Spring Boot MongoDB CRUD example with Maven

In this tutorial, we’re gonna build a Spring Boot Rest API example that use Spring Data MongoDB & Maven to make CRUD operations with MongoDB database. You’ll know:

• How to configure Spring Data to work with MongoDB Database
• How to define MongoDB Data Models and Repository interfaces
• Way to create Spring Rest Controller to process HTTP requests
• Way to use Spring Data MongoDB to interact with MongoDB Database

More Practice:
– Spring Boot, MongoDB, Reactive CRUD example
– Spring Boot + GraphQL + MongoDB example with Spring Data & graphql-java
– Spring Boot, MongoDB: JWT Authentication with Spring Security
– Spring Boot MongoDB Pagination example with Spring Data

Exception Handling:
– Spring Boot @ControllerAdvice & @ExceptionHandler example
– @RestControllerAdvice example in Spring Boot

Unit Test: Spring Boot Unit Test for Rest Controller
Documentation: Spring Boot Swagger 3 example
Caching: Spring Boot Redis Cache example
Validation: Spring Boot Validate Request Body

Fullstack:
– Angular 8 + Spring Boot + MongoDB example
– Angular 10 + Spring Boot + MongoDB example
– Angular 11 + Spring Boot + MongoDB example
– Angular 12 + Spring Boot + MongoDB example
– Angular 13 + Spring Boot + MongoDB example
– Angular 14 + Spring Boot + MongoDB example
– Angular 15 + Spring Boot + MongoDB example
– React + Spring Boot + MongoDB example
– Vue.js + Spring Boot + MongoDB example

Overview of Spring Boot MongoDB CRUD example

We will build a Spring Boot MongoDB Rest 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.

These are APIs that we need to provide:

– We make CRUD operations & finder methods using Spring Data MongoDB.
– Rest Controller will be created with the help of Spring Web MVC.

Technology

• Java 17 / 11 / 8
• Spring Boot 3 / 2 (with Spring Web MVC, Spring Data MongoDB)
• MongoDB
• Maven

Project Structure

• Tutorial data model class corresponds to entity and table tutorials.
• TutorialRepository is an interface that extends MongoRepository 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 Data MongoDB is in application.properties.
• pom.xml contains dependencies for Spring Boot Web MVC and Spring Data MongoDB.

Let’s implement this application right now.

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-web</artifactId>
</dependency>

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

Configure Spring Data MongoDB

Under src/main/resources folder, open application.properties and add following lines.

spring.data.mongodb.database=bezkoder_db
spring.data.mongodb.port=27017

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.data.mongodb.model;

import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

@Document(collection = "tutorials")
public class Tutorial {
  @Id
  private String id;

  private String title;
  private String description;
  private boolean published;

  public Tutorial() {

  }

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

  public String 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 + "]";
  }
}

@Document annotation helps us override the collection name by “tutorials”.

Create Repository Interface

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

repository/TutorialRepository.java

package com.bezkoder.spring.data.mongodb.repository;

import java.util.List;

import org.springframework.data.mongodb.repository.MongoRepository;

import com.bezkoder.spring.data.mongodb.model.Tutorial;

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

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

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

The implementation is plugged in by Spring Data MongoDB automatically.

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.data.mongodb.controller;

...
import com.bezkoder.spring.data.mongodb.model.Tutorial;
import com.bezkoder.spring.data.mongodb.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) {
    
  }

  @GetMapping("/tutorials/{id}")
  public ResponseEntity<Tutorial> getTutorialById(@PathVariable("id") String id) {
    
  }

  @PostMapping("/tutorials")
  public ResponseEntity<Tutorial> createTutorial(@RequestBody Tutorial tutorial) {
    
  }

  @PutMapping("/tutorials/{id}")
  public ResponseEntity<Tutorial> updateTutorial(@PathVariable("id") String id, @RequestBody Tutorial tutorial) {
    
  }

  @DeleteMapping("/tutorials/{id}")
  public ResponseEntity<HttpStatus> deleteTutorial(@PathVariable("id") String id) {
    
  }

  @DeleteMapping("/tutorials")
  public ResponseEntity<HttpStatus> deleteAllTutorials() {
    
  }

  @GetMapping("/tutorials/published")
  public ResponseEntity<List<Tutorial>> findByPublished() {
    
  }

}

– @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.

