How to fetch certificates from a TLS connection

CertFetcher.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.UnknownHostException;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

public class CertFetcher {
    private String hostname;
    private int port;

    public CertFetcher(String hostname, int port) {
        this.hostname = hostname;
        this.port = port;
    }

    public X509Certificate[] getCerts() throws UnknownHostException,
            IOException,
            NoSuchAlgorithmException,
            KeyManagementException {

        SSLContext sslCtx = SSLContext.getInstance("TLS");
        sslCtx.init(null, new TrustManager[] { new X509TrustManager() {

            private X509Certificate[] accepted;

            @Override
            public void checkClientTrusted(X509Certificate[] xcs, String string)
                    throws CertificateException {
            }

            @Override
            public void checkServerTrusted(X509Certificate[] xcs, String string)
                    throws CertificateException {
                accepted = xcs;
            }

            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return accepted;
            }
        } }, null);

        try (SSLSocket s = (SSLSocket) sslCtx.getSocketFactory()
                .createSocket(hostname, port)) {
            s.startHandshake();
            Certificate[] certs = s.getSession().getPeerCertificates();
            X509Certificate[] x509Certs = new X509Certificate[certs.length];
            for (int i = 0; i < certs.length; i++) {
                x509Certs[i] = (X509Certificate) certs[i];
            }
            return x509Certs;
        }
    }
}