Saturday 7 December 2019

Spring boot: @Field: Customize field names

@Field annotation is used to customize field names.

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

 @Field("employee_first_name")
 @Indexed(name = "emp_first_name", direction = IndexDirection.ASCENDING)
 private String firstName;

 @Field("employee_last_name")
 private String lastName;

 .......
 .......
}

For the above entity class, sample collection looks like below.
> db.employees.find().pretty()
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a4"),
 "employee_first_name" : "Phalgun",
 "employee_last_name" : "Garimella",
 "_class" : "com.sample.app.entity.Employee"
}
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a5"),
 "employee_first_name" : "Sankalp",
 "employee_last_name" : "Dubey",
 "_class" : "com.sample.app.entity.Employee"
}
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a6"),
 "employee_first_name" : "Arpan",
 "employee_last_name" : "Garimella",
 "_class" : "com.sample.app.entity.Employee"
}
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a7"),
 "employee_first_name" : "Phalgun",
 "employee_last_name" : "Dubey",
 "_class" : "com.sample.app.entity.Employee"
}

Find the below working application.

Employee.java    
package com.sample.app.entity;

import org.springframework.data.annotation.Id;
import org.springframework.data.annotation.Transient;
import org.springframework.data.mongodb.core.index.IndexDirection;
import org.springframework.data.mongodb.core.index.Indexed;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;

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

 @Field("employee_first_name")
 @Indexed(name = "emp_first_name", direction = IndexDirection.ASCENDING)
 private String firstName;

 @Field("employee_last_name")
 private String lastName;

 @Transient
 private String fullName;

 public Employee() {
 }

 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;
 }

 public String getFullName() {
  return this.getFirstName() + "," + this.getLastName();
 }

 public void setFullName(String fullName) {
  this.fullName = fullName;
 }

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

}

EmployeeRepository.java
package com.sample.app.repository;

import java.util.List;
import java.util.stream.Stream;

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

import com.sample.app.entity.Employee;

@Repository
public interface EmployeeRepository extends MongoRepository<Employee, String> {
 List<Employee> findByFirstName(String firstName);
 
 List<Employee> findByLastName(String lastName);
 
 List<Employee> findByFirstNameAndLastName(String firstName, String lastName);
 
 @Query("{'firstName' : ?0}")
 Stream<Employee> findAllByCustomQueryAndStream(String firstName);
}

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.Arrays;
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");
   Employee emp2 = new Employee("Sankalp", "Dubey");
   Employee emp3 = new Employee("Arpan", "Garimella");
   Employee emp4 = new Employee("Phalgun", "Dubey");

   empRepository.saveAll(Arrays.asList(emp1, emp2, emp3, emp4));

   List<Employee> emps = empRepository.findAll();
   emps.forEach(System.out::println);

  };
 }
}

Total project structure looks like below.


Run App.java, you can see below messages in console.
Employee [id=5d542018e4c7d8600175e5a4, firstName=Phalgun, lastName=Garimella, fullName=Phalgun,Garimella]
Employee [id=5d542018e4c7d8600175e5a5, firstName=Sankalp, lastName=Dubey, fullName=Sankalp,Dubey]
Employee [id=5d542018e4c7d8600175e5a6, firstName=Arpan, lastName=Garimella, fullName=Arpan,Garimella]
Employee [id=5d542018e4c7d8600175e5a7, firstName=Phalgun, lastName=Dubey, fullName=Phalgun,Dubey]

Query employees collection via mongo shell, you will get below response.

> db.employees.find().pretty()
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a4"),
 "employee_first_name" : "Phalgun",
 "employee_last_name" : "Garimella",
 "_class" : "com.sample.app.entity.Employee"
}
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a5"),
 "employee_first_name" : "Sankalp",
 "employee_last_name" : "Dubey",
 "_class" : "com.sample.app.entity.Employee"
}
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a6"),
 "employee_first_name" : "Arpan",
 "employee_last_name" : "Garimella",
 "_class" : "com.sample.app.entity.Employee"
}
{
 "_id" : ObjectId("5d542018e4c7d8600175e5a7"),
 "employee_first_name" : "Phalgun",
 "employee_last_name" : "Dubey",
 "_class" : "com.sample.app.entity.Employee"
}


Previous                                                    Next                                                    Home

No comments:

Post a Comment