HTTP-Client und Webtest

package at.aydin.lab.http.legacy;

// Design Pattern: Adapter – kapselt HttpURLConnection hinter einer kleinen Client-API.
import java.io.*;
import java.net.*;
import java.nio.charset.StandardCharsets;

public final class LegacyHttpClient {
    public String get(String url) throws IOException {
        HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
        connection.setRequestMethod("GET");
        try (InputStream in = connection.getInputStream()) {
            return new String(in.readAllBytes(), StandardCharsets.UTF_8);
        } finally {
            connection.disconnect();
        }
    }
}

package at.aydin.lab.http.modern;

import java.net.*;
import java.net.http.*;
import java.nio.charset.StandardCharsets;
import java.time.Duration;

// Design Pattern: Adapter
// Zweck: Adaptiert java.net.http.HttpClient an den fachlichen TextTransport-Port.
public final class JavaHttpTransport implements TextTransport {
    private final HttpClient client = HttpClient.newBuilder().connectTimeout(Duration.ofSeconds(5)).build();
    public String get(URI uri) throws Exception {
        HttpRequest request = HttpRequest.newBuilder(uri).timeout(Duration.ofSeconds(10)).GET().build();
        return client.send(request, HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8)).body();
    }
}

package at.aydin.lab.http.legacy;

// Design Pattern: Adapter – kapselt HttpURLConnection hinter einer kleinen Client-API.
import java.io.*;
import java.net.*;
import java.nio.charset.StandardCharsets;

public final class LegacyHttpClient {
    public String get(String url) throws IOException {
        HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
        connection.setRequestMethod("GET");
        try (InputStream in = connection.getInputStream()) {
            return new String(in.readAllBytes(), StandardCharsets.UTF_8);
        } finally {
            connection.disconnect();
        }
    }
}

package at.aydin.lab.http.modern;

import java.net.URI;

// Design Pattern: Port
// Zweck: HTTP-Transport wird für Tests und alternative Implementierungen austauschbar.
@FunctionalInterface
public interface TextTransport {
    String get(URI uri) throws Exception;
}

package at.aydin.lab.http.modern;

import java.net.URI;
import java.util.regex.*;

public final class PageTitleService {
    private static final Pattern TITLE = Pattern.compile("<title>(.*?)</title>", Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
    private final TextTransport transport;
    public PageTitleService(TextTransport transport) {
        this.transport = transport;
    }

    public String title(URI uri) throws Exception {
        Matcher m = TITLE.matcher(transport.get(uri));
        return m.find() ? m.group(1).trim() : "";
    }
}