HTTPDNS:Praktik terbaik penggunaan HTTPDNS dengan Apache HttpClient di Java

1. Latar Belakang

Apache HttpClient adalah pustaka jaringan HTTP yang banyak digunakan dalam ekosistem Java dan tersedia dalam dua versi utama: 4.x dan 5.x. Anda dapat mengintegrasikan HTTPDNS ke dalam HttpClient dengan mengimplementasikan antarmuka DnsResolver.

2. Implementasikan DnsResolver kustom

import org.apache.hc.client5.http.DnsResolver;
import com.alibaba.sdk.java.httpdns.HttpDnsClient;
import com.alibaba.sdk.java.httpdns.HTTPDNSResult;
import com.alibaba.sdk.java.httpdns.RequestIpType;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;

public class HttpDnsResolver implements DnsResolver {
    
    private final HttpDnsClient httpDnsClient;
    
    public HttpDnsResolver(HttpDnsClient httpDnsClient) {
        this.httpDnsClient = httpDnsClient;
    }

    @Override
    public String resolveCanonicalHostname(String host) {
        return host;
    }

    @Override
    public InetAddress[] resolve(String host) throws UnknownHostException {
        HTTPDNSResult result = httpDnsClient.getHttpDnsResultForHostSyncNonBlocking(host, RequestIpType.both);

        List<InetAddress> addresses = new ArrayList<>();
        try {
            if (result != null && result.getIps() != null) {
                for (String ip : result.getIps()) {
                    addresses.add(InetAddress.getByName(ip));
                }
            }
            if (result != null && result.getIpv6s() != null) {
                for (String ip : result.getIpv6s()) {
                    addresses.add(InetAddress.getByName(ip));
                }
            }
        } catch (UnknownHostException e) {
            // Abaikan kegagalan mengurai satu alamat IP.
        }
        
        if (!addresses.isEmpty()) {
            return addresses.toArray(new InetAddress[0]);
        }
        
        // Turun ke DNS sistem.
        return InetAddress.getAllByName(host);
    }
}

import org.apache.http.conn.DnsResolver;
import com.alibaba.sdk.java.httpdns.HttpDnsClient;
import com.alibaba.sdk.java.httpdns.HTTPDNSResult;
import com.alibaba.sdk.java.httpdns.RequestIpType;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;

public class HttpDnsResolver4 implements DnsResolver {
    
    private final HttpDnsClient httpDnsClient;
    
    public HttpDnsResolver4(HttpDnsClient httpDnsClient) {
        this.httpDnsClient = httpDnsClient;
    }

    @Override
    public InetAddress[] resolve(String host) throws UnknownHostException {
        HTTPDNSResult result = httpDnsClient.getHttpDnsResultForHostSyncNonBlocking(host, RequestIpType.both);

        List<InetAddress> addresses = new ArrayList<>();
        try {
            if (result != null && result.getIps() != null) {
                for (String ip : result.getIps()) {
                    addresses.add(InetAddress.getByName(ip));
                }
            }
            if (result != null && result.getIpv6s() != null) {
                for (String ip : result.getIpv6s()) {
                    addresses.add(InetAddress.getByName(ip));
                }
            }
        } catch (UnknownHostException e) {
            // Abaikan kegagalan mengurai satu alamat IP.
        }
        
        if (!addresses.isEmpty()) {
            return addresses.toArray(new InetAddress[0]);
        }
        
        // Turun ke DNS sistem.
        return InetAddress.getAllByName(host);
    }
}

3. Konfigurasikan HttpClient

import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
import org.apache.hc.client5.http.io.HttpClientConnectionManager;

HttpDnsClient httpDnsClient = HttpDnsClient.getClient(accountId);

HttpClientConnectionManager connectionManager = PoolingHttpClientConnectionManagerBuilder.create()
    .setDnsResolver(new HttpDnsResolver(httpDnsClient))
    .build();

CloseableHttpClient httpClient = HttpClients.custom()
    .setConnectionManager(connectionManager)
    .build();

import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

HttpDnsClient httpDnsClient = HttpDnsClient.getClient(accountId);

CloseableHttpClient httpClient = HttpClients.custom()
    .setDnsResolver(new HttpDnsResolver4(httpDnsClient))
    .build();

4. Ringkasan

Keunggulan utama menggunakan Apache HttpClient dengan HTTPDNS adalah:

• Implementasi sederhana: Cukup implementasikan antarmuka DnsResolver untuk mengintegrasikan HTTPDNS.

• Fleksibilitas tinggi: Berfungsi dalam berbagai skenario seperti HTTPS, Server Name Indication (SNI), dan pengaturan cookie tanpa perlu menangani langkah tambahan seperti validasi Sertifikat atau verifikasi Nama domain.

• Kompatibilitas versi: Mendukung HttpClient 4.x dan 5.x.