调用视频点播服务接口,是向视频点播服务端发送HTTP请求(可通过HTTP或HTTPS通道发送),并获取响应结果的过程。视频点播服务端接收到用户请求后,对请求进行身份验证和参数验证,验证成功后,根据请求的指定参数提交或完成相应操作,并把处理结果以HTTP响应的形式返回给调用者。

以下Java示例代码演示了如何添加公共参数和私有参数、如何用请求参数构造规范化请求字符串、如何构造StringToSign字符串,以及如何获得OpenAPI地址,最终以Get方式发送Http请求,获取相应的响应结果。如果您需要使用以下示例,请替换示例中的必选参数及私有参数。

  • 添加jar包依赖
    注意 使用httpclient get请求。
      <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.1</version>
      </dependency>
    				
  • JAVA代码
    import org.apache.http.HttpResponse;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.config.RequestConfig;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    import sun.misc.BASE64Encoder;
    import javax.crypto.Mac;
    import javax.crypto.spec.SecretKeySpec;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.net.URI;
    import java.net.URISyntaxException;
    import java.net.URLEncoder;
    import java.security.SignatureException;
    import java.text.SimpleDateFormat;
    import java.util.*;
    import java.util.logging.Logger;
    
    /**
     * 视频点播OpenAPI调用示例
     * 以GetVideoPlayAuth接口为例,其他接口请替换相应接口名称及私有参数
     */
    public class Main {
    	//账号AccessKey信息请填写(必选)
    	private static String access_key_id = "";
    	//账号AccessKey信息请填写(必选)
    	private static String access_key_secret = "";
    	//STS临时授权方式访问时该参数为必选,使用主账号AccessKey和RAM子账号AccessKey不需要填写
    	private static String security_token = "";
    	//VOD API 的服务接入地址为:vod.{ApiRegion}.aliyuncs.com,{ApiRegion}请替换成对应API接入区域的标识
    	private final static String VOD_DOMAIN = "http://vod.cn-shanghai.aliyuncs.com";
    						
    	//以下参数不需要修改
    	private final static String ISO8601_DATE_FORMAT = "yyyy-MM-dd'T'HH:mm:ss'Z'";
    	private final static String HTTP_METHOD = "GET";
    	private final static String HMAC_SHA1_ALGORITHM = "HmacSHA1";
    	private final static String UTF_8 = "utf-8";
    	private final static Logger LOG = Logger.getLogger(Main.class.getName());
    
    public static void main(String[] args) throws Exception {
        //生成私有参数,不同API需要修改
        Map<String, String> privateParams = generatePrivateParamters();
        //生成公共参数,不需要修改
        Map<String, String> publicParams = generatePublicParamters();
        //生成OpenAPI地址,不需要修改
        String URL = generateOpenAPIURL(publicParams, privateParams);
        //发送HTTP GET 请求
        httpGet(URL);
    }
      /**
        * 生成视频点播OpenAPI私有参数
        * 不同API需要修改此方法中的参数
        * @return
       */
    private static Map<String, String> generatePrivateParamters() {
        // 接口私有参数列表, 不同API请替换相应参数
        Map<String, String> privateParams = new HashMap<>();
        // 视频ID
        privateParams.put("VideoId","5aed81b74ba84920be578cdfe004af4b");
        // API名称
        privateParams.put("Action", "GetVideoPlayAuth");
        return privateParams;
    }
      /**
       * 生成视频点播OpenAPI公共参数
       * 不需要修改
       * @return
       */
    private static Map<String, String> generatePublicParamters() {
        Map<String, String> publicParams = new HashMap<>();
        publicParams.put("Format", "JSON");
        publicParams.put("Version", "2017-03-21");
        publicParams.put("AccessKeyId", access_key_id);
        publicParams.put("SignatureMethod", "HMAC-SHA1");
        publicParams.put("Timestamp", generateTimestamp());
        publicParams.put("SignatureVersion", "1.0");
        publicParams.put("SignatureNonce", generateRandom());
        if (security_token != null && security_token.length() > 0) {
        	publicParams.put("SecurityToken", security_token);
        }
    	return publicParams;
    }
    
     /**
       * 生成OpenAPI地址
       * @param privateParams
       * @return
       * @throws Exception
       */
    private static String generateOpenAPIURL(Map<String, String> publicParams, Map<String, String> privateParams) {
    	return generateURL(VOD_DOMAIN, HTTP_METHOD, publicParams, privateParams);
    }
    /**
      * @param domain        请求地址
      * @param httpMethod    HTTP请求方式GET,POST等
      * @param publicParams  公共参数
      * @param privateParams 接口的私有参数
      * @return 最后的url
     */
    private static String generateURL(String domain, String httpMethod, Map<String, String> publicParams, Map<String, String> privateParams) {
    	List<String> allEncodeParams = getAllParams(publicParams, privateParams);
    	String cqsString = getCQS(allEncodeParams);
    	out("CanonicalizedQueryString = " + cqsString);
    	String stringToSign = httpMethod + "&" + percentEncode("/") + "&" + percentEncode(cqsString);
    	out("StringtoSign = " + stringToSign);
    	String signature = hmacSHA1Signature(access_key_secret, stringToSign);
    	out("Signature = " + signature);
    	return domain + "?" + cqsString + "&" + percentEncode("Signature") + "=" + percentEncode(signature);
    }
    
