MyRequest.java

package http;

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest;
import java.time.Duration;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;

public class MyRequest extends HttpRequest {
    private final String rawHttpRequest;
    private final String method;
    private final String path;
    private final String httpVersionText;
    private final URI uri;
    private final HttpHeaders headers;
    private final String body;
    private final Optional<BodyPublisher> bodyPublisher;

    private MyRequest(
            String rawHttpRequest,
            String method,
            String path,
            String httpVersionText,
            URI uri,
            HttpHeaders headers,
            String body
    ) {
        this.rawHttpRequest = rawHttpRequest;
        this.method = method;
        this.path = path;
        this.httpVersionText = httpVersionText;
        this.uri = uri;
        this.headers = headers;
        this.body = body;

        this.bodyPublisher = body == null || body.isEmpty()
                ? Optional.empty()
                : Optional.of(BodyPublishers.ofString(body));
    }

    public static MyRequest fromRaw(String rawHttpRequest) {
        String[] parts = rawHttpRequest.split("\\r\\n\\r\\n", 2);

        String headerPart = parts[0];
        String body = parts.length > 1 ? parts[1] : "";

        String[] lines = headerPart.split("\\r\\n");

        String[] startLine = lines[0].split(" ", 3);

        String method = startLine[0];
        String path = startLine[1];
        String httpVersionText = startLine[2];

        Map<String, List<String>> headerMap = new LinkedHashMap<>();

        for (int i = 1; i < lines.length; i++) {
            String line = lines[i];

            int colonIndex = line.indexOf(":");

            if (colonIndex == -1) {
                continue;
            }

            String name = line.substring(0, colonIndex).trim();
            String value = line.substring(colonIndex + 1).trim();

            headerMap.put(name, List.of(value));
        }

        HttpHeaders headers = HttpHeaders.of(headerMap, (name, value) -> true);
        URI uri = createUri(path, headers);

        return new MyRequest(
                rawHttpRequest,
                method,
                path,
                httpVersionText,
                uri,
                headers,
                body
        );
    }

    private static URI createUri(String path, HttpHeaders headers) {
        String host = headers.firstValue("Host").orElse("localhost");
        return URI.create("http://" + host + path);
    }

    public String rawHttpRequest() {
        return rawHttpRequest;
    }

    public String path() {
        return path;
    }

    public String httpVersionText() {
        return httpVersionText;
    }

    public Optional<String> header(String name) {
        return headers.firstValue(name);
    }

    public String body() {
        return body;
    }

    @Override
    public Optional<BodyPublisher> bodyPublisher() {
        return bodyPublisher;
    }

    @Override
    public String method() {
        return method;
    }

    @Override
    public Optional<Duration> timeout() {
        return Optional.empty();
    }

    @Override
    public boolean expectContinue() {
        return false;
    }

    @Override
    public URI uri() {
        return uri;
    }

    @Override
    public Optional<HttpClient.Version> version() {
        if ("HTTP/2".equals(httpVersionText) || "HTTP/2.0".equals(httpVersionText)) {
            return Optional.of(HttpClient.Version.HTTP_2);
        }

        if ("HTTP/1.1".equals(httpVersionText)) {
            return Optional.of(HttpClient.Version.HTTP_1_1);
        }

        return Optional.empty();
    }

    @Override
    public HttpHeaders headers() {
        return headers;
    }
}