Using HTTP/2 Client in Java 9

To use HTTP/2 in Java 9, it's required to declare the dependency of module jdk.incubator.httpclient. Here is the Java 9 module overview summary.

Assume the root package is com.jdk9.http.

To use module jdk.incubator.httpclient module, create module-info.java file with content:

Java

module com.jdk9.http {
    requires jdk.incubator.httpclient;
}

Create HTTPClientTest.java with following content to use HTTP Put method:

Java

package com.jdk9.http;

import jdk.incubator.http.HttpClient;
import jdk.incubator.http.HttpRequest;
import jdk.incubator.http.HttpResponse;
import java.io.IOException;
import java.net.URI;

public class HttpClientTest {
    public static void main(String args[]){

        HttpClient client = HttpClient.newHttpClient();

        HttpRequest req =
                HttpRequest.newBuilder(URI.create("<the url>"))
                        .headers("User-Agent","Java", "Content-Type", "application/json")
                        .PUT(HttpRequest.BodyProcessor.fromString("<body string>"))
                        .build();

        HttpResponse<String> resp = null;
        try {
            resp = client.send(req, HttpResponse.BodyHandler.asString());
            System.out.println(resp.body());
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}