cURLing/src/ovh/alexisdelhaie/curling/web/HttpClient.java

package ovh.alexisdelhaie.curling.web;

import java.io.*;
import java.net.*;
import java.util.Map;

public class HttpClient {

    public static String CRLF = "\r\n";
    public static int DEFAULT_PORT = 80;
    public static int DEFAULT_TIMEOUT = 10000;

    protected InetAddress addr;
    protected URL url;
    protected boolean valid;
    protected Method method;
    protected Map<String, String> headers;
    protected String body;

    public HttpClient(String u, Method method, String body, Map<String, String> headers) {
        try {
            URL url = new URL(u);
            addr = resolve(url.getHost());
            this.url = url;
            this.headers = headers;
            this.method = method;
            this.body = body;
            valid = true;
        } catch (UnknownHostException | MalformedURLException e) {
            valid = false;
        }
    }

    public InetAddress getAddr() {
        return addr;
    }

    public URL getUrl() {
        return url;
    }

    public Method getMethod() {
        return method;
    }

    public Map<String, String> getHeaders() {
        return headers;
    }

    public String getBody() {
        return body;
    }

    public boolean isDomain() {
        if(valid) {
            String comparable = url.getHost();
            if(comparable.contains(":")) {
                comparable = comparable.split(":")[0];
            }
            return !(comparable.equals(addr.getHostAddress()));
        }
        return false;
    }

    public String run() {
        String result = "";
        Socket s =  null;
        if (valid) {
            String request = String.format("%s%s%s", buildHeader(), CRLF, body);
            result += String.format("--- Request ---\n%s", request);
            BufferedOutputStream bos = null;
            BufferedInputStream bis = null;
            try {
                s = new Socket(addr, getPort());
                s.setKeepAlive(false);
                s.setSoTimeout(DEFAULT_TIMEOUT);
                if (s.isConnected()) {
                    bos = new BufferedOutputStream(s.getOutputStream());
                    bos.write(request.getBytes());
                    bos.flush();
                    bis = new BufferedInputStream(s.getInputStream());
                    byte[] b = bis.readAllBytes();
                    result += String.format("\n\n--- Response ---\n%s", new String(b, "UTF-8"));
                } else {
                    result += "/!\\ Not connected";
                }
            } catch (IOException io) {
                result += String.format("\n\n /!\\ %s", io.getMessage());
            } finally {
                try {
                    if(bos != null) {
                        bos.close();
                    }
                    if(bis != null) {
                        bis.close();
                    }
                    if(s != null && s.isConnected()) {
                        s.close();
                    }
                } catch (IOException e) {
                    result += String.format("\n\n /!\\ %s", e.getMessage());
                }
            }
        }
        return result;
    }

    private InetAddress resolve(String host) throws UnknownHostException {
        InetAddress[] addrs = InetAddress.getAllByName(host);
        return addrs[0];
    }

    protected String buildHeader() {
        String result = String.format("%s %s HTTP/1.1%s", method.toString(), getPath(), CRLF);
        result += getHostHeader();
        result += String.format("Accept: */*%s", CRLF);
        result += String.format("Connection: close%s", CRLF);
        if(method == Method.POST || method == Method.PUT) {
            result += String.format("Content-Length: %d%s", body.length(), CRLF);
        }
        if(!headers.containsKey("User-Agent")) {
            result += String.format("User-Agent: cURLing/2.0 %s%s", System.getProperty("os.name"), CRLF);
        }
        if(headers != null) {
            for (Map.Entry<String, String> entry : headers.entrySet()) {
                if (isAuthorizedHeader(entry.getKey())) {
                    result += String.format("%s: %s%s", entry.getKey(), entry.getValue(), CRLF);
                }
            }
        }
        return result;
    }

    private boolean isAuthorizedHeader(String key) {
        boolean result = true;
        if (key.toUpperCase().equals("ACCEPT") || key.toUpperCase().equals("HOST") || key.toUpperCase().equals("CONNECTION")) {
            result = false;
        }
        return result;
    }

    public boolean isValid() {
        return valid;
    }

    private String getPath() {
        if(url.getPath().isBlank()) {
            return "/";
        }
        return url.getPath();
    }

    private String getHostHeader() {
        String result;
        if (url.getPort() != -1) {
            result = String.format("Host: %s:%d%s", url.getHost(), url.getPort(), CRLF);
        } else {
            result = String.format("Host: %s%s", url.getHost(), CRLF);
        }
        return result;
    }

    protected int getPort() {
        if(url.getPort() != -1) {
            return url.getPort();
        }
        return DEFAULT_PORT;
    }
}