How to create a Spring Boot REST service with XML output

In this article, I will be explaining how to create a Spring Boot REST service that produces an XML output.

Edit

 

Project Creation and Setup

 

Step 1 – Create a new Maven Project (Refer to this blog post). This should create a project as shown below:

maven-springboot-eclipse-project

Step 2 – Add the Spring Boot and Jackson dependency. So, your the pom.xml file should be similar to the following:

<project xmlns="http://maven.apache.org/POM/4.0.0"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">  <modelVersion>4.0.0</modelVersion>  <groupId>com.learnjava</groupId>  <artifactId>learnjava-springboot-xmloutput-demo</artifactId>  <version>0.0.1-SNAPSHOT</version>  <parent>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-parent</artifactId>    <version>2.1.2.RELEASE</version>  </parent>  <dependencies>    <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>    </dependencies>    <properties>        <java.version>1.8</java.version>    </properties></project>

Writing Code

Step 3 – Create a Book class as follows:

package com.learnjava.springbootxmldemo.book;public class Book {  private int id;  private String name;  private String author;        //constructor, getters and setters}

This class represents a Book. It has fields corresponding to id, name and author.

 

Step 4 – Create a BookController class as follows:

package com.learnjava.springbootxmldemo.book;import java.util.ArrayList;import java.util.List;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RestController;@RestControllerpublic class BookController {   @GetMapping(value="/books",produces = { "application/xml", "text/xml" })    public List<Book> getAllBooks(){      //Returns hardcoded data, a real world application would return from the database      List<Book> books = new ArrayList<Book>();      books.add(new Book(1,"Emma", "Jane Austen"));      books.add(new Book(2,"Harry Potter", "JK Rowling"));      books.add(new Book(3,"The Partner", "John Grisham"));      return books;    }       @GetMapping(value="/book", produces = { "application/xml", "text/xml" })    public Book getBook(){      //Returns hardcoded data, a real world application would return from the database      return new Book(1,"Emma", "Jane Austen");    } }

This is a Controller class and specifies the methods that handle client requests. . It has the RestController annotation specified.

It includes the following methods:

getAllBooks

  • The GetMapping annotation is specified on this method. This specifies that this method maps to the /books URL and that it produces an XML output
  • The method simply creates a List of type Book, adds some Book objects to it and returns it. A real-world application will typically query a database and obtain Book objects.

getBook

  • Like getAllBooks, this method has the GetMapping annotation
  • It returns a single Book object

Step 5 – Create a Main class as follows:

package com.learnjava.springbootxmldemo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublic class Main {    public static void main(String[] args) {          SpringApplication.run(Main.class, args);      }}

This is the starting point of our Spring Boot application as explained here.

Edit

Running the application

Step 6 – Run Main.java as a Java application as shown below:

running-spring-boot-main

Step 7 – Open a browser window. Type http://localhost:8080/books/ . This displays the following XML output:

xm-output

You can download the source code for this project via the Github repository here.

Conclusion

So, in this article, we saw how to create a Spring Boot application that produces an XML output.

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