首先看一下目錄結構：

module-info.java 裡面寫要匯入的模組：

module http2{
    requires jdk.incubator.httpclient; #需要的模組
    exports com.zm.test;               #匯入到某個包下
}

接下來寫post請求：

package com.zm.test;

import jdk.incubator.http.HttpClient;
import jdk.incubator.http.HttpRequest;
import jdk.incubator.http.HttpResponse;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.zip.GZIPInputStream;


public class Http2Example02 {
    public static void main(String[] args) throws URISyntaxException, IOException, InterruptedException {
        URI uri = new URI("https://www.baidu.com/");
        HttpRequest.Builder post = HttpRequest.newBuilder(uri).POST(HttpRequest.BodyProcessor.fromString("###要請求的引數"));
        //post.setHeader可以設定UA、Cookie等引數
        post.setHeader("User-Agent", "Mozilla/5.0 (iPhone; CPU iPhone OS 10_3 like Mac OS X) AppleWebKit/602.1.50 (KHTML, like Gecko) CriOS/56.0.2924.75 Mobile/14E5239e Safari/602.1");

        HttpClient httpClient = HttpClient.newHttpClient();
        HttpResponse httpResponse = httpClient.send(post.build(), HttpResponse.BodyHandler.asString());
        int code = httpResponse.statusCode();
        System.out.println(code);
        System.out.println(uncompress(httpResponse.body().toString().getBytes()));
    }
    public static String uncompress(byte[] bytes) {
        if (bytes == null || bytes.length == 0) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        try {
            GZIPInputStream ungzip = new GZIPInputStream(in);
            byte[] buffer = new byte[256];
            int n;
            while ((n = ungzip.read(buffer)) >= 0) {
                out.write(buffer, 0, n);
            }
        } catch (IOException e) {
            System.out.println(e);
        }

        return out.toString();
    }

}