使用Java从https获取图像 [英] Getting images from https with Java

问题描述

有没有办法从带有Java的https网址获取图片？

Is there a way to get images from a https url with Java?

到目前为止我正在尝试：

What I am trying so far:

URL url = new URL("https://ns6.host.md:8443/sitepreview/http/zugo.md/media/images/thumb/23812__yu400x250.jpg");

System.out.println("Image: " + ImageIO.read(url));

但是，我得到：

Exception in thread "main" javax.imageio.IIOException: Can't get input stream from URL!
Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No 
Caused by: java.security.cert.CertificateException: No name matching ns6.host.md found

我该怎么办呢？我在那个网址上有超过6k的图像，我必须提取。

How can I go through that? I have more than 6k images on that url that I have to fetch.

推荐答案

有两个问题。您可以使用浏览器访问该网站，并查看错误。

There are two problems. You can use your browser to access the site, and see the errors.

1. 服务器证书是自签名的，不受信任的通过Java。您可以将其添加到信任存储区。

1. The server certificate is self-signed, not trusted by Java. you can add it to the trust store.

服务器证书与主机名ns6.host.md不匹配，您需要 HostnameVerifier 忽略它。

The server certificate does not match the host name "ns6.host.md", and you need a HostnameVerifier that ignores it.

另一个答案说同样的事情，它提供了代码，不幸的是使用了一些私有API。

The other answer says the same thing, and it provides code, which unfortunately uses some private APIs.

如果有人感兴趣的话，如何解决它在bayou HttpClient中的示例：
https://gist.github.com/zhong-j-yu/22af353e2c5a5aed5857

Example how to solve it in bayou HttpClient, if anyone is interested: https://gist.github.com/zhong-j-yu/22af353e2c5a5aed5857

public static void main(String[] args) throws Exception
{
    HttpClient client = new HttpClientConf()
        .sslContext(new SslConf().trustAll().createContext()) // trust self-signed certs
        .sslEngineConf(engine -> disableHostNameVerification(engine))
        .trafficDump(System.out::print)
        .newClient();
    // typically, app creates one client and use it for all requests

    String url = "https://ns6.host.md:8443/sitepreview/http/zugo.md/media/images/thumb/23812__yu400x250.jpg";
    HttpResponse response = client.doGet(url).sync();
    ByteBuffer bb = response.bodyBytes(Integer.MAX_VALUE).sync();

    InputStream is = new ByteArrayInputStream(bb.array(), bb.arrayOffset()+bb.position(), bb.remaining());
    BufferedImage image = ImageIO.read(is);

}

static void disableHostNameVerification(SSLEngine engine)
{
    SSLParameters sslParameters = engine.getSSLParameters();
    {
        // by default, it's set to "HTTPS", and the server certificate must match the request host.
        // disable it for this example, since the server certificate is ill constructed.
        sslParameters.setEndpointIdentificationAlgorithm(null);
    }
    engine.setSSLParameters(sslParameters);
}

这篇关于使用Java从https获取图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！