    private static List<String> getAllParams(Map<String, String> publicParams, Map<String, String> privateParams) {
      List<String> encodeParams = new ArrayList<String>();
    	if (publicParams != null) {
        	for (String key : publicParams.keySet()) {
          		String value = publicParams.get(key);
                //将参数和值都urlEncode一下。
                String encodeKey = percentEncode(key);
                String encodeVal = percentEncode(value);
                encodeParams.add(encodeKey + "=" + encodeVal);
            }
        }
        if (privateParams != null) {
            for (String key : privateParams.keySet()) {
                String value = privateParams.get(key);
                //将参数和值都urlEncode一下。
                String encodeKey = percentEncode(key);
                String encodeVal = percentEncode(value);
                encodeParams.add(encodeKey + "=" + encodeVal);
            }
        }
        return encodeParams;
    }
    /**
    * 参数urlEncode
    *
    * @param value
    * @return
    */
    private static String percentEncode(String value) {
    	try {
    		String urlEncodeOrignStr = URLEncoder.encode(value, "UTF-8");
    		String plusReplaced = urlEncodeOrignStr.replace("+", "%20");
    		String starReplaced = plusReplaced.replace("*", "%2A");
    		String waveReplaced = starReplaced.replace("%7E", "~");
    		return waveReplaced;
    	} catch (UnsupportedEncodingException e) {
    		e.printStackTrace();
    	}
    	return value;
    }
    
    /**
    * 获取CQS 的字符串
    *
    * @param allParams
    * @return
    */
    private static String getCQS(List<String> allParams) {
    	ParamsComparator paramsComparator = new ParamsComparator();
    	Collections.sort(allParams, paramsComparator);
    	String cqString = "";
    	for (int i = 0; i < allParams.size(); i++) {
    		cqString += allParams.get(i);
    		if (i != allParams.size() - 1) {
    			cqString += "&";
            }
    	}
    	return cqString;
    }
    
    private static class ParamsComparator implements Comparator<String> {
    	@Override
    	public int compare(String lhs, String rhs) {
    		return lhs.compareTo(rhs);
    	}
    }
    
    private static String hmacSHA1Signature(String accessKeySecret, String stringtoSign) {
    	try {
    		String key = accessKeySecret + "&";
    		try {
    			SecretKeySpec signKey = new SecretKeySpec(key.getBytes(), HMAC_SHA1_ALGORITHM);
    			Mac mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
    			mac.init(signKey);
    			byte[] rawHmac = mac.doFinal(stringtoSign.getBytes());
    			//按照Base64 编码规则把上面的 HMAC 值编码成字符串,即得到签名值(Signature)
    			return new String(new BASE64Encoder().encode(rawHmac));
                } catch (Exception e) {
    			throw new SignatureException("Failed to generate HMAC : " + e.getMessage());
            }
        } catch (SignatureException e) {
    		e.printStackTrace();
        }
    	return "";
    }
    
    /**
    * 生成随机数
    *
    * @return
    */
    private static String generateRandom() {
    	String signatureNonce = UUID.randomUUID().toString();
    	return signatureNonce;
    }
    
    /**
    * 生成当前UTC时间戳
    *
    * @return
    */
    public static String generateTimestamp() {
    	Date date = new Date(System.currentTimeMillis());
    	SimpleDateFormat df = new SimpleDateFormat(ISO8601_DATE_FORMAT);
    	df.setTimeZone(new SimpleTimeZone(0, "GMT"));
    	return df.format(date);
    }
    
    private static String httpGet(String url) throws Exception {
        CloseableHttpClient httpClient = null;
        try {
            httpClient = HttpClients.createDefault();
            HttpGet httpGet = new HttpGet();
            httpGet.setURI(new URI(url));
            RequestConfig requestConfig = RequestConfig.custom()
                    .setConnectTimeout(3000)
                    .setSocketTimeout(3000)
                    .build();
            httpGet.setConfig(requestConfig);
            HttpResponse result = httpClient.execute(httpGet);
    
            String str;
            try {
                /**读取服务器返回过来的json字符串数据**/
                str = EntityUtils.toString(result.getEntity());
                EntityUtils.consume(result.getEntity());
            } catch (Exception e) {
                e.printStackTrace();
                throw e;
            }
            out(str);
            // 这里可以解析视频云点播服务端的响应结果
            return str;
        } catch (URISyntaxException e) {
            e.printStackTrace();
            throw e;
        } catch (ClientProtocolException e) {
            e.printStackTrace();
            throw e;
        } catch (IOException e) {
            e.printStackTrace();
            throw e;
        } finally {
            try {
                if (httpClient != null)
                    httpClient.close();
            } catch (Exception e) {
                e.printStackTrace();
                throw e;
            }
        }
    }
    
    private static void out(String newLine) {
        System.out.println(newLine);
        LOG.info(newLine);
    }
    }
    		

    最终得到URL:

    http://vod.cn-shanghai.aliyuncs.com?Signature=UI%2FwKfuvTtphzCKHwPhP0ErtLnc%3D&SignatureVersion=1.0&Action=GetVideoPlayAuth&Format=JSON&VideoId=68a4d2629a339db3207963ac073a88cd&SignatureNonce=578a50c1-280d-4a34-bffc-e06aa6b2df76&Version=2017-03-21&AccessKeyId=testId&SignatureMethod=HMAC-SHA1&Timestamp=2017-03-29T12%3A09%3A11Z
    		

    通过HTTP请求的方式向上述URL地址发送HTTP请求,得到响应结果,此处以JSON格式为例:

    {
     "RequestId": "25818875-5F78-4A13-BEF6-D7393642CA58",
     "VideoMeta": {
         "VideoId": "93ab850b4f6f44eab54b6e91d24d81d4",
         "Title": "阿里云VOD",
         "Duration": 135.6,
         "CoverURL": "https://image.example.com/sample.jpg",
         "Status": "Normal"
      },
      "PlayAuth": "sstyYuew678999ew90000000xtt7TYUh"
    }