgreSQL/MySQL
  • Maven 3.6.1
  • Jackson Dataformat XML 2.10.1

Project Structure

spring-boot-rest-xml-example-project-structure

– WebConfig implements WebMvcConfigurer. This is where we set the default content type.
– Tutorial data model class corresponds to entity and table tutorials.
– TutorialRepository is an interface that extends JpaRepository for CRUD methods and custom finder methods. It will be autowired in TutorialController.
– TutorialController is a RestController which has request mapping methods for RESTful requests such as: getAllTutorials, createTutorial, updateTutorial, deleteTutorial, findByPublished…
– Configuration for Spring Datasource, JPA & Hibernate in application.properties.
– pom.xml contains dependencies for Spring Boot, ackson Dataformat XML & MySQL/PostgreSQL.

Create & Setup Spring Boot project

Use Spring web tool or your development tool (Spring Tool Suite, Eclipse, Intellij) to create a Spring Boot project.

Then open pom.xml and add these dependencies:

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

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

We also need to add one more dependency.
– If you want to use MySQL:

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

– or PostgreSQL:

<dependency>
	<groupId>org.postgresql</groupId>
	<artifactId>postgresql</artifactId>
	<scope>runtime</scope>
</dependency>

Configure Spring Datasource, JPA, Hibernate

Under src/main/resources folder, open application.properties and write these lines.

– For MySQL:

spring.datasource.url= jdbc:mysql://localhost:3306/testdb?useSSL=false
spring.datasource.username= root
spring.datasource.password= 123456

spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.MySQL5InnoDBDialect

# Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto= update

– For PostgreSQL:

spring.datasource.url= jdbc:postgresql://localhost:5432/testdb
spring.datasource.username= postgres
spring.datasource.password= 123

spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation= true
spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.PostgreSQLDialect

# Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto= update
  • spring.datasource.username & spring.datasource.password properties are the same as your database installation.
  • Spring Boot uses Hibernate for JPA implementation, we configure MySQL5InnoDBDialect for MySQL or PostgreSQLDialect for PostgreSQL
  • spring.jpa.hibernate.ddl-auto is used for database initialization. We set the value to update value so that a table will be created in the database automatically corresponding to defined data model. Any change to the model will also trigger an update to the table. For production, this property should be validate.

Define Data Model

Our Data model is Tutorial with four fields: id, title, description, published.
In model package, we define Tutorial class.

model/Tutorial.java

package com.bezkoder.spring.datajpa.xml.model;

import javax.persistence.*;

@Entity
@Table(name = "tutorials")
public class Tutorial {

  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  private long id;

  @Column(name = "title")
  private String title;

  @Column(name = "description")
  private String description;

  @Column(name = "isPublished")
  private boolean published;

  public Tutorial() {

  }

  public Tutorial(String title, String description, boolean published) {
    this.title = title;
    this.description = description;
    this.published = published;
  }

  public long getId() {
    return id;
  }

  public String getTitle() {
    return title;
  }

  public void setTitle(String title) {
    this.title = title;
  }

  public String getDescription() {
    return description;
  }

  public void setDescription(String description) {
    this.description = description;
  }

  public boolean isPublished() {
    return published;
  }

  public void setPublished(boolean isPublished) {
    this.published = isPublished;
  }

  @Override
  public String toString() {
    return "Tutorial [id=" + id + ", title=" + title + ", desc=" + description + ", published=" + published + "]";
  }
}

– @Entity annotation indicates that the class is a persistent Java class.
– @Table annotation provides the table that maps this entity.
– @Id annotation is for the primary key.
– @GeneratedValue annotation is used to define generation strategy for the primary key. GenerationType.AUTO means Auto Increment field.
– @Column annotation is used to define the column in database that maps annotated field.

Create Repository Interface

Let’s create a repository to interact with Tutorials from the database.
In repository package, create TutorialRepository interface that extends JpaRepository.

repository/TutorialRepository.java

package com.bezkoder.spring.datajpa.xml.repository;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;

import com.bezkoder.spring.datajpa.xml.model.Tutorial;

public interface TutorialRepository extends JpaRepository<Tutorial, Long> {
  List<Tutorial> findByPublished(boolean published);
  List<Tutorial> findByTitleContaining(String title);
}

Now we can use JpaRepository’s methods: save(), findOne(), findById(), findAll(), count(), delete(), deleteById()… without implementing these methods.

We also define custom finder methods:
– findByPublished(): returns all Tutorials with published having value as input published.
– findByTitleContaining(): returns all Tutorials which title contains input title.

The implementation is plugged in by Spring Data JPA automatically.

