Java中获取网络数据的多种最佳实践方法

HttpClient client = HttpClient.newBuilder().build();

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://horstmann.com/index.html"))
    .GET()
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

String result = response.body();
System.out.println(result);

try (InputStream in = new URI("https://horstmann.com/index.html").toURL().openStream()) {
    byte[] bytes = in.readAllBytes();
    String result = new String(bytes);
    System.out.println(result);
}

try (InputStream in = new URI("https://horstmann.com/index.html").toURL().openStream();
     OutputStream out = Files.newOutputStream(Path.of("index.html"))) {
    in.transferTo(out);
}

URL url = new URI("https://dog.ceo/api/breeds/image/random").toURL();
Map<String, Object> result = com.fasterxml.jackson.jr.ob.JSON.std.mapFrom(url);

System.out.println(result);
// {message=https://images.dog.ceo/breeds/...jpg, status=success}

URL imgUrl = new URI(result.get("message").toString()).toURL();
BufferedImage img = javax.imageio.ImageIO.read(imgUrl);

// 输出图片宽高
System.out.println("Width: " + img.getWidth());
System.out.println("Height: " + img.getHeight());