a.java

SSLContext sslContext = SSLContexts.custom()
        .loadTrustMaterial((TrustStrategy) (chain, authType) -> true)
        .build();
try (CloseableHttpClient httpClient = HttpClients.custom()
        .setSSLContext(sslContext)
        .setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE)
        .build()) {

    String response = Executor.newInstance(httpClient)
            .execute(Request.Get("https://localhost:8443/"))
            .returnContent().asString();
    assertThat(response).isEqualTo("Hello on port 8443, secure: true");
}