ApsaraVideo VOD:Configure the preview feature

import com.alibaba.fastjson.JSONObject;
import com.aliyuncs.DefaultAcsClient;
import com.aliyuncs.profile.DefaultProfile;
import com.aliyuncs.exceptions.ClientException;
import com.aliyuncs.vod.model.v20170321.GetPlayInfoRequest;
import com.aliyuncs.vod.model.v20170321.GetPlayInfoResponse;

/**
 * @date 2021/12/30
 */
public class VodPreviewTest {
    public static void main(String[] args) throws ClientException {
        // Specify the region in which ApsaraVideo VOD is activated. For more information, see Region IDs of ApsaraVideo VOD. 
        String regionId = "cn-shanghai";
        // The AccessKey pair of an Alibaba Cloud account has permissions on all API operations. We recommend that you use a RAM user to call API operations or perform routine O&M. 
        // We recommend that you not include your AccessKey pair (AccessKey ID and AccessKey secret) in your project code. Otherwise, the AccessKey pair may be leaked and the security of all resources within your account may be compromised. 
        // In this example, ApsaraVideo VOD reads the AccessKey pair from the environment variables to implement identity verification for API access. Before you run the sample code, configure the environment variables ALIBABA_CLOUD_ACCESS_KEY_ID and ALIBABA_CLOUD_ACCESS_KEY_SECRET. 
        // Specify your AccessKey ID.
        String accessKeyId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
        // Specify your AccessKey secret.
        String accessKeySecret = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
        // Specify the ID of the video. Example: 533606af570e4db4961248d0978b****. If you upload a video by using the ApsaraVideo VOD console, you can choose Media Files > Audio/Video in the left-side navigation pane of the ApsaraVideo VOD console to view the ID of the video. If you upload a video by calling the CreateUploadVideo operation, the ID of the video is the value of VideoId in the response. 
        String videoId = "<your videoId>";
        DefaultAcsClient client = InitVodClient(regionId, accessKeyId, accessKeySecret);
        GetPlayInfoResponse response = null;
        try {
            response = getPlayInfo(client, videoId);
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("response = " + JSONObject.toJSONString(response));

    }

    /**
     * Initialize the client.
     *
     * @param regionId
     * @param accessKeyId
     * @param accessKeySecret
     * @return
     * @throws ClientException
     */
    public static DefaultAcsClient InitVodClient(String regionId, String accessKeyId, String accessKeySecret) throws ClientException {
        DefaultProfile profile = DefaultProfile.getProfile(regionId, accessKeyId, accessKeySecret);
        DefaultAcsClient client = new DefaultAcsClient(profile);
        return client;
    }

    /**
     * Obtain the preview URL.
     *
     * @param client
     * @param videoId
     * @return
     * @throws Exception
     */
    public static GetPlayInfoResponse getPlayInfo(DefaultAcsClient client, String videoId) throws Exception {
        GetPlayInfoRequest request = new GetPlayInfoRequest();
        request.setVideoId(videoId);
        // Specify the validity period in seconds. Default value: 3600.
        request.setAuthTimeout(3600L);
        request.setFormats("mp4");
        JSONObject playConfig = new JSONObject();
        // Specify the preview duration in seconds. Minimum value: 1.
        playConfig.put("PreviewTime", "30");
        request.setPlayConfig(playConfig.toJSONString());
        return client.getAcsResponse(request);
    }
}
                

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.4</version>
</dependency>

    import java.util.UUID;
    import java.net.URL;
    import org.apache.commons.lang3.StringUtils;
    private String generateRand() {
        return UUID.randomUUID().toString().replaceAll("-", "");
    }
    private String md5(String str) {
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update(str.getBytes("UTF-8"));
            return bytesToHex(md5.digest());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public String genAuthKey(String object, String privateKey, Long expireTime, Long previewTime) {
        String rand = "0";
        String uid = "0";
        if (StringUtils.isBlank(privateKey)) {
            return "";
        }
        rand = generateRand();
        long timestamp = System.currentTimeMillis() / 1000 + (expireTime == null ? 0 : expireTime);
        String authStr = timestamp + "-" + rand + "-" + uid;
        String md5Str = object + "-" + authStr + "-" + privateKey;
        if(previewTime!=0)
            md5Str = md5Str + "-" + previewTime;
        String auth_key = authStr + "-" + this.md5(md5Str);
        return auth_key;
    }

    public void previewTest() throws Exception {
        try {
            String key = "<Your PrivateKey>";// The primary key or secondary key that you configured in the VOD console. For more information, see Enable the preview feature. 
            String fileUrl = "<Your File URL>";// The URL of the file. Example: http://example.aliyundoc.com/test/bee21427ca3346848835c1bd786054c5-19bd8528c1d51576cd726cf86471ca0****.mp4.
            URL url = new URL(fileUrl);
            String file = url.getFile();
            Long previewTime = 120L;// The preview duration. 
            Long expireTime = 1800L;
            String auth_key =genAuthKey(file, key, expireTime, previewTime);
            fileUrl = fileUrl + "?auth_key=" + auth_key;
            if(previewTime != 0)
                fileUrl = fileUrl + "&end=" + previewTime;
            System.out.println(fileUrl);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }