httpClient通过digest调用海康威视/ISAPI/Streaming/channels/1/picture接口的代码

以下是使用httpClient通过digest调用海康威视/ISAPI/Streaming/channels/1/picture接口的示例代码：

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.auth.DigestScheme;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class HttpDigestAuthentication {

    private static final String USERNAME = "admin";
    private static final String PASSWORD = "12345";
    private static final String URI = "http://192.168.1.100/ISAPI/Streaming/channels/1/picture";

    public static void main(String[] args) throws NoSuchAlgorithmException, IOException {

        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        HttpGet httpGet = new HttpGet(URI);

        // Calculate digest
        DigestScheme digestScheme = new DigestScheme();
        digestScheme.overrideParamter("realm", "Digest Authentication");
        digestScheme.overrideParamter("nonce", "1234567890abcdef");
        digestScheme.overrideParamter("qop", "auth");
        digestScheme.overrideParamter("algorithm", "MD5");
        digestScheme.overrideParamter("nc", "00000001");
        digestScheme.overrideParamter("cnonce", "abcdef");
        String digest = digestScheme.authenticate(new org.apache.http.auth.UsernamePasswordCredentials(USERNAME, PASSWORD), httpGet, null);

        // Set authorization header
        httpGet.setHeader("Authorization", digest);

        // Execute request and read response
        CloseableHttpResponse response = httpClient.execute(httpGet);
        String responseBody = EntityUtils.toString(response.getEntity());
        System.out.println(responseBody);

        // Close resources
        response.close();
        httpClient.close();

    }

}

请注意，这只是一个示例代码，实际应用中，需要根据海康威视设备的实际情况调整参数。