Now I will show you how to implement each controller’s CRUD methods.

Create Operation

We use @PostMapping annotation for handling POST HTTP requests.
A new Tutorial will be created by MongoRepository.save() method.

@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.INTERNAL_SERVER_ERROR);
  }
}

Retrieve Operations

We use @GetMapping annotation for handling GET HTTP requests, then Repository’s findAll(), findByTitleContaining(title), findByPublished() method to get the result.

• getAllTutorials(): returns List of Tutorials, if there is title parameter, it returns a List in that each Tutorial contains the title
• getTutorialById(): returns Tutorial by given id
• findByPublished(): return published Tutorials

@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") String id) {
  Optional<Tutorial> tutorialData = tutorialRepository.findById(id);

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

@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.INTERNAL_SERVER_ERROR);
  }
}

Update Operation

@PutMapping will help us handle PUT HTTP requests.
– updateTutorial() receives id and a Tutorial payload.
– from the id, we get the Tutorial from database using findById() method.
– then we use the payload and save() method for updating the Tutorial.

@PutMapping("/tutorials/{id}")
public ResponseEntity<Tutorial> updateTutorial(@PathVariable("id") String 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);
  }
}

Delete Operation

We use @DeleteMapping for DELETE HTTP requests.
There are 2 methods:

• deleteTutorial(): delete a Tutorial document with given id
• deleteAllTutorials(): remove all documents in tutorials collection

The operations is done with the help of MongoRepository’s deleteById() and deleteAll() method.

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

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

Run & Test

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

Create some Tutorials:

Check MongoDB database:

Update some Tutorials:

Check MongoDB database after updating:

Get all Tutorials:

Get a Tutorial by Id:

Find all published Tutorials:

Find all Tutorials which title contains ‘ring’:

Delete a Tutorial:

Check MongoDB database after deleting the Tutorial:

Delete all Tutorials:

You can use the Simple HTTP Client using Axios to check it.

Or: Simple HTTP Client using Fetch API

Conclusion

Today we’ve built a Rest CRUD API using Spring Boot, Spring Data MongoDB & Maven to create, retrieve, update, delete documents in MongoDB database.

We also see that MongoRepository supports a great way to make CRUD operations and custom finder methods without need of boilerplate code.

This project can be used in the following full-stack:
– Angular 8 + Spring Boot + MongoDB example
– Angular 10 + Spring Boot + MongoDB example
– Angular 11 + Spring Boot + MongoDB example
– Angular 12 + Spring Boot + MongoDB example
– Angular 13 + Spring Boot + MongoDB example
– Angular 14 + Spring Boot + MongoDB example
– Angular 15 + Spring Boot + MongoDB example
– React + Spring Boot + MongoDB example
– Vue.js + Spring Boot + MongoDB example

You may need to handle Exception with:
– Spring Boot @ControllerAdvice & @ExceptionHandler example
– @RestControllerAdvice example in Spring Boot

Or make pagination with structure of the response like this:

{
    "totalItems": 12,
    "tutorials": [...],
    "totalPages": 3,
    "currentPage": 1
}

With the tutorial: Spring Boot MongoDB Pagination example with Spring Data

Happy learning! See you again.

Further Reading

• Spring Boot, MongoDB: JWT Authentication with Spring Security
• Spring Data MongoDB Reference Documentation

Source Code

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

Reactive: Spring Boot, MongoDB, Reactive CRUD example
Documentation: Spring Boot + Swagger 3 example (with OpenAPI 3)
Caching: Spring Boot Redis Cache example
Validation: Spring Boot Validate Request Body