springspring webresponse stream

Spring streaming response made easy

In this short article, we'll get into stream large size of data through stream as an alternative to the traditional endpoints.

Elattar Saad

Wed, 10th September 20252 min read

Product.java

@Entity
@Table(name = "products")
public class Product {
    @Id
    private Long id;
    private String name;
    private Double price;

    public Product() {
    }

    public Product(Long id, String name, Double price) {
        this.id = id;
        this.name = name;
        this.price = price;
    }

    public Long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public Double getPrice() {
        return price;
    }

    @Override
    public String toString() {
        return "Product[" +
                "id=" + id + ", " +
                "name=" + name + ", " +
                "price=" + price + ']';
    }
}

Product.java

@Entity
@Table(name = "products")
public class Product {
    @Id
    private Long id;
    private String name;
    private Double price;

    public Product() {
    }

    public Product(Long id, String name, Double price) {
        this.id = id;
        this.name = name;
        this.price = price;
    }

    public Long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public Double getPrice() {
        return price;
    }

    @Override
    public String toString() {
        return "Product[" +
                "id=" + id + ", " +
                "name=" + name + ", " +
                "price=" + price + ']';
    }
}

ProductRepository.java

import org.springframework.data.jpa.repository.JpaRepository;

public interface ProductRepository extends JpaRepository<Product, Long> {
}

ProductRepository.java

import org.springframework.data.jpa.repository.JpaRepository;

public interface ProductRepository extends JpaRepository<Product, Long> {
}

ProductController.java

@RestController
@RequestMapping("/products")
public class ProductController {

    private final ProductRepository productRepository;

    public ProductController(ProductRepository productRepository) {
        this.productRepository = productRepository;
    }

    @GetMapping
    public List<Product> getAll(){
       return productRepository.findAll();
    }
}

ProductController.java

@RestController
@RequestMapping("/products")
public class ProductController {

    private final ProductRepository productRepository;

    public ProductController(ProductRepository productRepository) {
        this.productRepository = productRepository;
    }

    @GetMapping
    public List<Product> getAll(){
       return productRepository.findAll();
    }
}

ProductController.java

@GetMapping("/stream")
    public StreamingResponseBody getAllStreamed(HttpServletResponse response){
       response.setContentType("text/event-stream");
       return outputStream -> {
           productRepository.findAll()
                    .forEach(product -> {
                        try

ProductController.java

@GetMapping("/stream")
    public StreamingResponseBody getAllStreamed(HttpServletResponse response){
       response.setContentType("text/event-stream");
       return outputStream -> {
           productRepository.findAll()
                    .forEach(product -> {

init.sql

-- Create table
CREATE TABLE IF NOT EXISTS products (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    price NUMERIC(10,2) NOT NULL
);

-- Insert 100,000 products
INSERT INTO products (name, price)
SELECT
    'Product ' || i,
    ROUND((RANDOM() * 1000)::numeric, 2)
FROM generate_series(1, 1000000) AS s(i);

init.sql

-- Create table
CREATE TABLE IF NOT EXISTS products (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    price NUMERIC(10,2) NOT NULL
);

-- Insert 100,000 products
INSERT INTO products (name, price)
SELECT
    'Product ' || i,
    ROUND((RANDOM() * 1000)::numeric, 2)
FROM generate_series(1, 1000000) AS s(i);

Spring streaming response made easy

Spring streaming response made easy

Saad Elattar

Keep reading

A gentle introduction to eBPF: Zero-Code Observability for Java

The End of Reactive? How Java Virtual Threads Are Making Complex Concurrency Simple Again

TechStack

Use case

Traditional endpoints

Streaming Response to the rescue

On another level

Resources

Streaming with JPA `Stream<T>`

Server-Sent Events (SSE) / Reactive

Spring streaming response made easy

Spring streaming response made easy

Saad Elattar

Keep reading

A gentle introduction to eBPF: Zero-Code Observability for Java

The End of Reactive? How Java Virtual Threads Are Making Complex Concurrency Simple Again

TechStack

Use case

Traditional endpoints

Streaming Response to the rescue

On another level

Resources

Streaming with JPA Stream<T>

Server-Sent Events (SSE) / Reactive

Streaming with JPA `Stream<T>`