Spring Boot Microservices Communication using WebClient with Example

Last Updated : 2 Jul, 2026

WebClient is a modern, reactive, and non-blocking HTTP client introduced in Spring Framework 5 as part of Spring WebFlux. It is used to send HTTP requests and communicate with applications and microservices. Unlike RestTemplate, which is synchronous and blocks the calling thread, WebClient supports both synchronous and asynchronous communication, making it the preferred choice for modern Spring Boot applications.

  • Supports both synchronous and asynchronous HTTP communication.
  • Provides a non-blocking and reactive programming model.
  • Recommended replacement for RestTemplate in modern Spring applications.

Syntax

class DefaultWebClient implements WebClient {
...
...
}

Steps to Use WebClient in Spring Boot

Follow these steps to configure a WebClient in Application.

Step 1: Add WebFlux Dependency

Add this dependency to the pom.xml file.

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

For Gradle:

Add the following entries to the build.gradle file.

dependencies {
compile 'org.springframework.boot:spring-boot-starter-webflux'
}

Step 2: Create a WebClient Bean

After adding the library create Bean for WebClient in the configuration file like below

@Bean
public WebClient webClient() {
return WebClient.builder()
.baseUrl(addressBaseUrl)
.build();
}

Step 3: Use WebClient in Service Layer

Now it's ready for use in the service class file. You can refer to the below code

Java 
@Service
public class EmployeeService {


    // More Code Here


    // -------------

    @Autowired
    private WebClient webClient;

    public EmployeeResponse getEmployeeById(int id) {
    
    
    // More Code Here
    
    // --------------


        // Using WebClient
        AddressResponse addressResponse = webClient.get().uri("/address/" + id).retrieve().bodyToMono(AddressResponse.class).block();
        employeeResponse.setAddressResponse(addressResponse);

        return employeeResponse;
    }

}

Let's understand the whole thing by developing two microservices and let's communicate with each other using WebClient.

Example Project

In this project, we are going to develop two Microservices

  • employee-service
  • address-service

Steps to Implements WebClient in Spring Boot Microservices

Follow these steps to implement WebClient between Employee Service and Address Service.

Developing Employee-Service

Step 1: Create a New Spring Boot Project

Create a Spring Boot project named employee-service using Spring Initializr.

 Add following dependencies:

  • Spring Boot DevTools
  • Spring Data JPA
  • MySQL Driver
  • Spring Web
Spring_initializr

Generate the project and run it in IntelliJ IDEA/Eclipse IDE by referring to the above article.

Step 2: Review the Generated pom.xml File.

The generated pom.xml file should contain the Following Dependency.

XML 
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="https://maven.apache.org/POM/4.0.0" 
         xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="https://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>3.0.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.gfg.employeaap</groupId>
    <artifactId>employee-service</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>employee-service</name>
    <description>Employee Service</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.modelmapper</groupId>
            <artifactId>modelmapper</artifactId>
            <version>3.1.1</version>
        </dependency>
    </dependencies>

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

</project>

Step 3: Create Schema in MySQL Workbench and Put Some Sample Data

Go to your MySQL Workbench and create a schema named gfgmicroservicesdemo and inside that create a table called employee and put some sample data as shown in the below image.

Spring-Boot-Microservices-1-(2)

Before moving to IntelliJ IDEA let's have a look at the complete project structure for our Microservices.

microservice-communication-4

Step 4: Configure Employee Service Properties

Now make the following changes in your application.properties file.

spring.datasource.url=jdbc:mysql://localhost:3306/gfgmicroservicesdemo
spring.datasource.username=put your username here
spring.datasource.password=put your password here
spring.application.name=employee-service
server.port=8080
# Set Your Context Path Here
server.servlet.context-path=/employee-service
addressservice.base.url=http://localhost:8081/address-service

Step 5: Create Your Entity/Model Class

Go to the src > main > java > entity and create a class Employee and put the below code. This is our model class.

