spring boot + http requests

different files.java

HibernateApplication.java:

package site.sunmeat.hibernate;

import java.awt.Desktop;
import java.net.URI;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.event.ApplicationReadyEvent;
import org.springframework.context.annotation.Bean;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.client.WebClient;

@SpringBootApplication
public class HibernateApplication {
	public static void main(String[] args) {
		SpringApplication.run(HibernateApplication.class, args);
	}
	
	@Bean
    WebClient.Builder webClientBuilder() {
        return WebClient.builder(); // спрінгу буде потрібен білдер для веб-клієнта, без цього не створиться об'єкт і запити не відправляться
    }
}

@Component
class BrowserLauncher {
    @EventListener(ApplicationReadyEvent.class)
    public void launchBrowser() {
        System.setProperty("java.awt.headless", "false");
        Desktop desktop = Desktop.getDesktop();
        try {
            desktop.browse(new URI("http://localhost:8080"));
        } catch (Exception e) {

        }
    }
} 

===================================================================================================================
  
WebController.java:

package site.sunmeat.hibernate;

import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.core.publisher.Mono;
import java.util.*;

@Controller
public class WebController {
    private final WebClient webClient;

    public WebController(WebClient.Builder webClientBuilder) {
        this.webClient = webClientBuilder.build();
    }

    @GetMapping("/")
    public String index() {
        return "index";
    }

    @GetMapping("/api/text")
    @ResponseBody
    public Mono<Map<String, String>> getText() {
        String url = "http://sunmeat.atwebpages.com/volley/plain.txt";
        return webClient.get()
                .uri(url)
                .retrieve()
                .bodyToMono(String.class)
                .map(content -> Map.of(
                        "title", "Текстовий файл (plain.txt)",
                        "content", content
                ))
                .onErrorReturn(Map.of("title", "Помилка", "content", "Не вдалося завантажити текстовий файл"));
    }

    @GetMapping("/api/image")
    @ResponseBody
    public Mono<Map<String, String>> getImage() {
        String url = "https://raw.githubusercontent.com/sunmeat/gallery/main/MyApplication/cats/cat (1).jpg";
        return webClient.get()
                .uri(url)
                .retrieve()
                .bodyToMono(byte[].class)
                .map(bytes -> Map.of(
                        "title", "Зображення котика",
                        "imageBase64", "data:image/jpeg;base64," + Base64.getEncoder().encodeToString(bytes)
                ))
                .onErrorReturn(Map.of("title", "Помилка", "content", "Не вдалося завантажити зображення"));
    }

    @GetMapping("/api/json-object")
    @ResponseBody
    public Mono<Map<String, String>> getJsonObject() {
        String url = "http://sunmeat.atwebpages.com/volley/alex.json";
        return webClient.get()
                .uri(url)
                .retrieve()
                .bodyToMono(String.class)
                .map(json -> Map.of(
                        "title", "JSON-об’єкт (alex.json)",
                        "content", json
                ))
                .onErrorReturn(Map.of("title", "Помилка", "content", "Не вдалося завантажити JSON"));
    }

    @GetMapping("/api/json-array")
    @ResponseBody
    public Mono<Map<String, String>> getJsonArray() {
        String url = "http://sunmeat.atwebpages.com/volley/array.json";
        return webClient.get()
                .uri(url)
                .retrieve()
                .bodyToMono(String.class)
                .map(json -> Map.of(
                        "title", "JSON-масив (array.json)",
                        "content", json
                ))
                .onErrorReturn(Map.of("title", "Помилка", "content", "Не вдалося завантажити масив"));
    }

    @GetMapping("/api/post")
    @ResponseBody
    public Mono<Map<String, String>> sendPost() {
        String url = "http://sunmeat.atwebpages.com/volley/script.php";
        return webClient.post()
                .uri(url)
                .contentType(MediaType.APPLICATION_FORM_URLENCODED)
                .bodyValue("first=10&second=15")
                .retrieve()
                .bodyToMono(String.class)
                .map(response -> Map.of(
                        "title", "Відповідь від POST-запиту",
                        "content", response
                ))
                .onErrorReturn(Map.of("title", "Помилка", "content", "Сервер не відповів"));
    }
}

