cURLからJavaへの変換ガイド（Java 11+ HttpClient、OkHttp & Spring WebClient）

// Java 11+ Native java.net.http.HttpClient
// Built into JDK 11, 17, 21+ standard library — zero external dependencies required!

package com.example.client;

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;

public class HttpClientExample {

    public static void main(String[] args) {
    try {
        // 1. Configure and build HttpClient
        HttpClient client = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_2)
            .connectTimeout(Duration.ofSeconds(30))
            .build();

        // 2. Prepare request payload
        String requestBody = "{\"title\": \"Bug in auth session\", \"body\": \"Need to verify token expiration handling\", \"labels\": [\"bug\", \"priority\"]}";

        // 3. Build HttpRequest
        HttpRequest.Builder requestBuilder = HttpRequest.newBuilder()
            .uri(URI.create("https://api.github.com/repos/octocat/Hello-World/issues"))
            .timeout(Duration.ofSeconds(30))
            .header("Accept", "application/vnd.github+json")
            .header("Authorization", "Bearer gho_16C7e42F292c6912E7710c838347Ae178B4a")
            .header("X-GitHub-Api-Version", "2022-11-28")
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(requestBody));
        HttpRequest request = requestBuilder.build();

        // Synchronous execution
        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

        System.out.println("Status Code: " + response.statusCode());
        System.out.println("Response Body:\n" + response.body());
    } catch (Exception e) {
        System.err.println("HTTP Client Error: " + e.getMessage());
        e.printStackTrace();
    }
    }
}