More Derived queries at:
JPA Repository query example in Spring Boot

Custom query with @Query annotation:
Spring JPA @Query example: Custom query in Spring Boot

You can modify this Repository:
– to work with Pagination, the instruction can be found at:
Spring Boot Pagination & Filter example | Spring JPA, Pageable
– or to sort/order by multiple fields with the tutorial:
Spring Data JPA Sort/Order by multiple Columns | Spring Boot

You also find way to write Unit Test for this JPA Repository at:
Spring Boot Unit Test for JPA Repository with @DataJpaTest

Configure Content Negotiation for XML Type

Now we’re gonna implement content negotiation in our Spring Boot project.

config/WebConfig.java

package com.bezkoder.spring.datajpa.xml.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebConfig implements WebMvcConfigurer {
  @Override
  public void configureContentNegotiation(final ContentNegotiationConfigurer configurer) {
    configurer.defaultContentType(MediaType.APPLICATION_XML);
  }
}

Create Spring Rest APIs Controller

Finally, we create a controller that provides APIs for creating, retrieving, updating, deleting and finding Tutorials.

controller/TutorialController.java

package com.bezkoder.spring.datajpa.xml.controller;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import com.bezkoder.spring.datajpa.xml.model.Tutorial;
import com.bezkoder.spring.datajpa.xml.repository.TutorialRepository;

@CrossOrigin(origins = "http://localhost:8081")
@RestController
@RequestMapping("/api")
public class TutorialController {

  @Autowired
  TutorialRepository tutorialRepository;

  @GetMapping("/tutorials")
  public ResponseEntity<List<Tutorial>> getAllTutorials(@RequestParam(required = false) String title) {
    try {
      List<Tutorial> tutorials = new ArrayList<Tutorial>();

      if (title == null)
        tutorialRepository.findAll().forEach(tutorials::add);
      else
        tutorialRepository.findByTitleContaining(title).forEach(tutorials::add);

      if (tutorials.isEmpty()) {
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
      }

      return new ResponseEntity<>(tutorials, HttpStatus.OK);
    } catch (Exception e) {
      return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
    }
  }

  @GetMapping("/tutorials/{id}")
  public ResponseEntity<Tutorial> getTutorialById(@PathVariable("id") long id) {
    Optional<Tutorial> tutorialData = tutorialRepository.findById(id);

    if (tutorialData.isPresent()) {
      return new ResponseEntity<>(tutorialData.get(), HttpStatus.OK);
    } else {
      return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
  }

  @PostMapping("/tutorials")
  public ResponseEntity<Tutorial> createTutorial(@RequestBody Tutorial tutorial) {
    try {
      Tutorial _tutorial = tutorialRepository.save(new Tutorial(tutorial.getTitle(), tutorial.getDescription(), false));
      return new ResponseEntity<>(_tutorial, HttpStatus.CREATED);
    } catch (Exception e) {
      return new ResponseEntity<>(null, HttpStatus.EXPECTATION_FAILED);
    }
  }

  @PutMapping("/tutorials/{id}")
  public ResponseEntity<Tutorial> updateTutorial(@PathVariable("id") long id, @RequestBody Tutorial tutorial) {
    Optional<Tutorial> tutorialData = tutorialRepository.findById(id);

    if (tutorialData.isPresent()) {
      Tutorial _tutorial = tutorialData.get();
      _tutorial.setTitle(tutorial.getTitle());
      _tutorial.setDescription(tutorial.getDescription());
      _tutorial.setPublished(tutorial.isPublished());
      return new ResponseEntity<>(tutorialRepository.save(_tutorial), HttpStatus.OK);
    } else {
      return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
  }

  @DeleteMapping("/tutorials/{id}")
  public ResponseEntity<HttpStatus> deleteTutorial(@PathVariable("id") long id) {
    try {
      tutorialRepository.deleteById(id);
      return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    } catch (Exception e) {
      return new ResponseEntity<>(HttpStatus.EXPECTATION_FAILED);
    }
  }

  @DeleteMapping("/tutorials")
  public ResponseEntity<HttpStatus> deleteAllTutorials() {
    try {
      tutorialRepository.deleteAll();
      return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    } catch (Exception e) {
      return new ResponseEntity<>(HttpStatus.EXPECTATION_FAILED);
    }

  }

  @GetMapping("/tutorials/published")
  public ResponseEntity<List<Tutorial>> findByPublished() {
    try {
      List<Tutorial> tutorials = tutorialRepository.findByPublished(true);

      if (tutorials.isEmpty()) {
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
      }
      return new ResponseEntity<>(tutorials, HttpStatus.OK);
    } catch (Exception e) {
      return new ResponseEntity<>(HttpStatus.EXPECTATION_FAILED);
    }
  }

}

– @CrossOrigin is for configuring allowed origins.
– @RestController annotation is used to define a controller and to indicate that the return value of the methods should be be bound to the web response body.
– @RequestMapping("/api") declares that all Apis’ url in the controller will start with /api.
– We use @Autowired to inject TutorialRepository bean to local variable.

