Check Exists Entity with CrudRepository Interface in Spring Boot MongoDB

Create a database with the name is SpringDataMongoDBRepository. This database have a collection: Product collection.

/* Create SpringDataMongoDBRepository database */
use SpringDataMongoDBRepository

/* Create Product collection */
db.createCollection('product');

/* Dumping data for `product` collection */
db.getCollection('product').insertOne({
	"name" : "Mobile 1",
    "price" : 45.0,
    "quantity" : 4.0,
    "status" : true,
    "date" : ISODate("2016-10-20T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa45711668"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 1"
    },
    "colors" : [
        "red",
        "green",
        "blue"
    ]
});

db.getCollection('product').insertOne({
	"name" : "Mobile 2",
    "price" : 12.0,
    "quantity" : 7.0,
    "status" : true,
    "date" : ISODate("2017-11-14T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa45711668"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 2"
    },
    "colors" : [
        "yellow",
        "green"
    ]
});

db.getCollection('product').insertOne({
	"name" : "Mobile 3",
    "price" : 28.0,
    "quantity" : 8.0,
    "status" : true,
    "date" : ISODate("2017-11-20T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa45711668"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 3"
    },
    "colors" : [
        "black",
        "blue"
    ]
});

db.getCollection('product').insertOne({
	"name" : "Laptop 1",
    "price" : 39.0,
    "quantity" : 12.0,
    "status" : false,
    "date" : ISODate("2017-12-26T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa45711669"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 1"
    },
    "colors" : [
        "blue"
    ]
});

db.getCollection('product').insertOne({
	"name" : "Laptop 2",
    "price" : 86.0,
    "quantity" : 23.0,
    "status" : true,
    "date" : ISODate("2017-03-11T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa45711669"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 1"
    },
    "colors" : [
        "blue",
        "yellow"
    ]
});

db.getCollection('product').insertOne({
	"name" : "Tivi 1",
    "price" : 22.0,
    "quantity" : 7.0,
    "status" : true,
    "date" : ISODate("2017-06-26T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa4571166a"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 1"
    },
    "colors" : [
        "blue",
        "white",
        "black"
    ]
});

db.getCollection('product').insertOne({
	"name" : "Tivi 2",
    "price" : 86.0,
    "quantity" : 23.0,
    "status" : false,
    "date" : ISODate("2017-09-24T00:00:00.000Z"),
    "categoryId" : ObjectId("5a30de130867edfa4571166a"),
    "brand" : {
        "_id" : new ObjectId(),
        "name" : "brand 3"
    },
    "colors" : [
        "red",
        "green"
    ]
});

On the Spring Tool Suite, create a Spring Boot project

Enter Project Information:

Name: SpringBootMongoDB
Group: com.example.demo
Artifact: SpringBootMongoDB
Description: Learn Spring Boot MongoDB with Real Apps
Package: com.example.demo

Select the technologies and libraries to be used:

Spring Data MongoDB
Spring Boot Devtools

Click Next button to show Project’s Information

Click Finish button to finish create Spring Boot project

<?xml version="1.0" encoding="UTF-8"?>
<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>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.4.2</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>SpringBootMongoDB</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>SpringBootMongoDB</name>
	<description>Learn Spring Boot MongoDB with Real Apps</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>

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

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>

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

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

Open application.properties file in src/main/resources folder and add configurations connect to database as below:

spring.data.mongodb.database=SpringDataMongoDBRepository
spring.data.mongodb.port=27017
spring.data.mongodb.host=localhost

Create new package named com.example.demo.entities. In this package, create new Java classes as below:

In com.example.demo.entities package, create new class named Brand.java as below:

package com.example.demo.entities;

public class Brand {

	private String id;
	private String name;

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

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

	public Brand(String id, String name) {
		this.id = id;
		this.name = name;
	}

	public Brand() {
	}

}

In com.example.demo.entities package, create new class named Product.java as below:

package com.example.demo.entities;

import java.util.Date;
import java.util.List;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;