===================================================================================================================
  
static / style.css:

@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:wght@500;600;700&family=Playfair+Display:wght@700;900&display=swap');

:root {
    --bg: #0F0A05;
    --surface: #3D2B1F;
    --coffee: #6F4E37;
    --coffee-dark: #5D4037;
    --gold: #D4AF37;
    --gold-light: #E8C56A;
    --cream: #D7CCC8;
    --text: #EFEBE9;
    --shadow: 0 12px 32px rgba(0,0,0,0.45);
    --transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

html{scroll-behavior:smooth}

body{
    font-family:'Cormorant Garamond',serif;
    background:var(--bg);
    color:var(--text);
    min-height:100vh;
    padding:60px 20px;
    line-height:1.8;
    background:linear-gradient(to bottom,#0F0A05,#1A120B)
}

h1{
    font-family:'Playfair Display',serif;
    font-size:clamp(3rem,9vw,6.5rem);
    text-align:center;
    color:var(--gold);
    margin:80px 0 100px;
    letter-spacing:2px;
    text-shadow:0 4px 12px rgba(0,0,0,0.6);
    position:relative
}

h1::after{
    content:'';
    position:absolute;
    left:50%;bottom:-30px;
    transform:translateX(-50%);
    width:220px;
    height:4px;
    background:linear-gradient(90deg,transparent,var(--gold),var(--gold-light),var(--gold),transparent);
    border-radius:2px;
    box-shadow:0 0 12px rgba(212,175,55,0.6)
}

.container{max-width:1360px;margin:0 auto;padding:0 20px}

.buttons{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(340px,1fr));
    gap:40px;
    margin:80px 0
}

button{
    position:relative;
    background:var(--coffee);
    color:var(--cream);
    border:none;
    padding:38px 24px;
    font-family:inherit;
    font-size:1.58em;
    font-weight:600;
    letter-spacing:2.5px;
    text-transform:uppercase;
    border-radius:18px;
    cursor:pointer;
    overflow:hidden;
    box-shadow:var(--shadow);
    transition:var(--transition);
    transform:translateZ(0);
    will-change:transform
}

button::before{
    content:'';
    position:absolute;
    inset:0;
    background:radial-gradient(circle at var(--x,50%) var(--y,50%), 
                rgba(212,175,55,0.35) 0%,
                rgba(212,175,55,0.15) 40%,
                transparent 70%);
    opacity:0;
    transition:opacity .5s cubic-bezier(0.4,0,0.2,1);
    pointer-events:none
}

button:hover::before{
    opacity:1
}

button:hover{
    transform:translateY(-12px);
    box-shadow:0 24px 60px rgba(0,0,0,0.6);
    background:var(--coffee-dark)
}

button:active{
    transform:translateY(-6px)
}

.result-card{
    background:var(--surface);
    border-radius:22px;
    padding:56px;
    margin:60px auto;
    max-width:1200px;
    box-shadow:var(--shadow);
    border:1px solid rgba(212,175,55,0.18);
    display:none;
    animation:fadeIn .9s ease-out
}

@keyframes fadeIn{
    from{opacity:0;transform:translateY(40px)}
    to{opacity:1;transform:none}
}

.title{
    font-family:'Playfair Display',serif;
    font-size:2.9em;
    text-align:center;
    color:var(--gold);
    margin-bottom:44px;
    letter-spacing:2px;
    position:relative
}