Run & Test

Run Spring Boot application with command: mvn spring-boot:run.

tutorials table will be automatically generated in Database.
If you check MySQL for example, you can see things like this:

mysql> describe tutorials;

+--------------+--------------+------+-----+---------+-------+
| Field        | Type         | Null | Key | Default | Extra |
+--------------+--------------+------+-----+---------+-------+
| id           | bigint(20)   | NO   | PRI | NULL    |       |
| description  | varchar(255) | YES  |     | NULL    |       |
| is_published | bit(1)       | YES  |     | NULL    |       |
| title        | varchar(255) | YES  |     | NULL    |       |
+--------------+--------------+------+-----+---------+-------+

Create Tutorials:

spring-boot-rest-xml-example-crud-api-create-item

mysql> select * from tutorials;

+----+-----------------------+--------------+--------+
| id | description           | is_published | title  |
+----+-----------------------+--------------+--------+
|  1 | Tut#1 Description     | 0            | Tut #1 |
|  2 | Tut#2 Description     | 0            | Tut #2 |
|  3 | Tut#3 Description     | 0            | Tut #3 |
|  4 | Description for Tut#4 | 0            | Tut #4 |
|  5 | Description for Tut#5 | 0            | Tut #5 |
+----+-----------------------+--------------+--------+

Get all Tutorials:

spring-boot-rest-xml-example-crud-api-retrieve-all-items

Get a Tutorial by Id:

spring-boot-rest-xml-example-crud-api-retrieve-item

Update some Tutorials:

spring-boot-rest-xml-example-crud-api-update-item

mysql> select * from tutorials;

+----+-----------------------+--------------+---------------------+
| id | description           | is_published | title               |
+----+-----------------------+--------------+---------------------+
|  1 | Tut#1 Desc            | 0            | bezkoder.com Tut #1 |
|  2 | Tut#2 Description     | 0            | Tut #2              |
|  3 | Tut#3 Desc            | 1            | bezkoder.com Tut #3 |
|  4 | Description for Tut#4 | 0            | Tut #4              |
|  5 | Tut#5 Desc            | 1            | bezkoder.com Tut #5 |
+----+-----------------------+--------------+---------------------+

Find all published Tutorials:

spring-boot-rest-xml-example-crud-api-find-items-published

Find all Tutorials which title contains ‘zkoder’:

spring-boot-rest-xml-example-crud-api-find-items-by-title

Delete a Tutorial:

spring-boot-rest-xml-example-crud-api-delete-item

mysql> select * from tutorials;

+----+-------------------+--------------+---------------------+
| id | description       | is_published | title               |
+----+-------------------+--------------+---------------------+
|  1 | Tut#1 Desc        | 0            | bezkoder.com Tut #1 |
|  2 | Tut#2 Description | 0            | Tut #2              |
|  3 | Tut#3 Desc        | 1            | bezkoder.com Tut #3 |
|  5 | Tut#5 Desc        | 1            | bezkoder.com Tut #5 |
+----+-------------------+--------------+---------------------+

Delete all Tutorials with API: DELETE http://localhost:8080/api/tutorials/

mysql> select * from tutorials;
Empty set (0.00 sec)

Conclusion

Today we’ve built a Spring Boot Rest XML example using Jackson XML extension to render XML and Spring Data JPA to interact with MySQL/PostgreSQL. You’ve known way to consume XML in Request Body and return XML Response.

If you want to learn more about Spring Boot Webservice that work with JSON data in Requests and Responses, please visit:
Spring Boot, Spring Data JPA – Building Rest CRUD API example

Custom query with @Query annotation:
Spring JPA @Query example: Custom query in Spring Boot

You can modify this Repository:
– to work with Pagination, the instruction can be found at:
Spring Boot Pagination & Filter example | Spring JPA, Pageable
– or to sort/order by multiple fields with the tutorial:
Spring Data JPA Sort/Order by multiple Columns | Spring Boot

You also find way to write Unit Test for this JPA Repository at:
Spring Boot Unit Test for JPA Repository with @DataJpaTest

Or Documentation: Spring Boot + Swagger 3 example (with OpenAPI 3)

Happy learning! See you again.

Further Reading

Associations:
– Spring Boot One To One example with JPA, Hibernate
– Spring Boot One To Many example with JPA, Hibernate
– Spring Boot Many to Many example with JPA, Hibernate

Deployment:
– Deploy Spring Boot App on AWS – Elastic Beanstalk
– Docker Compose: Spring Boot and MySQL example

Source Code

You can find the complete source code for this tutorial on Github.

More Derived queries at:
JPA Repository query example in Spring Boot

Caching: Spring Boot Redis Cache example

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