@Document(collection = "product")
public class Product {

	@Id
	private String id;
	private String name;
	private double price;
	private int quantity;
	private boolean status;
	private Date date;
	private String categoryId;
	private Brand brand;
	private List<String> colors;

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

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

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

	public void setQuantity(int quantity) {
		this.quantity = quantity;
	}

	public boolean isStatus() {
		return status;
	}

	public void setStatus(boolean status) {
		this.status = status;
	}

	public Date getDate() {
		return date;
	}

	public void setDate(Date date) {
		this.date = date;
	}

	public String getCategoryId() {
		return categoryId;
	}

	public void setCategoryId(String categoryId) {
		this.categoryId = categoryId;
	}

	public Brand getBrand() {
		return brand;
	}

	public void setBrand(Brand brand) {
		this.brand = brand;
	}

	public List<String> getColors() {
		return colors;
	}

	public void setColors(List<String> colors) {
		this.colors = colors;
	}

}

Create new package named com.example.demo.repositories. In this package, create new interface named ProductRepository.java implement from CrudRepository interface of Spring Framework as below:

package com.example.demo.repositories;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import com.example.demo.entities.Product;

@Repository("productRepository")
public interface ProductRepository extends CrudRepository<Product, String> {

}

Create new package named com.example.demo.services. In this package create new interface named ProductService.java as below:

package com.example.demo.services;

public interface ProductService {

	public boolean exists(String id);

}

In com.example.demo.services package, create new java class named ProductServiceImpl.java implement from ProductService interface

package com.example.demo.services;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.example.demo.repositories.ProductRepository;

@Service("productService")
public class ProductServiceImpl implements ProductService {

	@Autowired
	private ProductRepository productRepository;

	@Override
	public boolean exists(String id) {
		return productRepository.existsById(id);
	}

}

Create new package named com.example.demo.configurations, create new Java class named MongoDBConfigurations.java as below:

package com.example.demo.configurations;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.data.mongodb.MongoDatabaseFactory;
import org.springframework.data.mongodb.core.convert.DbRefResolver;
import org.springframework.data.mongodb.core.convert.DefaultDbRefResolver;
import org.springframework.data.mongodb.core.convert.DefaultMongoTypeMapper;
import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import com.example.demo.services.ProductService;
import com.example.demo.services.ProductServiceImpl;

@Configuration
@EnableTransactionManagement
@EnableMongoRepositories(basePackages = { "com.example.demo.repositories" })
@ComponentScan("com.example.demo")
@PropertySource("classpath:application.properties")
public class MongoDBConfigurations {

	@Autowired
	private MongoDatabaseFactory mongoDatabaseFactory;

	@Autowired
	private MongoMappingContext mongoMappingContext;

	@Bean
	public MappingMongoConverter mappingMongoConverter() {
		DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDatabaseFactory);
		MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, mongoMappingContext);
		converter.setTypeMapper(new DefaultMongoTypeMapper(null));
		return converter;
	}

	@Bean
	public ProductService productService() {
		return new ProductServiceImpl();
	}

}

Create new package named com.example.demo.demo, create new Java class named Demo.java as below:

package com.example.demo.main;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;

import com.example.demo.configurations.MongoDBConfigurations;
import com.example.demo.services.ProductService;

public class Demo {

	public static void main(String[] args) {
		try {
			AbstractApplicationContext context = new AnnotationConfigApplicationContext(MongoDBConfigurations.class);
			ProductService productService = context.getBean(ProductService.class);

			boolean result = productService.exists("5a586149cfad614dc07d93b9");
			System.out.println("Check Exists: " + result);

			context.close();
		} catch (Exception e) {
			System.err.println(e.getMessage());
		}
	}

}

Check Exists: true

Check Exists Entity with CrudRepository Interface in Spring Boot MongoDB

Create Database

Create Spring Boot Project

Configure pom.xml

Database Configuration

Entities Class

Brand Class

Product Class

ProductRepository Interface

ProductService Interface

ProductServiceImpl Class

Configuration Class

Run Application

Project Structure

Output