java怎么调用海康威视/ISAPI/ContentMgmt/StreamingProxy/channels/101/picture的接口digest认证

调用海康威视/ISAPI/ContentMgmt/StreamingProxy/channels/101/picture的接口时，需要进行摘要认证(digest authentication)。以下是Java调用海康威视/ISAPI/ContentMgmt/StreamingProxy/channels/101/picture接口的示例代码：

import java.io.*;
import java.net.*;
import java.security.*;
import java.util.*;
import javax.xml.bind.DatatypeConverter;

public class HttpDigestAuth {

    public static void main(String[] args) throws Exception {

        String url = "http://192.168.1.64/ISAPI/ContentMgmt/StreamingProxy/channels/101/picture";
        String username = "admin";
        String password = "12345";

        // create a random client nonce
        SecureRandom random = new SecureRandom();
        byte[] clientNonce = new byte[16];
        random.nextBytes(clientNonce);

        // create the initial request
        HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
        conn.setRequestMethod("GET");
        conn.setRequestProperty("Authorization", "Digest username=\"" + username + "\", realm=\"IP Camera\", nonce=\"" + getNonce(conn) + "\", uri=\"" + conn.getURL().getPath() + "\", qop=auth, nc=00000001, cnonce=\"" + DatatypeConverter.printHexBinary(clientNonce) + "\", response=\"" + getResponse(conn, username, password, clientNonce) + "\"");
        conn.connect();

        // read the response
        BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        reader.close();
    }

    private static String getNonce(HttpURLConnection conn) {

        // get the server nonce from the WWW-Authenticate header
        String authenticateHeader = conn.getHeaderField("WWW-Authenticate");
        int start = authenticateHeader.indexOf("nonce=\"") + 7;
        int end = authenticateHeader.indexOf("\"", start);
        String serverNonce = authenticateHeader.substring(start, end);

        return serverNonce;
    }

    private static String getResponse(HttpURLConnection conn, String username, String password, byte[] clientNonce) throws NoSuchAlgorithmException {

        // build the HA1 hash (MD5(username:realm:password))
        String realm = "IP Camera";
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] ha1Input = (username + ":" + realm + ":" + password).getBytes();
        md.update(ha1Input);
        byte[] ha1 = md.digest();

        // build the HA2 hash (MD5(method:uri))
        String method = conn.getRequestMethod();
        String uri = conn.getURL().getPath();
        md.reset();
        byte[] ha2Input = (method + ":" + uri).getBytes();
        md.update(ha2Input);
        byte[] ha2 = md.digest();

        // build the response hash (MD5(HA1:nonce:nonceCount:cnonce:qop:HA2))
        String serverNonce = getNonce(conn);
        String nonceCount = "00000001";
        String qop = "auth";
        String responseInput = DatatypeConverter.printHexBinary(ha1) + ":" + serverNonce + ":" + nonceCount + ":" + DatatypeConverter.printHexBinary(clientNonce) + ":" + qop + ":" + DatatypeConverter.printHexBinary(ha2);
        md.reset();
        byte[] responseInputBytes = responseInput.getBytes();
        md.update(responseInputBytes);
        byte[] response = md.digest();

        return DatatypeConverter.printHexBinary(response);
    }
}

需要注意的是，调用该接口时需要替换url、username和password变量的值为相应的实际值。此外，该示例代码中使用的是MD5哈希算法，如果需要使用其他哈希算法，可以替换相应的代码。