Java 
package com.gfg.employeaap.entity;

import jakarta.persistence.*;

@Entity
@Table(name = "employee")
public class Employee {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id;

    @Column(name = "name")
    private String name;

    @Column(name = "email")
    private String email;

    @Column(name = "age")
    private String age;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

Step 6: Create Your Repository Interface

Go to the src > main > java > repository and create an interface EmployeeRepo and put the below code. This is our repository where we write code for all the database-related stuff.

Java 
package com.gfg.employeaap.repository;

import com.gfg.employeaap.entity.Employee;
import org.springframework.data.jpa.repository.JpaRepository;

@Repository
public interface EmployeeRepo extends JpaRepository<Employee, Integer> {

}

Note: Please refer to this article to know more about JpaRepository.

Step 7: Create an EmployeeResponse Class

Go to the src > main > java > response and create a class EmployeeResponse and put the below code.

Java 
package com.gfg.employeaap.response;

public class EmployeeResponse {

    private int id;
    private String name;
    private String email;
    private String age;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

Step 8: Create Your Service Class

Go to the src > main > java > service and create a class EmployeeService and put the below code. This is our service class where we write our business logic.

Java 
package com.gfg.employeaap.service;

import com.gfg.employeaap.entity.Employee;
import com.gfg.employeaap.repository.EmployeeRepo;
import com.gfg.employeaap.response.EmployeeResponse;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;

import java.util.Optional;

@Service
public class EmployeeService {

    @Autowired
    private EmployeeRepo employeeRepo;

    @Autowired
    private ModelMapper mapper;

    public EmployeeResponse getEmployeeById(int id) {
        Optional<Employee> employee = employeeRepo.findById(id);
        EmployeeResponse employeeResponse = mapper.map(employee, EmployeeResponse.class);
        return employeeResponse;
    }

}

Step 9: Create an Employee Controller

Go to the src > main > java > controller and create a class EmployeeController and put the below code. Here we are going to create an endpoint "/employees/{id}" to find an employee using id.

Java 
package com.gfg.employeaap.controller;

import com.gfg.employeaap.response.EmployeeResponse;
import com.gfg.employeaap.service.EmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class EmployeeController {

    @Autowired
    private EmployeeService employeeService;

    @GetMapping("/employees/{id}")
    private ResponseEntity<EmployeeResponse> getEmployeeDetails(@PathVariable("id") int id) {
        EmployeeResponse employee = employeeService.getEmployeeById(id);
        return ResponseEntity.status(HttpStatus.OK).body(employee);
    }

}

Step 10: Create a Configuration Class

Go to the src > main > java > configuration and create a class EmployeeConfig and put the below code.

Java 
package com.gfg.employeaap.configuration;

import com.gfg.employeaap.service.EmployeeService;
import org.modelmapper.ModelMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class EmployeeConfig {

    @Bean
    public ModelMapper modelMapperBean() {
        return new ModelMapper();
    }

}

Note: You may refer to these two articles

Step 11: Run Your Employee Microservice

To run your Employee Microservice src > main > java > EmployeeServiceApplication and click on the Run button. If everything goes well then you may see the following screen in your console.

context-path-2

Step 12: Test Your Endpoint in Postman

Now open Postman and hit the following URL

GET: http://localhost:8080/employee-service/employees/1

And you can see the following response

{
"id": 1,
"name": "Amiya",
"email": "ar@gmail",
"age": "25"
}

Developing Address-Service

Step 1: Create a New Spring Boot Project

Create a Spring Boot project named employee-service using Spring Initializr.

Add following dependencies:

  • Spring Boot DevTools
  • Spring Data JPA
  • MySQL Driver
  • Spring Web
Spring_initializr

Generate the project and run it in IntelliJ IDEA/Eclipse IDE by referring to the above article.

Step 2: Review the Generated pom.xml File.

The generated pom.xml file should contain the Following Dependency.

XML 
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="https://maven.apache.org/POM/4.0.0" xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="https://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>3.0.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.gfg.addressapp</groupId>
    <artifactId>address-service</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>address-service</name>
    <description>Address Service</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.modelmapper</groupId>
            <artifactId>modelmapper</artifactId>
            <version>3.1.1</version>
        </dependency>
    </dependencies>

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

</project>

Step 3: Create Schema in MySQL

Go to your MySQL Workbench and create a schema named gfgmicroservicesdemo and inside that create a table called address and put some sample data as shown in the below image. 