.title::after{
    content:'';
    position:absolute;
    left:50%;bottom:-22px;
    transform:translateX(-50%);
    width:140px;
    height:3px;
    background:linear-gradient(90deg,transparent,var(--gold),var(--gold-light),var(--gold),transparent);
    border-radius:2px;
    box-shadow:0 0 10px rgba(212,175,55,0.5)
}

pre{
    background:rgba(15,10,5,0.8);
    color:var(--cream);
    padding:36px;
    border-radius:16px;
    font-family:'Courier New',monospace;
    font-size:1.12em;
    line-height:1.9;
    border:1px solid rgba(212,175,55,0.22);
    overflow-x:auto;
    box-shadow:inset 0 8px 24px rgba(0,0,0,0.5)
}

img{
    max-width:100%;
    border-radius:16px;
    border:6px double var(--gold);
    box-shadow:0 20px 50px rgba(0,0,0,0.65);
    display:block;
    margin:36px auto;
    transition:transform .7s ease
}

img:hover{
    transform:scale(1.03)
}

@media (max-width:768px){
    .buttons{grid-template-columns:1fr;gap:32px}
    button{padding:32px 20px;font-size:1.45em}
    h1{margin:60px 0 80px}
    .result-card{padding:40px}
}

===================================================================================================================
  
templates / index.html:

<!DOCTYPE html>
<html lang="uk" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>HTTP запити</title>
    <link href="https://fonts.googleapis.com/css2?family=Cormorant+Garamond:wght@500;600;700&family=Playfair+Display:wght@700;900&display=swap" rel="stylesheet">
    <link rel="stylesheet" th:href="@{style.css}" href="style.css">
</head>
<body>

<div class="container">
    <div class="buttons">
        <button onclick="loadData('/api/text')">Завантажити текст</button>
        <button onclick="loadData('/api/image')">Показати котика</button>
        <button onclick="loadData('/api/json-object')">JSON-об’єкт</button>
        <button onclick="loadData('/api/json-array')">JSON-масив</button>
        <button onclick="loadData('/api/post')">POST-запит</button>
    </div>

    <div id="result" class="result-card">
        <div class="title" id="resultTitle">Натисни кнопку</div>
        <div id="resultContent"></div>
    </div>
</div>

<script>
// курсор на кнопці - центр градієнта
document.querySelectorAll('button').forEach(btn => {
    btn.addEventListener('mousemove', e => {
        const rect = btn.getBoundingClientRect();
        const x = ((e.clientX - rect.left) / rect.width) * 100 + '%';
        const y = ((e.clientY - rect.top) / rect.height) * 100 + '%';
        btn.style.setProperty('--x', x);
        btn.style.setProperty('--y', y);
    });
    btn.addEventListener('mouseleave', () => {
        btn.style.setProperty('--x', '50%');
        btn.style.setProperty('--y', '50%');
    });
});

async function loadData(url) {
    const titleEl = document.getElementById('resultTitle');
    const contentEl = document.getElementById('resultContent');
    const card = document.getElementById('result');

    titleEl.textContent = 'Зачекайте...';
    contentEl.innerHTML = '';
    card.style.display = 'block';

    try {
        const res = await fetch(url);
        const data = await res.json();
        titleEl.textContent = data.title || 'Результат';
        if (data.imageBase64) {
            contentEl.innerHTML = `<img src="${data.imageBase64}" alt="Кіт">`;
        } else if (data.content) {
            contentEl.innerHTML = `<pre>${data.content}</pre>`;
        }
    } catch (err) {
        titleEl.textContent = 'Помилка';
        contentEl.innerHTML = `<pre style="color:#A0522D;">${err.message}</pre>`;
    }
}
</script>
</body>
</html>

===================================================================================================================

build.gradle:

plugins {
	id 'java'
	id 'org.springframework.boot' version '4.0.0-SNAPSHOT'
	id 'io.spring.dependency-management' version '1.1.7'
}

group = 'site.sunmeat'
version = '0.0.1-SNAPSHOT'
description = 'Demo project for Spring Boot'

java {
	toolchain {
		languageVersion = JavaLanguageVersion.of(25)
	}
}

repositories {
	mavenCentral()
	maven { url = 'https://repo.spring.io/snapshot' }
}

dependencies {
	implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
    implementation 'org.springframework.boot:spring-boot-starter-webflux' // !!!
}

tasks.named('test') {
	useJUnitPlatform()
}