Spring boot: MongoDB: save or update the document

<S extends T> S save(S entity)

save method is used to create or update existing document.

save behaves differently if you pass a document with "_id" parameter.

If a document does not exist with the specified _id value, then save() method creates new document with specified fields in the document.

If a document exists with the specified _id value, then save() method performs an update, replacing all field in the existing record with the fields from the document.

Example

Employee emp1 = new Employee("Phalgun", "Garimella");

emp1 = empRepository.save(emp1);

List<Employee> emps = empRepository.findAll();

System.out.println("\nAll Employees");
for (Employee emp : emps) {
 System.out.println(emp);
}

emp1.setFirstName("ram");
emp1.setLastName("Gurram");
System.out.println("\nTrying to insert emp with same id again");

empRepository.save(emp1);

emps = empRepository.findAll();

System.out.println("\nAll Employees");
for (Employee emp : emps) {
 System.out.println(emp);
}

Find the below working application.

Employee.java

package com.sample.app.entity;

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

@Document("employees")
public class Employee {
 @Id
 private String id;

 private String firstName;

 private String lastName;

 public Employee(String firstName, String lastName) {
  this.firstName = firstName;
  this.lastName = lastName;
 }

 public String getId() {
  return id;
 }

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

 public String getFirstName() {
  return firstName;
 }

 public void setFirstName(String firstName) {
  this.firstName = firstName;
 }

 public String getLastName() {
  return lastName;
 }

 public void setLastName(String lastName) {
  this.lastName = lastName;
 }

 @Override
 public String toString() {
  StringBuilder builder = new StringBuilder();
  builder.append("Employee [id=").append(id).append(", firstName=").append(firstName).append(", lastName=")
    .append(lastName).append("]");
  return builder.toString();
 }

}

EmployeeRepository.java

package com.sample.app.repository;

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

import com.sample.app.entity.Employee;

@Repository
public interface EmployeeRepository extends MongoRepository<Employee, String> {

}

application.properties

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

logging.level.org.springframework.data=WARN

pom.xml

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>springDataMongo</groupId>
 <artifactId>springDataMongo</artifactId>
 <version>1</version>

 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>2.1.6.RELEASE</version>
 </parent>

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

App.java

package com.sample.app;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.data.mongodb.core.MongoOperations;
import org.springframework.data.mongodb.core.MongoTemplate;

import com.mongodb.MongoClient;
import com.sample.app.entity.Employee;
import com.sample.app.repository.EmployeeRepository;

@SpringBootApplication
public class App {
 @Value("${spring.data.mongodb.database}")
 private String database;

 @Value("${spring.data.mongodb.host}")
 private String host;

 @Value("${spring.data.mongodb.port}")
 private int port;

 @Autowired
 private EmployeeRepository empRepository;

 public static void main(String[] args) {

  SpringApplication.run(App.class, args);
 }

 public void dropPreviousData() {
  MongoClient mongoClient = new MongoClient(host, port);

  MongoOperations mongoOps = new MongoTemplate(mongoClient, database);

  mongoOps.dropCollection("employees");
 }

 @Bean
 public CommandLineRunner demo() {
  return (args) -> {

   dropPreviousData();

   Employee emp1 = new Employee("Phalgun", "Garimella");

   emp1 = empRepository.save(emp1);

   List<Employee> emps = empRepository.findAll();

   System.out.println("\nAll Employees");
   for (Employee emp : emps) {
    System.out.println(emp);
   }

   emp1.setFirstName("ram");
   emp1.setLastName("Gurram");
   System.out.println("\nTrying to insert emp with same id again");

   empRepository.save(emp1);

   emps = empRepository.findAll();

   System.out.println("\nAll Employees");
   for (Employee emp : emps) {
    System.out.println(emp);
   }

  };
 }
}

Total project structure looks like below.

Run App.java, you can see below messages in console.

All Employees
Employee [id=5d5237235d30d042e2726ae8, firstName=Phalgun, lastName=Garimella]

Trying to insert emp with same id again

All Employees
Employee [id=5d5237235d30d042e2726ae8, firstName=ram, lastName=Gurram]

You can download complete working application from this link.

Previous                                                    Next                                                    Home