Note: In the Address table, employee_id is a foreign key so create it accordingly. We are going to perform a SQL join operation in our native SQL query. So create tables carefully.

Spring-Boot-Native-Query-1

Before moving to IntelliJ IDEA let's have a look at the complete project structure for our Microservices.

Spring-Boot-Native-Query-2

Step 4: Configure Address Service

Now make the following changes in your application.properties file.

spring.datasource.url=jdbc:mysql://localhost:3306/gfgmicroservicesdemo
spring.datasource.username=put your username here
spring.datasource.password=put your password here
spring.application.name=address-service
server.port=8081
server.servlet.context-path=/address-service

Step 5: Create Address Entity class

Go to the src > main > java > entity and create a class Address and put the below code. This is our model class.

Java 
package com.gfg.addressapp.entity;

import jakarta.persistence.*;

@Entity
@Table(name = "address")
public class Address {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id;

    @Column(name = "city")
    private String city;

    @Column(name = "state")
    private String state;

    public int getId() {
        return id;
    }

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

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }
}

Step 6: Create Your Repository Interface

Go to the src > main > java > repository and create an interface AddressRepo and put the below code. This is our repository where we write code for all the database-related stuff.

Java 
package com.gfg.addressapp.repository;

import com.gfg.addressapp.entity.Address;
import java.util.Optional;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

@Repository
public interface AddressRepo extends JpaRepository<Address, Integer> {

    @Query(
        nativeQuery = true,
        value
        = "SELECT ea.id, ea.city, ea.state FROM gfgmicroservicesdemo.address ea join gfgmicroservicesdemo.employee e on e.id = ea.employee_id where ea.employee_id=:employeeId")
       Optional<Address> findAddressByEmployeeId(@Param("employeeId") int employeeId);
}

Note: Please refer to this article to know more about JpaRepository.

Step 7: Create an AddressResponse Class

Go to the src > main > java > response and create a class AddressResponse and put the below code.

Java 
package com.gfg.addressapp.response;

public class AddressResponse {

    private int id;
    private String city;
    private String state;

    public int getId() {
        return id;
    }

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

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }
}

Step 8: Create Your Service Class

Go to the src > main > java > service and create a class AddressService and put the below code. This is our service class where we write our business logic.

Java 
package com.gfg.addressapp.service;

import com.gfg.addressapp.entity.Address;
import com.gfg.addressapp.repository.AddressRepo;
import com.gfg.addressapp.response.AddressResponse;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Optional;

@Service
public class AddressService {

    @Autowired
    private AddressRepo addressRepo;

    @Autowired
    private ModelMapper mapper;

    public AddressResponse findAddressByEmployeeId(int employeeId) {
        Optional<Address> addressByEmployeeId = addressRepo.findAddressByEmployeeId(employeeId);
        AddressResponse addressResponse = mapper.map(addressByEmployeeId, AddressResponse.class);
        return addressResponse;
    }

}

Step 9: Create an Address Controller

Go to the src > main > java > controller and create a class AddressController and put the below code. Here we are going to create an endpoint "/address/{employeeId}" to find the address using employee_id. Thats why we have created a foreign key in the Address table and we have performed the SQL join operation in the native query to get our desired result.

Java 
package com.gfg.addressapp.controller;

import com.gfg.addressapp.response.AddressResponse;
import com.gfg.addressapp.service.AddressService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class AddressController {

    @Autowired
    private AddressService addressService;

    @GetMapping("/address/{employeeId}")
    public ResponseEntity<AddressResponse> getAddressByEmployeeId(@PathVariable("employeeId") int employeeId) {
        AddressResponse addressResponse = addressService.findAddressByEmployeeId(employeeId);
        return ResponseEntity.status(HttpStatus.OK).body(addressResponse);
    }

}

Step 10: Create a Configuration Class

Go to the src > main > java > configuration and create a class AddressConfig and put the below code.

Java 
package com.gfg.addressapp.configuration;

import com.gfg.addressapp.service.AddressService;
import org.modelmapper.ModelMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AddressConfig {

    @Bean
    public ModelMapper modelMapperBean() {
        return new ModelMapper();
    }

}

Note: You may refer to these two articles

Step 11: Run Your Address Microservice

To run your Address Microservice src > main > java > AddressServiceApplication and click on the Run button. If everything goes well then you may see the following screen in your console. Please refer to the below image.

Spring-Boot-Native-Query-4

Step 12: Test Your Endpoint in Postman

Now open Postman and hit the following URL

GET: http://localhost:8081/address-service/address/2

And you can see the following response

{
"id": 1,
"city": "BLS",
"state": "Odisha"
}

Microservices Communication using WebClient

Now let's communicate between two microservices using RestTemplate. So we are going to get the address data by the employeeId of an employee and when we communicate we are going to get a response like the below. So let's implement it.

{
"id": 2,
"name": "Asish",
"email": "asis@gmail",
"age": "30",
"addressResponse": {
"id": 1,
"city": "BLS",
"state": "Odisha"
}
}

Step 1: Create an AddressResponse Class

Go to the employee-service > src > main > java > response and create a class AddressResponse and put the below code.

Java 
package com.gfg.employeaap.response;

public class AddressResponse {

    private int id;
    private String city;
    private String state;

    public int getId() {
        return id;
    }

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

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }
}

Step 2: Modify EmployeeResponse Class

Also, go to the employee-service > src > main > java > response > EmployeeResponse and modify the EmployeeResponse class as below.

Java 
package com.gfg.employeaap.response;

public class EmployeeResponse {

    private int id;
    private String name;
    private String email;
    private String age;
  
    // Add AddressResponse Here
    private AddressResponse addressResponse;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public AddressResponse getAddressResponse() {
        return addressResponse;
    }

    public void setAddressResponse(AddressResponse addressResponse) {
        this.addressResponse = addressResponse;
    }
}

Please refer to the below image.

microservice-communication-1

Step 3: Add webflux dependency to the pom.xml file

Add this dependency to the pom.xml file if present then skip.

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

Step 4: Modify EmployeeConfig Class

Go to the employee-service > src > main > java > configuration > EmployeeConfig and create the bean for WebClient.

Java 
package com.gfg.employeaap.configuration;

import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.reactive.function.client.WebClient;

@Configuration
public class EmployeeConfig {

    @Value("${addressservice.base.url}")
    private String addressBaseUrl;

    @Bean
    public ModelMapper modelMapperBean() {
        return new ModelMapper();
    }

    @Bean
    public WebClient webClient() {
        return WebClient.builder().baseUrl(addressBaseUrl).build();
    }

}

Step 5: Modify EmployeeService Class

Now go to the employee-service > src > main > java > service > EmployeeService and modify the EmployeeService class as below.

Java 
package com.gfg.employeaap.service;

import com.gfg.employeaap.entity.Employee;
import com.gfg.employeaap.repository.EmployeeRepo;
import com.gfg.employeaap.response.AddressResponse;
import com.gfg.employeaap.response.EmployeeResponse;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;

import java.util.Optional;

@Service
public class EmployeeService {

    @Autowired
    private EmployeeRepo employeeRepo;

    @Autowired
    private ModelMapper mapper;

    @Autowired
    private WebClient webClient;

    public EmployeeResponse getEmployeeById(int id) {

        Optional<Employee> employee = employeeRepo.findById(id);
        EmployeeResponse employeeResponse = mapper.map(employee, EmployeeResponse.class);

        // Using WebClient
        AddressResponse addressResponse = webClient.get().uri("/address/" + id).retrieve().bodyToMono(AddressResponse.class).block();
        employeeResponse.setAddressResponse(addressResponse);

        return employeeResponse;
    }

}

Step 6: Run Your Both Address and Employee Microservices

Now run your both Address and Employee Microservices. If everything goes well then you may see the following screen in your console. Please refer to the below image.

microservice-communication-2

Step 7: Test Your Endpoint in Postman

Now open Postman and hit the following URL

GET: http://localhost:8080/employee-service/employees/2

And you can see the following response Please refer to the below image.

microservice-communication-3

Comment

Explore